Preparation method and application of biodegradable special cat litter

Abstract

According to the preparation method and application of the biodegradable special cat litter provided by the invention, efficient, odorless and thorough treatment of cat excrement is realized by constructing a multi-layer synergistic biodegradation system. The core of the system is as follows: firstly, a high-tolerance functional strain is obtained through a composite screening process combining nitrogen ion beam irradiation mutagenesis with multiple stress and brown algae polyphenol; secondly, according to the characteristics of different strains, a multi-mode microbial agent delivery system combining quick release particles, slow release pellets and common bacterial powder is prepared, and quick control over a pollution source and long-acting stable conversion of ammonia gas are achieved; the uricase is embedded by adopting the microcapsules, so that the stability and the catalytic durability of the uricase are remarkably improved; under the combined action of the technologies, finally, the cat litter can rapidly permeate and degrade excrement, ammonia release and peculiar smell generation are effectively controlled, and the comprehensive effects of being small in dosage, long in cleaning period and environmentally friendly are achieved.

Description

Technical Field

[0001] This invention belongs to the field of biodegradable and deodorizing cat litter technology, specifically relating to a method for preparing and applying a biodegradable special cat litter. Background Technology

[0002] In the pet cat litter industry, current technologies for solving waste disposal problems mainly evolve along three directions: physical adsorption, chemical deodorization, and biodegradation. Traditional bentonite and silica gel cat litters rely on physical adsorption, which can encapsulate feces, but their odor removal ability is limited, requiring frequent cleaning and generating a large amount of non-biodegradable waste, resulting in a heavy environmental burden. Subsequent plant-based materials such as tofu litter and pine litter have improved in terms of biodegradability, but their odor removal mechanism is still mainly based on masking or limited adsorption, and cannot fundamentally decompose the complex organic matter that produces odors. Especially when dealing with cat urine with high nitrogen and high uric acid, the effect quickly saturates, and the odor remains obvious.

[0003] In recent years, "biological cat litter," which draws inspiration from the fermentation bed principle in animal husbandry, has become a research hotspot. Its core lies in utilizing microbial communities to decompose excrement. However, directly applying fermentation bed microbial agents, used for treating relatively uniform and large-volume feces from pigs and cattle, to cat litter presents serious technical adaptation defects. First, insufficient microbial tolerance: As obligate carnivores, cats' urine is characterized by point-like discharge and extremely high instantaneous concentrations. The localized extreme osmotic pressure and toxic environment created by urate, ammonia nitrogen, and salt can rapidly inactivate conventional microbial communities, forming "dead zones" and interrupting the biodegradation process. Second, mismatch between function and timeliness: Cat excrement degradation is a process combining rapid initiation and sustained action. Existing mixed microbial agents often release their functions disorderedly, failing to immediately suppress odors and decompose large molecules when pollution occurs, nor can they accurately and continuously eliminate odors during subsequent peak ammonia production periods, resulting in incomplete deodorization. Furthermore, a key component is missing: the high concentration and chemically stable uric acid / urate in cat urine is a persistent source of odor and crystallization. The lack of sufficient and highly active specific decomposing enzymes (such as uricase) in the conventional microbial community makes this component a "bottleneck" in the degradation chain, limiting the overall treatment efficiency and service life.

[0004] These shortcomings not only result in a poor user experience—requiring frequent cleaning or enduring odors—but also make it difficult to truly realize the concept of "long-lasting, no-clean" bio-litter. Therefore, developing a cat litter preparation technology that can simultaneously address the three major challenges of localized bacterial tolerance, the timing of functional release, and the specific degradation of stubborn components has become crucial for driving the industry towards truly environmentally friendly and convenient practices. This would not only significantly reduce the daily burden on pet owners and improve the living environment, but also reduce the environmental impact of pet waste at its source, possessing significant social and market value. Summary of the Invention

[0005] This invention discloses a method for preparing biodegradable cat litter to solve any of the above-mentioned or potential problems in the prior art. To solve the above-mentioned technical problems, the specific preparation method of this application is as follows:

[0006] The product comprises the following components by weight: 0.4-0.6 parts of compound microbial powder, 17-22 parts of activator, 0.2-0.4 parts of bio-enzyme microcapsules, and 90-110 parts of fermentation substrate carrier.

[0007] The activator includes: 10-12 parts of 30-mesh filtered corn flour, 6-8 parts of 30-mesh filtered wheat bran, and 1-2 parts of 30-mesh filtered rice bran.

[0008] The fermentation bedding carrier includes 50-60 parts of 5-mesh filtered sawdust and 40-50 parts of rice husks. The mixing process is carried out using a stirring device for 30-50 minutes at a speed of 50-100 rpm until the mixture is homogeneous.

[0009] The preparation of composite microbial powder particles includes the following steps: irradiation mutagenesis to select strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles.

[0010] Among them, irradiation-induced mutation involved isolating *Pseudomonas putida* from soil and cat feces, along with other bacteria such as *Bacillus amyloliquefaciens*, *Bacillus subtilis*, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein-decomposing bacteria, lactic acid bacteria, *Azotobacter chroococcus*, and lipolytic bacteria, and preparing suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and plated onto LBG agar plates containing multiple stress factors and 0.01%-0.05% (w / w) brown algal polyphenols. Selective pressures were set in the plates with gradient concentrations of 2%, 4%, and 6% NaCl, 0.1%, 0.2%, and 0.4% (NH₄)₂SO₄, and 0.5%, 1.0%, and 2.0% uric acid, respectively. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0011] The process of fermenting compound microbial powder into single-strain cultures, propagating the culture, and freeze-drying includes: fermenting the irradiated and mutagenized strains separately; culturing each strain separately in LBG medium for 24-36 hours with an inoculum size of 1-2% and a shaking speed of 180-200 rpm; the LBG medium comprising 50g glucose, 10g peptone, 5g yeast extract, 10g sodium chloride, and 1000ml pure water to obtain fresh fermentation culture; and classifying the fresh fermentation culture into growth-promoting strain a and decomposing strain b.

[0012] The effective viable count of the above bacterial solution was 1.35 × 10⁻⁶. 9 -2.4×10 9 cfu / ml; add fresh sugarcane molasses culture medium to the above bacterial agent at a mass concentration of 2-5%; add the bacterial complex to a fermenter for static fermentation to obtain the bacterial solution after propagation; freeze-dry the bacterial solution obtained from propagation to obtain highly active bacterial powder.

[0013] Among them, growth-promoting bacteria strain a includes Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; decomposing bacteria strain b is a mixture of fecal decomposing bacteria, protein decomposing bacteria, and fat decomposing bacteria in a mass ratio of 0.5-1:0.5-1:0.2-0.5.

[0014] Among them, the above-mentioned Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria and Azotobacter chrysotile also include the process of making them into functional bacterial powder particles.

[0015] The preparation of functional bacterial powder particles includes preparing rapid-release bacterial agent particles from 2-5 parts of Bacillus subtilis and 2-5 parts of Bacillus amyloliquefaciens; and preparing slow-release ammonia-removing bacterial microspheres from 5-10 parts of nitrifying bacteria, 5-10 parts of photosynthetic bacteria and 5-10 parts of Azotobacter chrysophagus.

