219 results about "Acidogenesis" patented technology

The invention belongs to the technical field of wastewater treatment and energy recovery, and provides a regulation and control method for promoting anaerobic acid production by taking soybean molasses as a substrate through cooperation of ferroferric oxide and bamboo charcoal. Soybean molasses is used as a substrate carbon source, anaerobic activated sludge is inoculated in a medium-temperature SBR reactor, the volume ratio of reactor inflow sewage to sludge is 2: 1, ferroferric oxide and bamboo charcoal composite conductive particles which are subjected to ball milling treatment and have the concentration of 1 g / L are added to promote an anaerobic fermentation system to produce acid, and then anaerobic fermentation is carried out. The mass ratio of ferroferric oxide to bamboo charcoal in the ferroferric oxide and bamboo charcoal composite conductive particles is (1: 2)-(2: 1); monitoring the acid yield, the pH value change and the product type; and the variety and concentration of the acid-producing substance are analyzed, and the interaction of all the components in the reaction process is evaluated. The acid production rate and the total acid production amount in the anaerobic acid production process are obviously improved. And the activity of anaerobic flora is promoted. The variety distribution of acid-producing substances is obviously optimized, and the stability of the acidification process is improved.

The invention relates to the technical field of microorganisms, in particular to a strain of Lactiplanilla pentosuses ZF634 and application of the strain of Lactiplanilla pentosuses ZF634 and the application of the strain of Lactiplanilla pentosuses ZF634. The lactobacillus pentosus strain ZF634 is obtained through screening and still has efficient acid production capacity in a bean-based culture medium, and the bean curd coagulator prepared from fermentation liquor of the lactobacillus pentosus strain ZF634 has the function of enhancing aroma and flavor; the beany flavor of the prepared sour slurry bean curd is obviously reduced, and the sour slurry bean curd also has special milk flavor; the protein hydrolysis degree and flavor precursor substance accumulation of the prepared fermented bean curd embryo are far superior to those of a commercial sour slurry water sample, the content of fresh and sweet amino acids and organic acids is remarkably increased, the fresh and sweet taste of the fermented bean curd is improved, the taste is softer and more harmonious, the sensory quality of the final product is broken through, and the aroma, the taste and the texture are remarkably improved.

The invention relates to the technical field of wastewater treatment or water quality purification, in particular to a method for synchronously culturing ammonia oxidizing bacteria and nitrite oxidizing bacteria, which comprises the following steps: selecting an inorganic material which is large in specific surface area and can quickly neutralize and release alkalinity as a nitrifying bacteria attachment carrier and an alkalinity supplement / pH regulator; the carrier is dissolved through nitration acid production, carbon dioxide and alkalinity are released, a carbon source and alkalinity required by growth are provided for nitrifying bacteria, and propagation of the nitrifying bacteria is promoted. Ammonia oxidizing bacteria and nitrite oxidizing bacteria are cultured synchronously by controlling the growth speed of the two bacteria in the culture process. By controlling the ammonia nitrogen concentration and nitrite concentration of the effluent at the end of culture to be lower than 50mg / L, sufficient time is provided for nitrite oxidizing bacteria to decompose an intermediate product nitrite, so that the purpose of simultaneously culturing AOB and NOB is achieved.

The invention discloses a urease-producing microorganism induced calcium carbonate deposition solution for foundation reinforcement and a preparation method and application thereof, and belongs to the technical field of foundation reinforcement. The urease-producing microorganism induced calcium carbonate deposition solution comprises a bacterial solution, a cementing solution and a sodium citrate solution, the bacterial liquid comprises bacteria capable of generating urease and citrobacter freundii. Sodium citrate in the urease-producing microorganism induced calcium carbonate deposition solution can chelate free calcium ions in advance, the concentration of the free calcium ions is reduced, the risk of precipitation at an injection port in the single-phase injection process is eliminated, and the solution can smoothly permeate into a deep layer; citrobacter freundii produces acid through metabolism and utilizes citric acid radicals through metabolism to ensure gradual release of calcium ions, so that uniform deposition of calcium carbonate is triggered. Through the synergistic effect of sodium citrate chelated calcium ions and citrobacter freundii metabolism, the solution can be uniformly distributed in the soil sample, and the problem of uniformity of single-phase perfusion is successfully solved.

