A food residue culture medium and a method for propagating lignocellulose-degrading bacteria and applications thereof

Abstract

The present invention belongs to the technical field of composting. The food residue culture medium provided by the present invention comprises the following raw material components, measured by the volume of solvent water: 200-300 g / L of pomace, 100-150 g / L of bean dregs and 3-5 g / L of CaCO3; the pH value of the food residue culture medium is 6-7. The culture medium for expanding lignocellulose-degrading bacteria prepared from the food residue has low cost and is rich in sugars, proteins, fruit acids, vitamins and minerals. The food residues are fully utilized while solving the technical problems of high cost and low efficiency of conventional expansion methods of lignocellulose-degrading bacteria agents, and improving the xylanase activity, cellulase activity, laccase activity, manganese peroxidase activity and lignin peroxidase activity in the expanded product. The lignocellulose-degrading bacterial liquid obtained by expanding the food residue culture medium is applied to garden waste composting to improve the quality of compost.

Description

Technical Field

[0001] The invention belongs to the technical field of composting, and in particular relates to a food residue culture medium and a method for propagating lignocellulose-degrading bacteria and applications thereof. Background Art

[0002] The expansion of urbanization has resulted in the generation of a large amount of garden waste, mainly including dead branches and leaves, flowers and weeds, etc. Compared with traditional incineration, composting is an important means to achieve the harmlessness and resource utilization of garden solid waste. Garden waste has a high carbon-nitrogen ratio, large porosity, and low bulk density. These shortcomings can be solved by co-composting with another urban waste (kitchen waste). However, the degradation of lignocellulose is difficult during the co-composting process, which affects the composting fermentation rate. Therefore, how to accelerate the degradation of lignocellulose is the key to achieving efficient composting of garden waste.

[0003] Adding specific bacterial agents is an effective means to accelerate the degradation of lignocellulose during composting. At present, there have been many studies on bacterial agents for lignocellulose degradation, such as Chinese patent CN112725239A "A composting agent with cellulose degradation and deodorization function, its preparation method and application" and Chinese patent CN112195134A "Compound bacterial agent for cellulose degradation, its preparation method and application" both disclose the preparation method and application of lignocellulose degrading bacterial agents. However, the above patents usually use glucose, peptone, beef extract, corn pulp, etc. as carbon and nitrogen sources when carrying out bacterial strain expansion and cultivation, which makes the production cost of the bacterial agent too high, resulting in low production efficiency of the enterprise.

[0004] With the development of the food industry, a large amount of food residues are also produced. If they are discarded at will, they are likely to cause environmental pollution. At present, some scholars have carried out research on the expansion of composting bacteria with food processing waste. For example, Chinese patent CN1693450A "A method for preparing a culture medium for aerobic high-temperature composting fermentation functional bacteria" uses the waste liquid produced in the production process of soy products and glutamic acid as a matrix for bacterial expansion, but the waste liquid has high biochemical toxicity and is still not conducive to the growth of microorganisms. For example, Chinese patent CN112703967A discloses "A method for preparing liquid strains of wood-rotting fungi with yellow pulp water and bean dregs", and its culture medium components include corn flour, glucose, potassium dihydrogen phosphate, magnesium sulfate, vitamin B1, bean dregs and yellow pulp water; the culture medium components are complex and the cost is higher. Therefore, how to use food residues to carry out research on the expansion of composting bacteria has become an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a food residue culture medium and a method for propagating lignocellulose degrading bacteria and their application. The food residue culture medium is used for propagating lignocellulose degrading bacteria, so that food residues can be fully utilized while solving the technical problems of high cost and low efficiency of conventional propagation methods of lignocellulose degrading bacteria agents. At the same time, the lignocellulose degrading bacteria liquid obtained by propagating the food residue culture medium of the present invention can accelerate the degradation of lignocellulose in composting, realize efficient composting of garden waste and food waste, and can also increase the humic acid content and humification index, thereby improving the quality of compost.

[0006] In order to solve the above problems, the present invention provides the following technical solutions:

[0007] The present invention provides a food residue culture medium, which uses water as a solvent and comprises the following components in concentrations: 200-300 g / L of pomace, 100-150 g / L of bean dregs and 3-5 g / L of CaCO3;

[0008] The pH value of the food residue culture medium is 6-7.

[0009] The present invention also provides a method for propagating lignocellulose degrading bacteria, comprising the following steps: using the food residue culture medium described in the above technical solution to culture the seed liquid of lignocellulose degrading bacteria to obtain lignocellulose degrading bacterial liquid.