[0016] The rapid-release microbial agent granules consist of: uniformly mixing 2-5 parts of Bacillus subtilis and 2-5 parts of Bacillus amyloliquefaciens, 2-5 parts of skim milk and 2-5 parts of trehalose to obtain a mixed microbial powder; then mixing low-substituted hydroxypropyl cellulose and povidone at a mass ratio of 2:1 as a disintegrant; in a fluidized bed granulator, mixing the disintegrant material and the mixed microbial powder at a mass ratio of 3:1, and granulating with a 5% PVA solution via bottom spraying, controlling the inlet air temperature at 50℃, the material temperature at 35-40℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min; after granulation, drying is performed until the moisture content is ≤12%;

[0017] The slow-release ammonia-removing microspheres consist of: 5-10 parts nitrifying bacteria, 5-10 parts photosynthetic bacteria, and 5-10 parts *Azotobacter chrysophagus* mixed with a 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1; spraying the mixture with particles of 0.8-1.0 mm in diameter onto a microcrystalline cellulose pellet core, controlling the amount of bacterial solution adsorbed to achieve a weight gain of 30% of the initial pellet core mass; then, coating the pellets using a fluidized bed coating machine; with an inlet air temperature of 35℃, a spray pressure of 0.15 MPa, and a spray rate of 4 mL / min, until the coating layer weight gain reaches 20-25% of the total pellet core mass. After coating, the pellets are dried at 30℃ for 2 hours to obtain the slow-release ammonia-removing microspheres.

[0018] The mixing of the compound microbial powder particles includes: mixing 1-2 parts of fast-release bacterial agent particles, 0.8-1.5 parts of slow-release ammonia-removing microcapsules, 1-1.5 parts of lactic acid bacteria powder, 0.8-1.2 parts of *Pseudomonas putida*, and 4-5 parts of freeze-dried compound bacterial powder b at 200 rpm for 20 min.

[0019] The bio-enzyme microcapsules consist of: dissolving 1-2 parts of spirulina protein and 10 parts of uricase in a 0.1 mol / L phosphate buffer solution at pH 7.0 to prepare a uricase solution with a concentration of 20-30 mg / mL as the aqueous phase; dissolving polyurethane in dichloromethane to prepare an organic solution with a concentration of 50 mg / mL as the oil phase; mixing the oil phase volume to the aqueous phase volume at a high-speed shear rate of 10,000 rpm for 2 minutes to form a stable W / O promulgation; pouring the promulgation into 500 mL of an aqueous solution containing 1% polyvinyl alcohol by mass, stirring continuously at 500 rpm, and evaporating in a 40°C water bath for 4 hours to completely remove dichloromethane and solidify the microcapsule walls; centrifuging at 5000 rpm for 10 minutes to collect the solid, washing three times with deionized water, pre-freezing at -40°C, and freeze-drying under vacuum for 24 hours to obtain bio-enzyme microcapsules with a particle size of 50-200 micrometers.

[0020] The advantages and beneficial effects of this invention are as follows:

[0021] 1. This invention, through systematic process design and multi-component synergistic effects, achieves efficient, odorless, and complete biodegradation of cat excrement. Its beneficial effects are mainly reflected in the following aspects:

[0022] 2. First, in the strain selection stage, a composite screening method combining nitrogen ion beam irradiation mutagenesis with multiple stress factors and brown algal polyphenols was employed. Conventional mutagenesis relies solely on physical or chemical mutagenesis, resulting in limited improvement in strain tolerance. However, this invention simultaneously applies gradient concentrations of salt, ammonium, and uric acid stress during the post-mutation recovery culture, and adds 0.01%–0.05% brown algal polyphenols. As natural antioxidants and membrane stabilizers, brown algal polyphenols effectively alleviate oxidative damage caused by mutagenesis, improving the survival rate and colonization ability of mutant strains under harsh environments, thereby screening for functional strains with both high enzyme activity and strong environmental tolerance. Strains such as *Pseudomonas putida* and *Bacillus amyloliquefaciens* obtained using this method can maintain activity in the local "dead zone" of cat urine with high salt, high ammonia nitrogen, and high uric acid concentrations, avoiding the "burning of bacteria" phenomenon.

[0023] 3. Secondly, in view of the temporal and spatial characteristics of odor release from cat excrement, the present invention has carried out the following treatment on the compound microbial powder particles: (1) Bacillus subtilis and Bacillus amyloliquefaciens are made into fast-release bacterial agent particles. The disintegration system of low-substituted hydroxypropyl cellulose and povidone is used to make it disintegrate and release rapidly after contact with cat feces and urine, rapidly decompose large molecular organic matter such as protein and cellulose, and secrete antibacterial substances to inhibit pathogens, thereby controlling the source of pollution and odor generation at the first time; (2) Nitrifying bacteria, photosynthetic bacteria and Azotobacter chroococcus are made into slow-release ammonia-removing microspheres. The release rate is controlled by Eudragit S100 coating layer, so that it can play a continuous and stable role during the peak period of ammonia production from cat urine hydrolysis, gradually converting ammonia nitrogen into nitrate nitrogen or assimilating and fixing it, avoiding the instantaneous release of ammonia gas, and achieving long-term ammonia removal. The decomposing bacteria strain b (such as cat feces-decomposing bacteria) is mainly responsible for degrading common organic matter such as oils and proteins. Its function does not require immediate or slow-release regulation, so it is added directly in the form of bacterial powder to ensure reasonable overall cost. This multi-modal delivery system achieves synergistic and precise regulation of bacterial functions.

[0024] 4. Furthermore, addressing the extremely high concentrations and chemically stable uric acid / urate crystals in cat urine, this invention prepares uricase as microcapsules with spirulina protein-polyurethane as the wall material. Spirulina protein is rich in active ingredients such as phycocyanin, which not only acts as a stabilizer to effectively protect the activity of uricase during preparation and storage, but also possesses natural antibacterial and antioxidant properties, further improving the local microecological environment of the cat litter. Compared to wall materials such as ordinary gelatin or gum arabic, the protective layer formed by spirulina protein is denser and has better biocompatibility, ensuring that uricase maintains high activity in the high-salt, high-organic-matter environment of the cat litter and achieves slow release, persistently catalyzing the decomposition of uric acid into urea, providing a substrate for subsequent microbial treatment, and directly improving the problem that conventional cat litter and ordinary fermentation beds cannot effectively decompose uric acid crystals.

[0025] 5. In summary, the core advantage of this invention lies in constructing a multi-layered, synergistic biodegradation system: the highly tolerant strains selected through targeted mutagenesis solve the survival problem of the bacterial community in extreme local environments; the functionalized bacterial agents enable the time-controlled release of key bacterial communities; and the bio-enzyme microcapsules provide specific and persistent catalysis against stubborn uric acid. All of these factors together ensure that the cat litter can still achieve rapid penetration, efficient degradation, ammonia control, and odor elimination even when faced with high concentrations of spot-discharged cat urine, ultimately achieving a comprehensive effect of low dosage, long cleaning cycles, and environmental friendliness. Furthermore, it significantly surpasses the treatment capacity of ordinary mixed bacterial agents or single enzyme preparations, demonstrating its practicality and environmental friendliness in the field of pet waste biological treatment. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the embodiments. The coating liquid used in the following sustained-release ammonia-removing microcapsules for coating is an enteric coating solution. The preparation of the enteric coating solution is as follows: 10g of triethyl citrate is dissolved in 950ml of 95% ethanol solution, Eudragit S100 powder is slowly added under continuous stirring, and homogenization is carried out at 5000rpm for 20min to obtain the enteric coating solution.