The invention discloses a system for producing short-chain volatile fatty acid through kitchen co-fermentation of sludge, and relates to the technical field of biochemical engineering and environmental engineering. Comprising a time phase construction module, a causal playback identification module, a flow field mapping correction module, a metabolism gating feedback module, a structure reconstruction steady-state module and a phase traction control module, and reconstructing a gas-liquid phase difference reference surface according to the real-time flow field response, and establishing a reference surface to calibrate an anti-phase trigger window. According to the method, gas-liquid reverse-phase accurate identification is realized through a high-precision time base line and flow field tracking, a causal chain is constructed to early warn an inverted nucleation area in advance, a steady-state energy base plane is established in combination with three-dimensional flow field correction and metabolism monitoring feedback and driving structure cooperative adjustment, and finally disturbance suppression and path self-resetting are realized through phase traction regulation. The acid production efficiency and the system stability are improved.

The invention provides a preparation method of a compound microbial agent and a pasture fermented feed, and belongs to the technical field of feed fermentation. The complex microbial inoculant disclosed by the invention comprises lactobacillus acidophilus, bacillus siamensis, bacillus amyloliquefaciens and pichia kluyveri. The lactobacillus acidophilus can produce acid and resist acid, and has better antibacterial performance; the bacillus siamensis can degrade lignin and reduce the content of neutral detergent fibers and acid detergent fibers in the fermented feed; the bacillus amyloliquefaciens produces cellulase and amylase with higher activity; the pichia kluyveri can increase the content of crude protein in the fermented feed and improve the nutritional performance of the feed. The four strains have a synergistic effect and jointly ferment forage feed, infectious microbes can be effectively inhibited, the fermented forage feed has excellent color, smell and texture, the palatability of the feed is improved, the appetite of animals is stimulated, and a good growth promoting effect is achieved; the fermented forage feed disclosed by the invention is high in nutritional quality and relatively high in feed utilization rate.

The invention provides a strain for producing L-2-aminobutyric acid as well as a construction method and application of the strain. According to the strain, E.coli W3110 is taken as a chassis strain, tdh, rhtA and ilvE genes are knocked out, the transcriptional levels of ppc, aspC, thrAfbrBC, ilvAfbr, tdcB, yaS and pntAB genes are up-regulated, an ilvI gene is weakened, bcd and gdh genes derived from bacillus subtilis B.subtilis 168 and a cysK gene derived from Corynebacterium glutamicum K051 are introduced in a heterologous manner, and the L-2-aminobutyric acid producing strain is obtained through screening and screening. The strain does not contain plasmids, is stable in heredity, does not need induction, does not need to add resistant substances, efficiently synthesizes L-2-aminobutyric acid from the beginning by taking glucose as a substrate, and has good L-2-aminobutyric acid synthesis capability, stable performance and high acid production efficiency.

The invention relates to the technical field of probiotic development and utilization, in particular to a goose source Weissella cibaria F11 and application thereof. The Weissella cibarius F11 is preserved in the China General Microbiological Culture Collection Center on July 11, 2025, and the preservation number is CGMCC NO.35211. The Weissella cibarius F11 has the characteristics of good acid resistance and cholate resistance, and can be used for preparing the acid-resistant and cholate-resistant strain. And the bacillus subtilis has a good inhibition effect on pathogenic bacteria such as escherichia coli, pseudomonas aeruginosa, staphylococcus aureus and salmonella typhimurium, and also has stable acid production capacity and good safety. The Weissella sinus F11 provided by the invention meets the probiotic characteristic standard, the antibiotic resistance spectrum of the Weissella sinus F11 meets the feed probiotic safety standard, the growth of goslings can be remarkably promoted, the death rate and diarrhea occurrence rate of the goslings can be remarkably reduced, and the weissella sinus F11 can be used for preparing feed probiotics. The development potential in the fields of preparation of bacteriostatic and antibacterial drugs, probiotics for poultry feed, feed additives, poultry feed and the like is huge.