[0010] Preferably, the culture time is 2 to 3 days, the temperature is 35 to 50° C., and the rotation speed is 100 to 120 rpm.

[0011] Preferably, the lignocellulose degrading bacteria are Penicillium oxalicum and Aspergillus oryzae.

[0012] The present invention also provides the use of the lignocellulose degrading bacterial solution obtained by the above technical solution in composting, comprising: mixing the lignocellulose degrading bacterial solution with composting materials and performing aerobic fermentation for 35 to 42 days; the composting materials include garden waste and kitchen waste.

[0013] Preferably, the fresh weight ratio of the garden waste to the kitchen waste is 1 to 2:1.

[0014] Preferably, the moisture content of the compost material is 55-60%.

[0015] Preferably, the dosage ratio of the lignocellulose degrading bacterial solution to the compost material is (40-80) mL: 1 kg; the number of viable bacteria in the lignocellulose degrading bacterial solution is (3.2-4.1)×10 10 cfu / mL.

[0016] Preferably, the aerobic fermentation is carried out under aeration conditions, the gas supply rate is set to 0.02 L / min per kilogram of material on a dry weight basis, and the compost is turned and aerated on the 3rd, 7th, 14th, 21st, 28th and 35th days of fermentation.

[0017] Beneficial effects of the present invention: The food residue culture medium provided by the present invention includes pomace, bean dregs and CaCO3. The present invention generally uses pomace and bean dregs as raw materials, which reduces the pollution of the environment caused by the random discarding of pomace and bean dregs, and makes use of food residues. Pomace contains a large amount of residual sugar, while bean dregs are rich in protein, and the biochemical toxicity of the two is relatively low, so they can be used to replace traditional carbon and nitrogen sources such as glucose and peptone, becoming a good functional microbial culture substrate and reducing the culture cost; at the same time, pomace and bean dregs contain rich minerals, which can replace inorganic salt components such as potassium dihydrogen phosphate and magnesium sulfate; furthermore, pomace contains rich vitamins, which can replace B vitamins, and there is no need to add potassium dihydrogen phosphate, magnesium sulfate, B vitamins and other components, so the cost is low. Since pomace contains fruit acid and is prone to produce inorganic acid during the fermentation process, CaCO3 is used to adjust the pH value of the culture medium to prevent the pH from being too low during the fermentation process and inhibiting the reproduction and metabolism of microorganisms. At the same time, CaCO3 2+ It has the function of enhancing the acid resistance of mycelium and is more conducive to the growth and metabolism of microorganisms. In addition, the crude fiber content in fruit residues and bean residues is rich, which can stimulate the lignocellulose degrading bacteria to produce more enzymes and improve the efficiency of propagation. It can be seen that the food residue culture medium provided by the present invention can solve the problems of high cost and low efficiency of conventional propagation methods of lignocellulose degrading bacteria agents. DETAILED DESCRIPTION

[0018] The invention provides a food residue culture medium, which takes water as a solvent and comprises the following components in concentrations: 200-300 g / L of fruit residue, 100-150 g / L of bean dregs and 3-5 g / L of CaCO3.

[0019] The raw materials of the food residue culture medium provided by the present invention include 200-300 g / L of pomace, preferably 220-300 g / L, and more preferably 280 g / L, based on the volume of solvent water. In an embodiment of the present invention, the pomace in the food residue culture medium is preferably 300 g / L. In the present invention, the pomace preferably includes one or more of apple pomace, pear pomace, and grape pomace. The pomace contains a large amount of residual sugar, minerals, vitamins, and fruit acids, is rich in nutrients, has low biochemical toxicity, and is rich in crude fiber, which is beneficial to the growth and metabolism of microorganisms and can stimulate lignocellulose-degrading bacteria to produce more cellulase. The present invention has no special restrictions on the source of the pomace, and the pomace well known to those skilled in the art can be used.

[0020] Based on the volume of solvent water, the raw materials of the food residue culture medium provided by the present invention include 100-150g / L bean dregs, preferably 120-140g / L, and more preferably 130g / L. In an embodiment of the present invention, the bean dregs in the food residue culture medium are preferably 100g / L. Bean dregs are rich in protein, minerals, vitamins, fruit acids, rich in nutrients, low in biochemical toxicity, and rich in crude fiber content, which is suitable for the growth and metabolism of microorganisms and can stimulate lignocellulose degrading bacteria to produce more cellulase. The bean dregs of the present invention are preferably soybean dregs. The present invention has no special restrictions on the source of the soybean dregs, and the soybean dregs well known to those skilled in the art can be used. The nitrogen source of the single use of pomace culture is insufficient, and a large amount of organic acid will be produced when only pomace is used for microbial propagation, which will cause the pH of the culture medium to decrease and affect the growth efficiency of the microorganism. The present invention creatively mixes pomace and bean dregs together for preparation and culture. The soybean dregs have a high nitrogen content, which enriches the components of the culture medium and promotes the growth of lignocellulose degrading bacteria.