[0027] Example 1

[0028] 1. The preparation of compound microbial powder particles includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles;

[0029] (1) Irradiation mutagenesis: Pseudomonas putida was isolated from soil and cat feces, along with other Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein decomposing bacteria, lactic acid bacteria, Azotobacter chroococcus, and lipid decomposing bacteria, which were respectively prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and spread onto LBG agar plates containing multiple stress factors and 0.03% (w / w) brown algal polyphenols for cultivation. The plates were incubated with gradient concentrations of NaCl (2%, 4%, 6%), (NH₄)₂SO₄ (0.1%, 0.2%, 0.4%), and uric acid (0.5%, 1.0%, 2.0%) as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0030] (2) Single-strain fermentation, bacterial culture propagation, and freeze-drying include: fermenting the strains selected by irradiation mutagenesis separately; each strain is cultured separately in LBG medium for 30h: the inoculum amount is 1.5%, the shaking speed is 190rpm, the LBG medium includes 50g glucose, 10g peptone, 5g yeast extract, 10g sodium chloride, and 1000ml pure water to obtain fresh fermentation liquid; the above fresh fermentation liquid includes growth-promoting bacteria a and decomposing bacteria b; the growth-promoting bacteria a is fermented by Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria b is prepared by mixing cat feces decomposing bacteria, protein decomposing bacteria, and oil decomposing bacteria in a mass ratio of 2:2:1 to obtain compound bacterial culture b.

[0031] (3) The effective viable count of the above bacterial solution is >1.35×10 9 cfu / ml; fresh sugarcane molasses culture medium was added to the above bacterial agent at a mass concentration of 4%; the bacterial complex was added to a fermenter for static fermentation to obtain the bacterial solution after propagation; the bacterial solution obtained from propagation was freeze-dried to obtain highly active bacterial powder.

[0032] (4) The compound microbial powder particles are used to make functional bacterial agents, including: Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria and Azotobacter chrysotile in growth-promoting bacteria a are respectively prepared into fast-release bacterial agent particles and slow-release ammonia-removing bacteria micro pellets.

[0033] Rapid-release bacterial agent granules: 0.4g of Bacillus subtilis and 0.4g of Bacillus amyloliquefaciens, 0.4g of skim milk and 0.4g of trehalose were uniformly mixed to obtain a mixed bacterial powder. Then, low-substituted hydroxypropyl cellulose and povidone were mixed at a mass ratio of 2:1 as disintegrants. In a fluidized bed granulator, the disintegrants and mixed bacterial powders were mixed at a mass ratio of 3:1, and granulation was carried out using a bottom spray method with 5% PVA solution. The inlet air temperature was controlled at 50℃, the material temperature at 38℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min. After granulation, the granules were dried until the moisture content was ≤12%.

[0034] Slow-release ammonia-removing microcapsules: 0.8g of nitrifying bacteria, 0.8g of photosynthetic bacteria, and 0.8g of Azotobacter chrysoprase are mixed with 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1. This mixture is then sprayed onto microcrystalline cellulose pellets with a particle size of 0.9mm, controlling the amount of bacterial solution adsorbed to achieve a weight gain of 30% of the initial pellet mass. Next, a fluidized bed coating machine is used for coating. The inlet air temperature is 35℃, the spray pressure is 0.15MPa, and the spray rate is 4mL / min, until the coating layer weight gain reaches 22% of the total pellet mass. After coating, the pellets are dried at 30℃ for 2 hours to obtain the slow-release ammonia-removing microcapsules.

[0035] (5) Mixing of compound microbial powder particles: 1.5g of fast-release bacterial agent particles, 1.2g of slow-release ammonia-removing microcapsules, 1.3g of lactic acid bacteria powder, 1g of putrefactive Pseudomonas putrefactivee, and 4.5g of freeze-dried compound bacterial powder b are mixed at 200rpm for 20min.

[0036] 2. Bioenzyme Microcapsules: 1.5g of spirulina protein and 10g of uricase were dissolved in 0.1mol / L phosphate buffer at pH 7.0 to prepare a uricase solution with a concentration of 25mg / mL as the aqueous phase; polyurethane was dissolved in dichloromethane to prepare an organic solution with a concentration of 50mg / mL as the oil phase; the oil phase volume: aqueous phase volume = 5:1 was mixed under high-speed shearing at 10000rpm for 2 minutes to form a stable W / O promulgated emulsion; the promulgated emulsion was poured into 500mL of an aqueous solution containing 1% by mass of polyvinyl alcohol, stirred continuously at 500rpm, and evaporated in a 40℃ water bath for 4 hours to completely remove dichloromethane and solidify the microcapsule walls; the solid was collected by centrifugation at 5000rpm for 10 minutes, washed three times with deionized water, pre-frozen at -40℃, and freeze-dried under vacuum for 24 hours to obtain bioenzyme microcapsules with a particle size of 120 micrometers.

[0037] 3. Cat litter mixing: Take 5g of compound microbial powder granules, 110g of 30-mesh filtered corn flour, 70g of 30-mesh filtered wheat bran, 15g of 30-mesh filtered rice bran; 3g of bio-enzyme microcapsules, 550g of 5-mesh filtered sawdust, and 450g of rice husks. Mix the ingredients using a stirring device for 40 minutes at a speed of 80 rpm until well combined.

[0038] Example 2

[0039] 1. The preparation of compound microbial powder particles includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles;

[0040] (1) Irradiation mutagenesis: Pseudomonas putida was isolated from soil and cat feces, along with other Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein decomposing bacteria, lactic acid bacteria, Azotobacter chroococcus, and lipid decomposing bacteria, which were respectively prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and spread onto LBG agar plates containing multiple stress factors and 0.05% (w / w) brown algal polyphenols for cultivation. The plates were incubated with gradient concentrations of NaCl (2%, 4%, 6%), (NH₄)₂SO₄ (0.1%, 0.2%, 0.4%), and uric acid (0.5%, 1.0%, 2.0%) as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0041] (2) Single-strain fermentation, bacterial culture propagation, and freeze-drying include: fermenting the strains selected by irradiation mutagenesis separately; each strain is cultured separately in LBG medium for 24 hours: the inoculum amount is 2%, the shaking speed is 200 rpm, the LBG medium includes 50 g glucose, 10 g peptone, 5 g yeast extract, 10 g sodium chloride, and 1000 ml pure water to obtain fresh fermentation liquid; the above fresh fermentation liquid includes growth-promoting bacteria a and decomposing bacteria b; the growth-promoting bacteria a is fermented by Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria b is prepared by mixing cat feces decomposing bacteria, protein decomposing bacteria, and oil decomposing bacteria in a mass ratio of 2:1:1 to obtain compound bacterial culture b.

[0042] (3) The effective viable count of the above bacterial solution is >1.35×10 9 cfu / ml; fresh sugarcane molasses culture medium was added to the above bacterial agent at a mass concentration of 5%; the bacterial complex was added to a fermenter for static fermentation to obtain the bacterial solution after propagation; the bacterial solution obtained from propagation was freeze-dried to obtain highly active bacterial powder.

[0043] (4) The compound microbial powder particles are used to make functional bacterial agents, including: Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria and Azotobacter chrysotile in growth-promoting bacteria a are respectively prepared into fast-release bacterial agent particles and slow-release ammonia-removing bacteria micro pellets.

[0044] Rapid-release bacterial agent granules: 0.5g of Bacillus subtilis and 0.5g of Bacillus amyloliquefaciens, 0.2g of skim milk and 0.5g of trehalose were uniformly mixed to obtain a mixed bacterial powder. Then, low-substituted hydroxypropyl cellulose and povidone were mixed at a mass ratio of 2:1 as disintegrants. In a fluidized bed granulator, the disintegrants and mixed bacterial powders were mixed at a mass ratio of 3:1, and granulation was carried out using a bottom spray method with 5% PVA solution. The inlet air temperature was controlled at 50℃, the material temperature at 40℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min. After granulation, the granules were dried until the moisture content was ≤12%.