Provided in the present application is a method for treating a heavy bis(fluorosulfonyl)imide residue, comprising the following step: causing a starting material system comprising the heavy bis(fluorosulfonyl)imide residue and an acidic aqueous solution to react to obtain a fluorine-containing acid solution and a crude sulfamic acid product, wherein the fluorine-containing acid solution can be used as a by-product acid, thereby saving treatment costs; and the crude sulfamic acid product can also be directly sold as a product, thereby reducing treatment costs, bringing economic benefits, and achieving resource recycling of the heavy bis(fluorosulfonyl)imide residue.

The application provides a pediococcus acidilactici M4 for low-moisture fermented feed and an application thereof, and belongs to the field of microbial application and feed technology. The application uses the pediococcus acidilactici M4 to prepare fermented total mixed ration. The bacteria have the characteristics of high osmosis and fast acid production, and can reduce the pH value of the fermentation system in a short time; have strong broad-spectrum bacteriostatic effect on escherichia coli, chicken white dysentery salmonella and staphylococcus aureus; and perfectly adapt to the fermentation of low-moisture total mixed ration. The strain is used as the fermentation strain of low-moisture total mixed ration, can significantly reduce the content of acid detergent fiber and neutral detergent fiber, improve the crude protein level, and then improve the digestibility of the daily ration, increase the content of probiotics such as lactic acid bacteria and yeast in the daily ration, reduce the content of pathogenic bacteria such as escherichia coli in the daily ration, and also can improve the content of volatile fatty acid in the daily ration, improve the quality of the daily ration, and improve the feeding value of the daily ration.

The application relates to the field of genetic engineering, and discloses an Aspergillus niger, a construction method and application of the Aspergillus niger, and a method for producing citric acid and / or succinic acid. Aspergillus niger The Aspergillus niger is obtained by simultaneously overexpressing alpha-amylase and aspartic protease in a starting strain. The Aspergillus niger provided by the application can realize efficient degradation and conversion of starch by synergistically overexpressing amyA genes and pepA genes, solve the technical bottleneck that the original strain is limited in growth in a starch-based fermentation system and has insufficient acid production capacity, can efficiently produce succinic acid and citric acid by taking low-cost starch as the only carbon source, significantly reduce the industrial production cost of organic acid, and promote the green and sustainable upgrading of the fermentation industry.

The application discloses a production process for preparing composite carbon source by utilizing fruit and vegetable waste resources, and comprises the following steps: raw material pretreatment, anaerobic fermentation for acid production, composite enzymolysis, deep solid-liquid separation, composite blending, and stabilization treatment; the blending carbon source liquid is pumped into the stabilization treatment tank, 0.1%-0.3% of a compounded stabilizer is added, the pH value is adjusted to 6.0-7.0, normal-temperature standing is carried out for 12-24 hours, product detection and storage are carried out, the carbon source product after the stabilization treatment is detected in terms of COD, total nitrogen, total phosphorus, the pH value and the content of small-molecule organic acid, and after each index is qualified, the product is sealed and packaged and stored in a cool and dry environment, and the application solves the technical problems of high cost, poor safety, single fruit and vegetable base carbon source component, low degradation efficiency and poor product stability of traditional carbon sources.

The invention discloses lactobacillus helveticus 5-1 separated from fermented milk and application of the lactobacillus helveticus 5-1. The lactobacillus helveticus 5-1 has the highest viable count in 12 hours at the end of the logarithmic phase; the lactobacillus helveticus 5-1 has better acid production capacity and acid resistance; the tolerance of the lactobacillus helveticus 5-1 is strong under the bile salt concentration of 0.3%; the thallus extract of the lactobacillus helveticus 5-1 has strong capability of removing DPPH (1, 1-diphenyl-2-picrylhydrazyl); the lactobacillus helveticus 5-1 is high in exopolysaccharide (EPS) production capacity. The lactobacillus helveticus 5-1 with high activity, strong oxidation resistance, excellent acid and cholate resistance and high exopolysaccharide yield is separated, screened and cultured from the traditional fermented milk in Xinjiang, so that the blank of multifunctional and high-performance autonomous strains in the prior art is filled; the application efficiency and the stability of the compound in probiotic preparations and functional foods are improved.