[0021] The raw material of the food waste culture medium provided by the present invention includes 3-5 g / L CaCO3, preferably 3.5-4.5 g / L, and more preferably 4.2 g / L, based on the volume of solvent water. In the embodiment of the present invention, the CaCO3 in the food waste culture medium is preferably 5 g / L. The function of the CaCO3 in the present invention is to adjust the pH value of the culture medium to prevent the pH from being too low during the fermentation process and inhibiting the reproduction and metabolism of microorganisms. At the same time, CaCO3 2+ The invention has no special restriction on the source of the CaCO3, and conventional commercially available CaCO3 can be used.

[0022] The pH value of the food residue culture medium is 6 to 7, preferably 6.2 to 6.8, and more preferably 6.5.

[0023] In the present invention, the method for preparing the food residue culture medium preferably comprises: mixing fruit residue, bean dregs, CaCO3 and water, and performing high temperature sterilization to obtain the food residue culture medium. In the present invention, the temperature of the high temperature sterilization is preferably 120-125°C, more preferably 121°C; the time of the high temperature sterilization is preferably 20-30 minutes, more preferably 25 minutes. The present invention has no special requirements on the source of water, and conventional tap water can be used. In an embodiment of the present invention, the water is preferably distilled water.

[0024] The present invention provides a method for propagating lignocellulose degrading bacteria, comprising the following steps: using the food residue culture medium described in the above technical solution to propagate the seed liquid of lignocellulose degrading bacteria to obtain lignocellulose degrading bacterial liquid.

[0025] In the present invention, the seed solution is preferably obtained by inoculating lignocellulose-degrading bacteria in a seed culture medium and culturing the same.

[0026] In the present invention, the lignocellulose degrading bacteria are preferably Penicilliumoxalicum and Aspergillusoryzae; the present invention has no special restrictions on the sources of Penicilliumoxalicum and Aspergillusoryzae, and conventional strains can be used. In the embodiment of the present invention, the Penicilliumoxalicum is preferably derived from the China Agricultural Microbiological Culture Collection Administration Center, with a collection number of ACCC32576; the Aspergillusoryzae is preferably derived from the China Agricultural Microbiological Culture Collection Administration Center, with a collection number of ACCC31491.

[0027] The present invention preferably inoculates Penicillium oxalicum into the seed culture medium for the first seed culture to prepare Penicillium oxalicum seed liquid; the present invention preferably inoculates Aspergillus oryzae into the seed culture medium for the second seed culture to prepare Aspergillus oryzae seed liquid; the time of the first seed culture and the second seed culture of the present invention is preferably 2 to 3 days, more preferably 3 days; the temperature of the first seed culture and the second seed culture is preferably 37 to 45°C, more preferably 40°C, and the rotation speed of the first seed culture and the second seed culture is preferably 100 to 120rpm, more preferably 100rpm. The number of viable bacteria in the seed liquid of the present invention preferably reaches 10 9 More than pcs / mL.

[0028] The seed culture medium described in the present invention is not particularly limited, and a seed culture medium familiar to those skilled in the art can be used, or the food residue culture medium described in the present invention can be used as the seed culture medium. The composition of the seed culture medium described in the present invention is preferably 1.5-2 g / L of yeast powder, 8-10 g / L of sucrose, 3-5 g / L of peptone, 1-1.2 g of dipotassium hydrogen phosphate and 0.3-0.5 g / L of magnesium sulfate, more preferably 2 g / L of yeast powder, 10 g / L of sucrose, 5 g / L of peptone, 1 g of dipotassium hydrogen phosphate and 0.5 g / L of magnesium sulfate; the time of the seed culture is preferably 2-3 days, more preferably 3 days; the temperature of the seed culture is preferably 37-45°C, more preferably 40°C, and the rotation speed of the seed culture is preferably 100-120 rpm, more preferably 100 rpm.