[0045] Slow-release ammonia-removing microspheres: 0.5g of nitrifying bacteria, 1g of photosynthetic bacteria, and 0.5g of Azotobacter chrysoprase are mixed with 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1. This mixture is then sprayed onto microcrystalline cellulose pellets with a particle size of 1.0mm, controlling the amount of bacterial solution adsorption to achieve a weight gain of 30% of the initial pellet mass. Next, a fluidized bed coating machine is used for coating. The inlet air temperature is 35℃, the spray pressure is 0.15MPa, and the spray rate is 4mL / min, until the coating layer weight gain reaches 20% of the total pellet mass. After coating, the pellets are dried at 30℃ for 2 hours to obtain slow-release ammonia-removing microspheres.

[0046] (5) Mixing of compound microbial powder particles: 2g of fast-release bacterial agent particles, 0.8g of slow-release ammonia-removing microcapsules, 1.5g of lactic acid bacteria powder, 0.8g of putrefactive Pseudomonas putrefactiveis, and 5g of freeze-dried compound bacterial powder b are mixed at 200rpm for 20min to obtain the mixture.

[0047] 2. Bioenzyme Microcapsules: 1g of spirulina protein and 10g of uricase were dissolved in 0.1mol / L phosphate buffer at pH 7.0 to prepare a uricase solution with a concentration of 30mg / mL as the aqueous phase; polyurethane was dissolved in dichloromethane to prepare an organic solution with a concentration of 50mg / mL as the oil phase; the oil phase volume: aqueous phase volume = 5:1 was mixed under high-speed shearing at 10000rpm for 2 minutes to form a stable W / O promulgated emulsion; the promulgated emulsion was poured into 500mL of an aqueous solution containing 1% by mass of polyvinyl alcohol, stirred continuously at 500rpm, and evaporated in a 40℃ water bath for 4 hours to completely remove dichloromethane and solidify the microcapsule walls; the solid was collected by centrifugation at 5000rpm for 10 minutes, washed three times with deionized water, pre-frozen at -40℃, and freeze-dried under vacuum for 24 hours to obtain bioenzyme microcapsules with a particle size of 50 micrometers.

[0048] 3. Cat litter mixing: Take 6g of compound microbial inoculum powder, 100g of 30-mesh filtered corn flour, 80g of 30-mesh filtered wheat bran, 10g of 30-mesh filtered rice bran; 4g of bio-enzyme microcapsules, 500g of 5-mesh filtered sawdust, and 500g of rice husks. Mix the ingredients using a stirring device for 50 minutes at a speed of 100 rpm until well combined.

[0049] Example 3

[0050] 1. The preparation of compound microbial powder particles includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles;

[0051] (1) Irradiation mutagenesis: Pseudomonas putida was isolated from soil and cat feces, along with other Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein decomposing bacteria, lactic acid bacteria, Azotobacter chroococcus, and lipid decomposing bacteria, which were respectively prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and spread onto LBG agar plates containing multiple stress factors and 0.01% by mass of brown algal polyphenols for cultivation. The plates were incubated with gradient concentrations of NaCl (2%, 4%, 6%), (NH₄)₂SO₄ (0.1%, 0.2%, 0.4%), and uric acid (0.5%, 1.0%, 2.0%) as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0052] (2) Single-strain fermentation, bacterial culture propagation, and freeze-drying include: fermenting the strains selected by irradiation mutagenesis separately; each strain is cultured separately in LBG medium for 36 hours: the inoculum amount is 1%, the shaking speed is 180 rpm, the LBG medium includes 50 g glucose, 10 g peptone, 5 g yeast extract, 10 g sodium chloride, and 1000 ml pure water to obtain fresh fermentation liquid; the above fresh fermentation liquid includes growth-promoting bacteria a and decomposing bacteria b; the growth-promoting bacteria a is fermented by Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria b is prepared by mixing cat feces decomposing bacteria, protein decomposing bacteria, and oil decomposing bacteria in a mass ratio of 5:10:2 to obtain compound bacterial culture b.

[0053] (3) The effective viable count of the above bacterial solution is >1.35×10 9 cfu / ml; fresh sugarcane molasses culture medium was added to the above bacterial agent at a mass concentration of 2%; the bacterial complex was added to a fermenter for static fermentation to obtain the bacterial solution after propagation; the bacterial solution obtained from propagation was freeze-dried to obtain highly active bacterial powder.

[0054] (4) The compound microbial powder particles are used to make functional bacterial agents, including: Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria and Azotobacter chrysotile in growth-promoting bacteria a are respectively prepared into fast-release bacterial agent particles and slow-release ammonia-removing bacteria micro pellets.

[0055] Rapid-release bacterial agent granules: 0.2g of Bacillus subtilis and 0.2g of Bacillus amyloliquefaciens, 0.5g of skim milk and 0.2g of trehalose were uniformly mixed to obtain a mixed bacterial powder. Then, low-substituted hydroxypropyl cellulose and povidone were mixed at a mass ratio of 2:1 as disintegrants. In a fluidized bed granulator, the disintegrants and mixed bacterial powders were mixed at a mass ratio of 3:1, and granulation was carried out using a bottom spray method with 5% PVA solution. The inlet air temperature was controlled at 50℃, the material temperature at 35℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min. After granulation, the granules were dried until the moisture content was ≤12%.

[0056] Slow-release ammonia-removing microspheres: 1g of nitrifying bacteria, 0.5g of photosynthetic bacteria, and 1g of Azotobacter chrysoprase are mixed with a 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1. This mixture is then sprayed onto microcrystalline cellulose pellets with a particle size of 0.8mm, controlling the amount of bacterial solution adsorption to achieve a weight gain of 30% of the initial pellet mass. Next, a fluidized bed coating machine is used for coating. The inlet air temperature is 35℃, the spray pressure is 0.15MPa, and the spray rate is 4mL / min, until the coating layer weight gain reaches 25% of the total pellet mass. After coating, the pellets are dried at 30℃ for 2 hours to obtain the slow-release ammonia-removing microspheres.

[0057] (5) Mixing of compound microbial powder particles: 1g of fast-release bacterial agent particles, 1.5g of slow-release ammonia-removing microcapsules, 1g of lactic acid bacteria powder, 1.2g of putrefactive Pseudomonas putrefactiveis, and 4g of freeze-dried compound bacterial powder b are mixed at 200rpm for 20min to obtain the mixture.

[0058] 2. Bioenzyme Microcapsules: 2g of spirulina protein and 10g of uricase were dissolved in a 0.1mol / L phosphate buffer solution at pH 7.0 to prepare a uricase solution with a concentration of 20mg / mL as the aqueous phase; polyurethane was dissolved in dichloromethane to prepare an organic solution with a concentration of 50mg / mL as the oil phase; the oil phase volume: aqueous phase volume = 5:1 was mixed under high-speed shearing at 10000rpm for 2 minutes to form a stable W / O promulgated emulsion; the promulgated emulsion was poured into 500mL of an aqueous solution containing 1% by mass of polyvinyl alcohol, stirred continuously at 500rpm, and evaporated in a 40℃ water bath for 4 hours to completely remove dichloromethane and solidify the microcapsule walls; the solid was collected by centrifugation at 5000rpm for 10 minutes, washed three times with deionized water, pre-frozen at -40℃, and freeze-dried under vacuum for 24 hours to obtain bioenzyme microcapsules with a particle size of 200 micrometers.

[0059] 3. Cat litter mixing: Take 4g of compound microbial inoculum powder, 120g of 30-mesh filtered corn flour, 60g of 30-mesh filtered wheat bran, 20g of 30-mesh filtered rice bran; 2g of bio-enzyme microcapsules, 600g of 5-mesh filtered sawdust, and 400g of rice husks. Mix the ingredients using a stirring device for 30 minutes at a speed of 50 rpm until well combined.