The invention provides a method for treating bis (fluorosulfonyl) imide heavy slag, which comprises the following steps: reacting a raw material system comprising bis (fluorosulfonyl) imide heavy slag and an acidic aqueous solution to obtain a fluorine-containing acid solution and a sulfamic acid crude product; wherein the fluorine-containing acid liquid can be used as a byproduct acid, so that the treatment cost is saved; and the sulfamic acid crude product can also be directly sold as a product, so that the treatment cost is reduced, economic benefits are brought, and resource recycling of the bis (fluorosulfonyl) imide heavy slag is realized.

The application belongs to the technical field of microorganisms, and particularly relates to a halophilic bacillus, a bacterial agent and application thereof. The application provides a halophilic bacillus Halobacillus andaensis, and the preservation number is CCTCC M 20232394. The application also provides a bacterial agent containing the halophilic bacillus. The application also provides application of the halophilic bacillus or the bacterial agent in promoting plant growth under saline-alkali stress, improving plant stress resistance, improving soil, and crop production. The halophilic bacillus provided by the application has excellent saline-alkali tolerance, and can only grow under saline-alkali conditions. Meanwhile, the halophilic bacillus has growth-promoting characteristics such as salt reduction, acid production for alkali reduction, nitrogen fixation, and the like, can reduce salt damage, and improve crop yield and quality.

This invention provides a method for the co-production of organic acids and lignin from lignocellulose, comprising the following steps: Step 1, pretreating the lignocellulose raw material to obtain a pretreated material; Step 2, enzymatically hydrolyzing the pretreated material to obtain an enzymatic hydrolysate containing pentoses, hexoses, and lignin; Step 3, performing solid-liquid separation on the enzymatic hydrolysate to obtain an enzymatic hydrolysate containing pentoses and hexoses and a solid phase containing lignin; Step 4, subjecting the enzymatic hydrolysate containing pentoses and hexoses to acid-producing fermentation to obtain a fermentation broth containing a mixture of organic acids; Step 5, extracting lignin from the lignin-containing solid phase to obtain lignin. The method provided by this invention can efficiently separate lignin and obtain various organic acids through a simple process.

The invention relates to a method for breeding chrysomyia megacephala larvae based on a complex microbial inoculant fermented feed, and belongs to the technical field of chrysomyia megacephala larva breeding. The action time of different strains is regulated and controlled by preparing the microcapsules to wrap the complex microbial inoculants, in the anaerobic environment at the initial stage of fermentation, lactic acid bacteria can produce a large amount of acid to inhibit growth of pathogenic bacteria and putrefying bacteria, at the moment, the microcapsules can effectively protect the complex microbial inoculants wrapped in the microcapsules from being damaged by the low-pH environment, and the complex microbial inoculants can be effectively prevented from being damaged by the low-pH environment along with continuous fermentation. The lactic acid bacteria break the microcapsule structure and slowly release the complex microbial inoculant to preempt the ecological niche in the material, the breeding method can enable different microbial inoculants to play a role in respective adaptive environments, the action efficiency of the complex microbial inoculant is effectively improved, and generation of harmful gas is reduced.

The invention discloses a process and a device for producing acid by coupling chemical enhanced membrane grid filtration with anaerobic fermentation, and belongs to the technical field of sewage treatment. The method comprises the following steps: enabling effluent of an aerated grit chamber of a municipal sewage treatment plant to pass through a reaction tank consisting of a coagulation tank and a flocculation tank, a filter tank and an anaerobic fermentation tank, and feeding obtained filtrate and mixed liquid into a biochemical tank for biological denitrification. The device adopting the process is used as a pretreatment process unit for biological denitrification of a biochemical pool, on one hand, the concentration of soluble COD (Chemical Oxygen Demand) in influent water of the biochemical pool can be improved, the total nitrogen removal effect can be further improved, the total nitrogen of effluent can be reduced by 2-4mg / L, and optimal preparation of resources is realized, and on the other hand, the process and the device can completely or partially replace an external carbon source, so that the environmental pollution is reduced. And considerable economic benefits are generated.

An Acidaminococcus fermentans strain and use thereof in improving rumen fermentation are provided, and relates to the technical field of microorganisms. An acid-producing strain of Acidaminococcus fermentans P47 is obtained by screening, which has desirable passage stability and safety. The strain can increase a ratio of butyric acid in the rumen of a ruminant, improve rumen fermentation parameters of a pre-weaning calf, promote rumen fermentation, improve a rumen environment, and increase an average daily gain (ADG) of the ruminant.

The invention provides a method and a system for evaluating acetic acid production capacity of strong-flavor Daqu, and relates to the technical field of microbial function analys.The method comprises the steps of obtaining kinetic parameters of the acetic acid production capacity of a main stress response stage representing the upper limit of the Daqu acid production capacity through pulse injection of gaseous ethanol, and then conducting pulse injection of atomized lactic acid serving as a metabolism perturbator to obtain the acetic acid production capacity of the Daqu. Obtaining kinetic parameters representing the acetic acid production capacity of the microbial system under external pressure in a metabolic disturbance recovery stage, and evaluating the acetic acid production capacity of the Luzhou-flavor Daqu based on the kinetic parameters of the acetic acid production capacity in the main stress response stage and the kinetic parameters of the acetic acid production capacity in the metabolic disturbance recovery stage. The method solves the problem of low efficiency of evaluating the acetic acid production capacity of the existing strong-flavor Daqu, and is suitable for evaluating the acetic acid production capacity of the Daqu.

The present application belongs to the field of biomass anaerobic digestion, and provides a two-phase integrated anaerobic digestion and exogenous particle recycling device.The device comprises a main reactor, an online liquid level control system, a gas collection system and a gas backflow stirring system, and the main reactor contains a hydrolysis acidification zone, an acid production buffer zone and a methane production zone.The hydrolysis acidification zone is provided with a hydrolysis acidification chamber, a stirring device, a hydrolysis acidification chamber sample discharge port and a sample inlet.The acid production buffer zone comprises an acid production buffer chamber and an improved three-way valve.The methane production zone comprises a methane production chamber sample discharge port, a gas distribution device, a methane production chamber, a PVC connecting pipe, a particle settling zone, an overflow sample discharge port, a partition, a particle settling zone sample discharge port, a baffle and a sludge discharge port.The two-phase integrated anaerobic digester in the present application separates the hydrolysis acidification zone and the methane production zone through an upper and lower layered anaerobic digestion tank, which is conducive to improving the organic load and volumetric gas production rate of the system, and the reactor structure is compact, reducing the floor area.

The invention discloses a preparation method and application of an electrode of bioelectrochemical equipment. The method comprises the following steps: S1, pretreatment; s2, preparing a polyvinyl alcohol solution; s3, preparing electrode slurry; s4, coating is carried out; and S5, drying. The electrode is used for treating chlorophenol wastewater. The electrode provided by the invention is prepared by modifying zero-valent iron, is arranged in an anode region of a bioelectrochemical reactor, and can effectively regulate and control oxidation-reduction potential, strengthen electron transfer between iron reducing bacteria and acetogenic bacteria at an anode and enrich acetogenic flora by loading trace zero-valent iron, so that the yield of acetic acid in an acidogenic phase is increased; the synchronous pollutant removal and methane yield increase are realized, and the economic benefit is improved.