[0060] Comparative Example 1

[0061] 1. The preparation of compound microbial powder includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, and freeze drying;

[0062] (1) Irradiation mutagenesis: Pseudomonas putida was isolated from soil and cat feces, along with other Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein decomposing bacteria, lactic acid bacteria, Azotobacter chroococcus, and lipid decomposing bacteria, which were respectively prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and spread onto LBG agar plates containing multiple stress factors and 0.03% (w / w) brown algal polyphenols for cultivation. The plates were incubated with gradient concentrations of NaCl (2%, 4%, 6%), (NH₄)₂SO₄ (0.1%, 0.2%, 0.4%), and uric acid (0.5%, 1.0%, 2.0%) as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0063] (2) Single-strain fermentation, bacterial culture propagation, and freeze-drying include: fermenting the strains selected by irradiation mutagenesis separately; each strain is cultured separately in LBG medium for 30h: the inoculum amount is 1.5%, the shaking speed is 190rpm, the LBG medium includes 50g glucose, 10g peptone, 5g yeast extract, 10g sodium chloride, and 1000ml pure water to obtain fresh fermentation liquid; the above fresh fermentation liquid includes growth-promoting bacteria a and decomposing bacteria b; the growth-promoting bacteria a is fermented by Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria b is prepared by mixing cat feces decomposing bacteria, protein decomposing bacteria, and oil decomposing bacteria in a mass ratio of 2:2:1 to obtain compound bacterial culture b.

[0064] (3) The effective viable count of the above bacterial solution is >1.35×10 9cfu / ml; fresh sugarcane molasses culture medium was added to the above bacterial agent at a mass concentration of 4%; the bacterial complex was added to a fermenter for static fermentation to obtain the bacterial solution after propagation; the bacterial solution obtained from propagation was freeze-dried to obtain highly active bacterial powder.

[0065] (4) Mixing of compound microbial powder: 0.5g of Bacillus amyloliquefaciens powder, 0.5g of Bacillus subtilis powder, 0.5g of Pseudomonas putida powder, 1.3g of lactic acid bacteria powder, 0.4g of nitrifying bacteria powder, 0.4g of photosynthetic bacteria powder, 0.4g of Azotobacter chrysoprase, 1g of Pseudomonas putida powder, and 4.5g of compound microbial powder b are mixed at 200rpm for 20min.

[0066] 2. Cat litter mixing: Take 5g of compound microbial powder, 110g of 30-mesh filtered corn flour, 70g of 30-mesh filtered wheat bran, 15g of 30-mesh filtered rice bran; 3g of uricase, 550g of 5-mesh filtered sawdust, and 450g of rice husks. Mix the ingredients using a stirring device for 40 minutes at a speed of 80 rpm until well combined.

[0067] Comparative Example 2

[0068] 1. The preparation of compound microbial powder particles includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles;

[0069] (1) Ultraviolet mutagenesis: Pseudomonas putida was isolated from soil and cat feces, along with other Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, cat feces-decomposing bacteria, protein-decomposing bacteria, lactic acid bacteria, Azotobacter chroococcus, and lipid-decomposing bacteria, which were respectively prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, 100 μL was evenly spread onto a sterile target plate and dried. Then, it was subjected to mutagenesis treatment with conventional ultraviolet irradiation dose of 15 J / m². The mutagenized bacterial culture was revived and spread on LBG agar plates containing multiple stress factors for cultivation. The plates were set with gradient concentrations of 2%, 4%, and 6% NaCl, 0.1%, 0.2%, and 0.4% (NH4)2SO4, and 0.5%, 1.0%, and 2.0% uric acid as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0070] The remaining single-strain fermentation, bacterial liquid propagation, freeze drying, and the preparation of some bacterial powder into functional bacterial agents, biological enzyme microcapsules, and cat litter mixing are the same as in Example 1.

[0071] Comparative Example 3

[0072] 1. The preparation of compound microbial powder particles includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles;

[0073] (1) Irradiation mutagenesis: Pseudomonas putida was isolated from soil and cat feces, along with other Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein decomposing bacteria, lactic acid bacteria, Azotobacter chroococcus, and lipid decomposing bacteria, which were respectively prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and spread onto LBG agar plates containing multiple stress factors and 0.03% (w / w) brown algal polyphenols for cultivation. The plates were incubated with gradient concentrations of NaCl (2%, 4%, 6%), (NH₄)₂SO₄ (0.1%, 0.2%, 0.4%), and uric acid (0.5%, 1.0%, 2.0%) as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0074] (2) Single-strain fermentation, bacterial culture propagation, and freeze-drying include: fermenting the strains selected by irradiation mutagenesis separately; each strain is cultured separately in LBG medium for 30 hours: the inoculum amount is 1.5%, the shaking speed is 190 rpm, the LBG medium includes 50 g glucose, 10 g peptone, 5 g yeast extract, 10 g sodium chloride, and 1000 ml pure water to obtain fresh fermentation liquid; the above fresh fermentation liquid includes growth-promoting bacteria a and decomposing bacteria b; the growth-promoting bacteria a is fermented by Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria b is prepared by mixing cat feces decomposing bacteria, protein decomposing bacteria, and fat decomposing bacteria in a mass ratio of 2:2:1 to obtain compound bacterial culture b;

[0075] (3) The effective viable count of the above bacterial solution is >1.35×10 9 cfu / ml; fresh sugarcane molasses culture medium was added to the above bacterial agent at a mass concentration of 4%; the bacterial complex was added to a fermenter for static fermentation to obtain the bacterial solution after propagation; the bacterial solution obtained from propagation was freeze-dried to obtain highly active bacterial powder.

[0076] (4) The compound microbial powder particles are used to make functional microbial agents, including: Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria and Azotobacter chrysotile in growth-promoting bacteria a are respectively prepared into fast-release microbial agent particles and slow-release ammonia-removing micro pellets;

[0077] Rapid-release bacterial agent granules: 0.4g of Bacillus subtilis and 0.4g of Bacillus amyloliquefaciens, 0.4g of skim milk and 0.4g of trehalose were uniformly mixed to obtain a mixed bacterial powder. Then, low-substituted hydroxypropyl cellulose and povidone were mixed at a mass ratio of 2:1 as disintegrants. In a fluidized bed granulator, the disintegrants and mixed bacterial powders were mixed at a mass ratio of 3:1, and granulation was carried out using a bottom spray method with 5% PVA solution. The inlet air temperature was controlled at 50℃, the material temperature at 38℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min. After granulation, the granules were dried until the moisture content was ≤12%.

[0078] Slow-release ammonia-removing microcapsules: 0.8g of nitrifying bacteria, 0.8g of photosynthetic bacteria, and 0.8g of Azotobacter chrysoprase are mixed with 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1. This mixture is then sprayed onto microcrystalline cellulose pellets with a particle size of 0.9mm, controlling the amount of bacterial solution adsorbed to achieve a weight gain of 30% of the initial pellet mass. Next, a fluidized bed coating machine is used for coating. The inlet air temperature is 35℃, the spray pressure is 0.15MPa, and the spray rate is 4mL / min, until the coating layer weight gain reaches 22% of the total pellet mass. After coating, the pellets are dried at 30℃ for 2 hours to obtain the slow-release ammonia-removing microcapsules.