This invention belongs to the fields of fermentation and genetic engineering technology, and provides a high-yield hexanoic acid-producing engineered *Escherichia coli* strain, its construction method, and its applications. This engineered strain is *Escherichia coli*... E. coli w3110 was the starting strain, overexpressing the acetyl-CoA transferase gene. act and β-ketothiolase gene bktB Overexpression of trans-enoyl-CoA reductase gene ter 3-Hydroxybutyryl-CoA dehydrogenase gene hbd, and 3-hydroxybutyryl coenzyme A dehydratase gene crt Or, simultaneously not expressing the pyruvate formate lyase gene. pflB or lactate dehydrogenase gene ldhA This engineered bacteria can convert glucose into hexanoic acid, a high-value product, with a yield of 4.968 g / L after 18 hours of fermentation. It adopts aerobic fermentation, resulting in rapid cell growth, a short fermentation cycle, and a high acid production rate. The fermentation process is simple, easy to control, and has low production costs, which is conducive to its promotion and application in industrial production.

The invention belongs to the technical field of fermented tea beverages, and particularly discloses compound fermented Kangpu tea as well as a preparation method and application thereof. According to the compound fermented Kangpu tea, black tea water is inoculated with compound bacteria for fermentation, the compound bacteria are composed of foal bacillus medialis, saccharomyces cerevisiae and sake lactobacillus, the mass ratio of the foal bacillus medialis to the saccharomyces cerevisiae to the sake lactobacillus is 2: 2: (1-2), the preservation number of the foal bacillus medialis is WDCM No. JCM 16936, the preservation number of the saccharomyces cerevisiae is CGMCC No. 2.3973, and the preservation number of the sake lactobacillus is CGMCC No. 2.3973. The sake lactobacillus is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.34016. Compared with single-bacterium or two-bacterium composite inoculated fermentation, the growth activity, the acid production capacity and the reducing sugar consumption capacity of the Kangpu tea are better, the content of flavor substances such as aldehydes and esters is improved through the GC-IMS technology, and the flavor quality of the Kangpu tea is improved.

The invention provides a saline-alkali-resistant soil conditioner and application, and belongs to the technical field of agricultural planting. The invention provides a complex microbial inoculant mainly composed of Staphylococcus xylosus and Aspergillus niger, and the two strains have acid production capability. After the complex microbial inoculant is added into the saline-alkali soil, the pH and EC of the soil can be obviously reduced, and the growth and development of crops are promoted. According to the invention, the complex microbial inoculant is compounded with other components to prepare a microbial preparation, and then the microbial preparation is loaded by a carrier to prepare a carrier preparation. After the carrier preparation prepared by the invention is applied to the saline-alkali soil, the biomass of crops planted on the saline-alkali soil can be remarkably improved, the yield and the quality are improved, the soil is investigated after the crops are harvested, and the soil is found to be remarkably improved in organic matter and total nitrogen content and reduced in pH value and total salt content.

The present application relates to the field of agricultural microorganism technology, and discloses a strain of starch-degrading Levilactobacillus brevis AM515, which has a preservation number of CGMCC No. 33115, and the strain can have a degradation or structural modification capacity on corn starch in an anaerobic silage fermentation environment with a pH of 3.5-4.2. Development and application of a strain of Levilactobacillus brevis for improving in-vitro digestibility of whole-plant corn silage starch, the provided Levilactobacillus brevis AM515 (CGMCC No. 33115) is a functional strain directly screened from a silage environment. It can not only produce acid quickly like traditional lactic acid bacteria and dominate silage fermentation, but also has the ability to survive stably in a harsh low-pH (3.5-4.2) and anaerobic silage environment, degrade the starch content in corn silage feed, and improve the in-vitro digestibility of starch. This overcomes the dual technical obstacles of the difficulty of ordinary starch-degrading bacteria to adapt to the silage environment and the insufficient starch capacity of traditional silage lactic acid bacteria.