[0079] (5) Mixing of compound microbial powder particles: 1.5g of fast-release bacterial agent particles, 1.2g of slow-release ammonia-removing microcapsules, 1.3g of lactic acid bacteria powder, 1g of putrefactive Pseudomonas putrefactivee, and 4.5g of freeze-dried compound bacterial powder b are mixed at 200rpm for 20min.

[0080] 2. Cat litter mixing: Take 5g of compound microbial inoculum powder, 110g of 30-mesh filtered corn flour, 70g of 30-mesh filtered wheat bran, 15g of 30-mesh filtered rice bran; 3g of urease, 550g of 5-mesh filtered sawdust, and 450g of rice husks. Mix the ingredients using a stirring device for 40 minutes at a speed of 80 rpm until well combined.

[0081] Comparative Example 4

[0082] 1. The preparation of compound microbial powder particles includes the following steps: irradiation mutagenesis selection of strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles;

[0083] (1) Irradiation mutagenesis: Bacillus amyloliquefaciens, Bacillus subtilis, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein decomposing bacteria, lactic acid bacteria, azotobacter chroococcus, and lipid decomposing bacteria were isolated from soil and cat feces and prepared into suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and spread onto LBG agar plates containing multiple stress factors and 0.03% (w / w) brown algal polyphenols for cultivation. The plates were incubated with gradient concentrations of NaCl (2%, 4%, 6%), (NH₄)₂SO₄ (0.1%, 0.2%, 0.4%), and uric acid (0.5%, 1.0%, 2.0%) as selective pressures. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

[0084] (2) Single-strain fermentation, bacterial culture propagation, and freeze-drying include: fermenting the strains selected by irradiation mutagenesis separately; each strain is cultured separately in LBG medium for 30 hours: the inoculum amount is 1.5%, the shaking speed is 190 rpm, the LBG medium includes 50 g glucose, 10 g peptone, 5 g yeast extract, 10 g sodium chloride, and 1000 ml pure water to obtain fresh fermentation liquid; the above fresh fermentation liquid includes growth-promoting bacteria a and decomposing bacteria b; the growth-promoting bacteria a is fermented by Bacillus amyloliquefaciens, Bacillus subtilis, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria b is prepared by mixing cat feces decomposing bacteria, protein decomposing bacteria, and fat decomposing bacteria in a mass ratio of 2:2:1 to obtain compound bacterial culture b;

[0085] (3) The effective viable count of the above bacterial solution is >1.35×10 9 cfu / ml; fresh sugarcane molasses culture medium was added to the above bacterial agent at a mass concentration of 4%; the bacterial complex was added to a fermenter for static fermentation to obtain the bacterial solution after propagation; the bacterial solution obtained from propagation was freeze-dried to obtain highly active bacterial powder.

[0086] (4) The compound microbial powder particles are used to make functional microbial agents, including: Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria and Azotobacter chrysotile in growth-promoting bacteria a are respectively prepared into fast-release microbial agent particles and slow-release ammonia-removing micro pellets;

[0087] Rapid-release bacterial agent granules: 0.4g of Bacillus subtilis and 0.4g of Bacillus amyloliquefaciens, 0.4g of skim milk and 0.4g of trehalose were uniformly mixed to obtain a mixed bacterial powder. Then, low-substituted hydroxypropyl cellulose and povidone were mixed at a mass ratio of 2:1 as disintegrants. In a fluidized bed granulator, the disintegrants and mixed bacterial powders were mixed at a mass ratio of 3:1, and granulation was carried out using a bottom spray method with 5% PVA solution. The inlet air temperature was controlled at 50℃, the material temperature at 38℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min. After granulation, the granules were dried until the moisture content was ≤12%.

[0088] Slow-release ammonia-removing microcapsules: 0.8g of nitrifying bacteria, 0.8g of photosynthetic bacteria, and 0.8g of Azotobacter chrysoprase are mixed with 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1. This mixture is then sprayed onto microcrystalline cellulose pellets with a particle size of 0.9mm, controlling the amount of bacterial solution adsorbed to achieve a weight gain of 30% of the initial pellet mass. Next, a fluidized bed coating machine is used for coating. The inlet air temperature is 35℃, the spray pressure is 0.15MPa, and the spray rate is 4mL / min, until the coating layer weight gain reaches 22% of the total pellet mass. After coating, the pellets are dried at 30℃ for 2 hours to obtain the slow-release ammonia-removing microcapsules.

[0089] (5) Mixing of compound microbial powder particles: 1.5g of fast-release bacterial agent particles, 1.2g of slow-release ammonia-removing microcapsules, 1.3g of lactic acid bacteria powder, and 4.5g of freeze-dried compound bacterial powder b are mixed at 200rpm for 20min to obtain the mixture.

[0090] 2. Bioenzyme Microcapsules: 1.5g of spirulina protein and 10g of uricase were dissolved in 0.1mol / L phosphate buffer at pH 7.0 to prepare a uricase solution with a concentration of 25mg / mL as the aqueous phase; polyurethane was dissolved in dichloromethane to prepare an organic solution with a concentration of 50mg / mL as the oil phase; the oil phase volume: aqueous phase volume = 5:1 was mixed under high-speed shearing at 10000rpm for 2 minutes to form a stable W / O promulgated emulsion; the promulgated emulsion was poured into 500mL of an aqueous solution containing 1% by mass of polyvinyl alcohol, stirred continuously at 500rpm, and evaporated in a 40℃ water bath for 4 hours to completely remove dichloromethane and solidify the microcapsule walls; the solid was collected by centrifugation at 5000rpm for 10 minutes, washed three times with deionized water, pre-frozen at -40℃, and freeze-dried under vacuum for 24 hours to obtain bioenzyme microcapsules with a particle size of 120 micrometers.

[0091] 3. Cat litter mixing: Take 5g of compound microbial powder granules, 110g of 30-mesh filtered corn flour, 70g of 30-mesh filtered wheat bran, 15g of 30-mesh filtered rice bran; 3g of bio-enzyme microcapsules, 550g of 5-mesh filtered sawdust, and 450g of rice husks. Mix the ingredients using a stirring device for 40 minutes at a speed of 80 rpm until well combined.

[0092] Comparative Example 5

[0093] Take 5g of activated carbon, 110g of corn flour filtered through a 30-mesh screen, 70g of wheat bran filtered through a 30-mesh screen, and 15g of rice bran filtered through a 30-mesh screen; 3g of baking soda, 550g of sawdust filtered through a 5-mesh screen, and 450g of rice husks. Mix them using a stirring device for 40 minutes at a speed of 80 rpm until well combined.

[0094] Experiment 1:

[0095] Ammonia nitrogen removal rate test:

[0096] Take 100g of cat litter sample from each group and spread it evenly at the bottom of a 5L sealed container. Alternatively, inject 5ml of 1% ammonia solution into the center of the cat litter sample to simulate urine contamination. Seal the container and let it stand at (25±1)℃ and (50±5)%RH.

[0097] A high-precision ammonia detector was used to measure the headspace ammonia concentration in the container at time points of 0, 1, 4, 12, and 24 hours.

[0098] Ammonia nitrogen removal rate (%) = [(C0-C t ) / C0]×100%

[0099] Where C0 is the initial ammonia concentration, C t Let t be the ammonia concentration at time t.

[0100] The results are shown in Table 1 below.