This invention relates to the field of biotechnology, specifically disclosing a freeze-drying protection system for Enterococcus faecalis, its preparation method, and its applications. The freeze-drying protection system comprises arginine, skim milk, and glycerol, combined with low-temperature stress pretreatment. The freeze-drying protection system provided by this invention significantly increases the freeze-drying survival rate of Enterococcus faecalis L118 to 87.90±1.28%, and the survival rate remains above 90% after 28 days of storage at -20℃. The core probiotic characteristics of the freeze-dried Enterococcus faecalis L118 strain, such as acid production capacity, simulated gastric juice, and NaCl tolerance, are well preserved, providing an effective solution for preparing highly active and stable Enterococcus faecalis preparations.

The screening method comprises the following steps: S1, taking a high-temperature yeast sample, adding sterile normal saline, soaking and oscillating, taking supernate, inoculating the supernate into an acetic acid bacteria enrichment culture medium, and culturing at constant temperature to obtain enriched liquid; s2, carrying out gradient dilution on the enrichment liquid, taking a diluent with a proper concentration, coating a calcium plate isolation culture medium with the diluent, and selecting a single colony generating a transparent circle to carry out multi-generation streak purification; s3, inoculating the purified strain to an acidogenic qualitative culture medium, carrying out shake cultivation, centrifuging the fermentation broth, taking the supernatant, neutralizing the supernatant with a NaOH solution until the pH value is 7, adding a FeCl3 solution, and heating in a boiling water bath to generate a rufous flocculent precipitate which is an acidogenic bacterium; and S4, preparing bacterial suspension from the bacterial strains which are qualitatively identified as acid-producing bacteria, inoculating the bacterial suspension to a basic culture medium, and selecting the bacterial strain with the highest acid yield as a target bacterial strain. The strain with high acid yield and high stress tolerance obtained by screening provides a high-quality microbial resource for improving the quality of Maotai-flavor liquor.

The invention belongs to the field of microbial agents, and particularly relates to a compound microbial agent and application thereof.Activated bacillus subtilis SL-44 and klebsiella oxytoca Rs-5 are subjected to amplification culture, a bacillus subtilis SL-44 fermentation liquor and a klebsiella oxytoca Rs-5 fermentation liquor are obtained, the fermentation liquor is added into the fermentation liquor, the fermentation liquor is added into the fermentation liquor, the fermentation liquor is added into the fermentation liquor, and the fermentation liquor is added into the fermentation liquor to prepare the compound microbial agent. And carrying out mixed fermentation culture on the bacillus subtilis SL-44 fermentation liquor and the klebsiella oxytoca Rs-5 fermentation liquor to obtain the compound microbial agent. The compound microbial agent has the capabilities of producing siderophore, dissolving phosphorus, producing indoleacetic acid, producing 1-aminocyclopropane-1-carboxylic acid deaminase and producing a biological membrane, and can remarkably promote the germination of plant seedlings, increase the plant biomass, improve the stress resistance of plants and improve the appearance and internal quality of plant fruits.

The application discloses an application of astragalus polysaccharide in promoting lactic acid bacteria metabolism and improving quality and stability of fermented products, and belongs to the technical field of fermented dairy product processing. The application adds 2 ‰ to 10 ‰ of astragalus polysaccharide and sucrose in skimmed milk with respect to the mass of the skimmed milk, inoculates lactic acid bacteria starter after pasteurization, and constant-temperature fermentation is carried out until the end point to prepare fermented products. The application utilizes the dual functions of astragalus polysaccharide in promoting lactic acid bacteria metabolism and strengthening milk protein gel network to realize the synergistic improvement of quality and stability of fermented products. Experiments show that when the addition amount of astragalus polysaccharide is 4 ‰, the sensory score of the fermented product reaches 87.3, and the water holding capacity is increased by 11.95 % compared with the control group; scanning electron microscopy shows that the gel network is dense and has few pores; when the addition amount is 6 ‰, the viable cell count reaches 1.23 x 10 8 CFU / ml; and when the addition amount is 8 ‰, the texture characteristics are optimal. The application is simple in operation, suitable for industrial production, and provides a new way for the development of functional fermented dairy products.