[0101] Table 1

[0102] Group 1h ammonia nitrogen removal rate / % 4h ammonia nitrogen removal rate / % 12h ammonia nitrogen removal rate / % 24h ammonia nitrogen removal rate / % Example 1 55 85 98 99 Example 2 52 82 96 99 Example 3 50 80 95 98 Comparative Example 1 48 70 82 76 Comparative Example 2 30 59 76 82 Comparative Example 3 38 62 73 81 Comparative Example 4 35 54 69 76 Comparative Example 5 39 43 50 48

[0103] Based on the ammonia nitrogen removal rate data, Examples 1-3 achieved a removal rate of over 50% within 1 hour, which continued to increase over time, exceeding 95% at 12 hours and approaching complete removal (98%-99%) at 24 hours. This indicates that the cat litter system in this invention can respond rapidly and continuously and efficiently degrade ammonia nitrogen. Comparative Example 1 (without functional bacterial agent) showed a decent initial removal rate, but it decreased after 12 hours, indicating that ordinary bacterial powder became inactive due to environmental stress in the later stages, and its degradation ability could not be maintained. Comparative Example 2 (UV mutagenesis) had a low overall removal rate due to insufficient strain tolerance. Comparative Example 3 (uricase not microencapsulated) and Comparative Example 4 (lacking Pseudomonas putida) both had limited ammonia nitrogen degradation efficiency due to the lack of key functions. Comparative Example 5 (traditional physical adsorption) showed a decent removal rate in the early stages, but its sustainability was poor, and it had almost no biodegradation ability, with the lowest removal rate after 24 hours. The advantage of this application lies in the synergistic effect of time-controlled release bacterial agents and stabilizing enzymes, which on the one hand rapidly eliminates ammonia sources, and on the other hand continuously transforms ammonia during the peak period of ammonia production, thereby achieving efficient and long-lasting ammonia nitrogen control.

[0104] Experiment 2: Hydrogen sulfide removal rate test

[0105] Similar to the ammonia nitrogen removal rate test, the pollution source was replaced with 5 ml of 1% sodium sulfide solution. A high-precision hydrogen sulfide detector was used for testing.

[0106] Hydrogen sulfide removal rate (%) = [(C0-C t ) / C0]×100%

[0107] Where C0 is the initial hydrogen sulfide concentration, C t Let be the concentration of hydrogen sulfide at time t.

[0108] The results are shown in Table 2 below.

[0109] Table 2

[0110] Group 1h hydrogen sulfide removal rate / % 4h hydrogen sulfide removal rate / % 12h hydrogen sulfide removal rate / % 24h hydrogen sulfide removal rate / % Example 1 60 92 99 99 Example 2 56 90 98 99 Example 3 54 88 96 98 Comparative Example 1 50 68 79 75 Comparative Example 2 36 56 68 80 Comparative Example 3 45 60 71 83 Comparative Example 4 40 53 64 74 Comparative Example 5 46 56 60 58

[0111] The removal rate of hydrogen sulfide showed a similar trend to that of ammonia nitrogen: Examples 1-3 achieved a removal rate of 88%-92% within 4 hours and nearly complete removal after 12 hours, demonstrating its efficient and rapid sulfide oxidation capability. This is attributed to the immediate action of Bacillus subtilis and Bacillus amyloliquefaciens in the rapidly releasing bacterial agent, as well as the continuous decomposition of sulfur-containing organic matter by strains such as Pseudomonas putida. Comparative Examples 1-4, due to the lack of complete functional design of the bacterial agent or insufficient strain performance, had significantly lower removal rates in the later stages compared to the examples, especially Comparative Examples 2 (UV mutagenesis) and 4 (lacking Pseudomonas putida), which showed a significant decrease, indicating that Pseudomonas putida plays a key role in sulfide degradation; Comparative Example 5 relied solely on physical adsorption, resulting in the lowest removal rate with no continuous improvement. This application, through the combination of highly tolerant strains and a controlled-release system, ensures that the biological oxidation pathway of sulfides can be rapidly initiated and maintained even in high-organic-matter environments like cat litter, thereby completely eliminating odors.

[0112] Experiment 3: Antibacterial performance test (inhibition rate of Escherichia coli and Staphylococcus aureus)

[0113] Test standard reference: Refer to the antibacterial rate test method (shaking flask method) for non-leaching products in QB / T5998-2024 "Pet diaper pads (pants)".

[0114] Preparation of bacterial suspension: *Escherichia coli* (ATCC8739) and *Staphylococcus aureus* (ATCC6538) were cultured separately, and suspensions were prepared to a concentration of 1×10⁻⁶. 6 CFU / mL bacterial suspension.

[0115] Inoculation and culture: 1g of cat litter sample (experimental group) and 1g of quartz sand (blank control group) were placed in sterile conical flasks, and 50mL of bacterial suspension was added to each. The samples were cultured in a constant temperature shaker at 150rpm for 24 hours at (37±1)℃.

[0116] Viable cell count: Take out the culture medium, perform serial dilution, spread it on nutrient agar plates, incubate at 37°C for 24 hours, and then count the colonies.

[0117] Calculation formula:

[0118] Antibacterial rate (%) = [(CFUcontrol - CFUsample) / CFUcontrol] × 100%

[0119] Wherein, CFUcontrol is the average colony count of the blank control group, and CFUsample is the average colony count of the experimental group.

[0120] The results are shown in Table 3 below.

[0121] Table 3

[0122] Group Escherichia coli inhibition rate / % Staphylococcus aureus inhibition rate / % Example 1 99.6 99.5 Example 2 99.3 99.1 Example 3 99.0 98.8 Comparative Example 1 93.5 92.5 Comparative Example 2 74.5 73.7 Comparative Example 3 83.2 85.2 Comparative Example 4 80.7 79.6 Comparative Example 5 65.8 62.8

[0123] In terms of antibacterial performance, Examples 1-3 showed inhibition rates of over 98.8% against Escherichia coli and Staphylococcus aureus, approaching complete inhibition. This is mainly attributed to the antibacterial substances secreted by Bacillus in the rapidly releasing bacterial agent particles, the competitive inhibition effect of lactic acid bacteria, and the natural antibacterial properties of the spirulina protein wall material. Comparative Example 1 (mixture of ordinary bacterial powder) showed an inhibition rate of approximately 92%-93%, indicating that the bacterial community still had some effect, but lacked a rapid release mechanism, and its effect was not as good as the examples. Comparative Examples 2-4 showed a further decrease in inhibition rate due to poor mutagenesis, insufficient enzyme protection, or lack of bacterial species. Comparative Example 5 (traditional material) showed almost no biological antibacterial ability. The advantage of this application lies in the construction of a multi-layered biological antibacterial system through the design of functionalized bacterial agents and the assistance of microcapsule wall materials. This system can not only rapidly inhibit the proliferation of pathogenic bacteria, but also maintain the hygiene and safety of the cat litter microenvironment through continuous bacterial colonization, thereby significantly improving the hygiene and safety of use.

[0124] More importantly, the cat litter of this invention fundamentally abandons the traditional clumping and adsorption method, achieving in-situ biodegradation of excrement. Its core lies in the synergistic effect of composite microbial powder particles and bio-enzyme microcapsules. When excrement comes into contact with the cat litter, the rapidly released microbial particles immediately activate, decomposing large organic molecules and suppressing odors; the slow-release ammonia-removing microspheres then continue to act, gradually converting harmful substances such as ammonia nitrogen; simultaneously, the bio-enzyme microcapsules target and decompose stubborn uric acid. This multi-stage, continuous biological process allows the organic matter in feces and urine to be efficiently and thoroughly decomposed into water, carbon dioxide, and a small amount of stable humus by the microbial community, eliminating the need for manual removal of clumping. This not only greatly reduces the daily cleaning burden on pet owners, achieving a "long-lasting, maintenance-free" user experience, but also eliminates the generation of solid waste at the source, truly embodying the unity of environmental protection and convenience.

Claims

1. A method for preparing a biodegradable special cat litter, characterized in that: It includes the following components: 0.4-0.6 parts of compound microbial powder, 17-22 parts of activator, 0.2-0.4 parts of bio-enzyme microcapsules, and 90-110 parts of fermentation substrate carrier; The activator comprises: 10-12 parts of 30-mesh filtered corn flour, 6-8 parts of 30-mesh filtered wheat bran, and 1-2 parts of 30-mesh filtered rice bran; The fermentation bedding carrier comprises: 50-60 parts of 5-mesh filtered sawdust and 40-50 parts of rice husks. The mixing process is carried out using a stirring device for 30-50 minutes at a speed of 50-100 rpm until the mixture is homogeneous. The preparation of the composite microbial powder particles includes the following steps: irradiation mutagenesis to select strains, single-strain fermentation, bacterial liquid propagation, freeze drying, and mixing of some of the bacterial powder into functional microbial powder particles. The irradiation-induced mutation involved isolating *Pseudomonas putida* from soil and cat feces, along with other bacteria such as *Bacillus amyloliquefaciens*, *Bacillus subtilis*, nitrifying bacteria, photosynthetic bacteria, fecal decomposing bacteria, protein-decomposing bacteria, lactic acid bacteria, *Azotobacter chroococcus*, and lipolytic bacteria, and preparing suspensions with a concentration of 1×10⁻⁶. 8 CFU / mL, take 100 μL and spread it evenly on a sterile target plate and dry it. Then, inject it with an energy of 25 keV and an injection dose of 1.5 × 10⁻⁶. 15 Irradiation mutagenesis was performed using a nitrogen ion beam with ions / cm². The mutagenized bacterial culture was then revived and plated onto LBG agar plates containing multiple stress factors and 0.01%-0.05% (w / w) brown algal polyphenols. Selective pressures were set in the plates with gradient concentrations of 2%, 4%, and 6% NaCl, 0.1%, 0.2%, and 0.4% (NH₄)₂SO₄, and 0.5%, 1.0%, and 2.0% uric acid, respectively. After incubation at 30°C for 72 hours, single colonies that could grow normally under the highest concentration of each stress factor were screened out, thus identifying highly active mutant strains.

2. The method for preparing biodegradable cat litter according to claim 1, characterized in that: The fermentation of the compound microbial powder into single-strain cultures, the propagation of the culture, and the freeze-drying process include: fermenting the irradiated and mutagenized strains separately; culturing each strain separately in LBG medium for 24-36 hours: the inoculum size is 1-2%, the shaking speed is 180-200 rpm, and the LBG medium includes 50g glucose, 10g peptone, 5g yeast extract, 10g sodium chloride, and 1000ml pure water to obtain fresh fermentation culture; classifying the above fresh fermentation culture into growth-promoting strain a and decomposing strain b. The effective viable count of the above bacterial solution was 1.35 × 10⁻⁶. 9 -2.4×10 9 cfu / ml; add fresh sugarcane molasses culture medium to the above bacterial agent at a mass concentration of 2-5%; add the bacterial complex to a fermenter for static fermentation to obtain the bacterial solution after propagation; freeze-dry the bacterial solution obtained from propagation to obtain highly active bacterial powder.

3. The method for preparing biodegradable cat litter according to claim 2, characterized in that: The growth-promoting bacteria strain a includes Bacillus amyloliquefaciens, Bacillus subtilis, Pseudomonas putida, lactic acid bacteria, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chroococcus; the decomposing bacteria strain b is a mixture of fecal decomposing bacteria, protein decomposing bacteria, and fat decomposing bacteria in a mass ratio of 0.5-1:0.5-1:0.2-0.

5.

4. The method for preparing biodegradable cat litter according to claim 3, characterized in that: The Bacillus subtilis, Bacillus amyloliquefaciens, nitrifying bacteria, photosynthetic bacteria, and Azotobacter chrysotile also include the process of preparing them into functional bacterial powders.

5. The method for preparing biodegradable cat litter according to claim 4, characterized in that: The preparation of functional bacterial powder particles includes preparing rapid-release bacterial agent particles from 2-5 parts of Bacillus subtilis and 2-5 parts of Bacillus amyloliquefaciens; and preparing slow-release ammonia-removing bacterial microspheres from 5-10 parts of nitrifying bacteria, 5-10 parts of photosynthetic bacteria and 5-10 parts of Azotobacter chrysophagus.

6. The method for preparing biodegradable cat litter according to claim 5, characterized in that: The rapid-release bacterial agent granules comprise: 2-5 parts of Bacillus subtilis and 2-5 parts of Bacillus amyloliquefaciens, 2-5 parts of skim milk and 2-5 parts of trehalose are uniformly mixed to obtain a mixed bacterial powder; then, low-substituted hydroxypropyl cellulose and povidone are mixed at a mass ratio of 2:1 as disintegrants; in a fluidized bed granulator, the disintegrants and mixed bacterial powders are mixed at a mass ratio of 3:1, and granulation is performed using a bottom spray method with a 5% PVA solution. The inlet air temperature is controlled at 50℃, the material temperature at 35-40℃, the atomization pressure at 0.2MPa, and the spray rate at 5mL / min. After granulation, the granules are dried until the moisture content is ≤12%.

7. The method for preparing biodegradable cat litter according to claim 5, characterized in that: The slow-release ammonia-removing microspheres comprise: 5-10 parts of nitrifying bacteria, 5-10 parts of photosynthetic bacteria, and 5-10 parts of Azotobacter chrysoprase, mixed with a 3% hydroxypropyl methylcellulose solution at a solid-liquid ratio of 1:1; the mixture is then sprayed onto a microcrystalline cellulose core with a particle size of 0.8-1.0 mm, controlling the amount of bacterial solution adsorption to achieve a weight gain of 30% of the initial core mass; subsequently, a fluidized bed coating machine is used for coating; the inlet air temperature is 35℃, the spray pressure is 0.15 MPa, and the spray rate is 4 mL / min, until the coating layer weight gain reaches 20-25% of the total core mass. After coating, the microspheres are dried at 30℃ for 2 hours to obtain the slow-release ammonia-removing microspheres.

8. The method for preparing biodegradable cat litter according to claim 1, characterized in that: The mixing of the composite microbial powder particles includes: mixing 1-2 parts of fast-release bacterial agent particles, 0.8-1.5 parts of slow-release ammonia-removing microcapsules, 1-1.5 parts of lactic acid bacteria powder, 0.8-1.2 parts of *Pseudomonas putida*, and 4-5 parts of freeze-dried composite bacterial powder b at 200 rpm for 20 min.

9. The method for preparing biodegradable cat litter according to claim 1, characterized in that: The bio-enzyme microcapsules comprise: dissolving 1-2 parts of spirulina protein and 10 parts of uricase in a 0.1 mol / L phosphate buffer solution at pH 7.0 to prepare a uricase solution with a concentration of 20-30 mg / mL as the aqueous phase; dissolving polyurethane in dichloromethane to prepare an organic solution with a concentration of 50 mg / mL as the oil phase; mixing the oil phase volume to the aqueous phase volume at a high-speed shear rate of 10,000 rpm for 2 minutes to form a stable W / O promulgated emulsion; pouring the promulgated emulsion into 500 mL of an aqueous solution containing 1% by mass of polyvinyl alcohol, continuously stirring at 500 rpm, and evaporating in a 40°C water bath for 4 hours to solidify the microcapsule walls; centrifuging at 5000 rpm for 10 minutes to collect the solid, washing three times with deionized water, pre-freezing at -40°C, and freeze-drying under vacuum for 24 hours to obtain bio-enzyme microcapsules with a particle size of 50-200 micrometers.