[0029] After obtaining the seed liquid of Penicillium oxalicum and the seed liquid of Aspergillus oryzae, the present invention preferably mixes the seed liquid of Penicillium oxalicum and the seed liquid of Aspergillus oryzae in a volume ratio of 1:1 to obtain a mixed seed liquid of Penicillium oxalicum and Aspergillus oryzae, and inoculates the mixed seed liquid of Penicillium oxalicum and Aspergillus oryzae into a culture medium for propagation of lignocellulose degrading bacteria to obtain a lignocellulose degrading bacterial liquid. The inoculation amount of the mixed seed liquid of Penicillium oxalicum and Aspergillus oryzae in the present invention is preferably 3% of the volume of the culture medium for propagation of lignocellulose degrading bacteria.

[0030] In the present invention, the time of the expansion culture is preferably 2 to 3 days, more preferably 3 days; the temperature of the expansion culture is preferably 37 to 45°C, more preferably 38 to 43°C, more preferably 40°C; the rotation speed of the expansion culture is preferably 100 to 120rpm, more preferably 100 to 110rpm, more preferably 100rpm.

[0031] The lignocellulose-degrading bacterial solution is obtained by propagation culture. The number of viable bacteria in the lignocellulose-degrading bacterial solution of the present invention is preferably (3.2-4.1)×10 10 cfu / mL, more preferably 3.7×10 10 cfu / mL.

[0032] The present invention provides an application of a lignocellulose-degrading bacterial solution in composting, comprising the following steps:

[0033] The lignocellulose degrading bacteria liquid and compost material are mixed and aerobic fermentation is carried out for 35 to 42 days; the compost material includes garden waste and kitchen waste.

[0034] The present invention mixes the lignocellulose degrading bacteria liquid and the compost material for fermentation. In the present invention, the lignocellulose degrading bacteria liquid is the lignocellulose degrading bacteria liquid obtained by the method for propagating lignocellulose degrading bacteria in the above technical solution. In the present invention, the compost material includes garden waste and kitchen waste. In the present invention, the particle size of the garden waste is preferably less than 5 cm; the present invention is preferably obtained by crushing. In the present invention, the fresh weight ratio of the garden waste to the kitchen waste is preferably 1 to 2:1, more preferably 1 to 1.5:1, and more preferably 1:1. In the present invention, the moisture content of the compost material is preferably 55 to 60%, more preferably 58 to 60%, and more preferably 59%. In the embodiment of the present invention, the moisture content of the compost material is preferably 60%. The present invention has no special restrictions on the types and sources of garden waste and kitchen waste, and the garden waste and kitchen waste known in the art can be used.

[0035] In the present invention, the usage ratio of the lignocellulose degrading bacterial solution to the compost material is preferably (40-80) mL:1 kg, more preferably (40-60) mL:1 kg, and more preferably 40 mL:1 kg.

[0036] In the present invention, the fermentation is aerobic fermentation; the time of the aerobic fermentation is preferably 35 to 42 days, more preferably 37 to 41 days, and more preferably 38 days; the temperature of the aerobic fermentation is preferably above 60°C. In the present invention, the aerobic fermentation is preferably carried out under ventilation conditions, and the air supply rate per kilogram of material on a dry weight basis is preferably 0.02L / min, and the compost is preferably turned on the 3rd, 7th, 14th, 21st, 28th, and 35th day of fermentation. The present invention preferably carries out aerobic fermentation in a composting fermentation tank; a fan is used to supply air at the bottom of the composting fermentation tank. The composting fermentation tank of the present invention is a 50L cylindrical closed device made of stainless steel, with an air inlet at the bottom, connected to the fan, and an air outlet at the top. The preferred compost product of the present invention is dark brown, and the compost is mature when there is no obvious odor, and the composting is finished.

[0037] The present invention utilizes the characteristics of high biodegradability and low toxicity of food residues, and uses food residues (fruit residues, bean dregs) as a culture matrix to propagate lignocellulose-degrading bacteria, thereby solving the problems of high cost and low efficiency of conventional propagation methods of lignocellulose-degrading bacteria agents. At the same time, the propagated products are used to accelerate the degradation of lignocellulose in the composting process of garden waste, thereby realizing the coordinated treatment and resource utilization of multi-source wastes and achieving the purpose of treating waste with waste.

[0038] In order to further illustrate the present invention, the food residue culture medium and applications provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0039] Example 1

[0040] (I) Raw material weighing preparation

[0041] Weigh the following components: 300 g apple pomace, 100 g soybean dregs, 5 g CaCO3, and 1 L distilled water.

[0042] (II) The method of using food residue culture medium to propagate lignocellulose-degrading bacteria is as follows:

[0043] 300 g of apple pomace, 100 g of soybean dregs, 5 g of CaCO3 and 1 L of distilled water were mixed and sterilized at 121° C. for 25 min to obtain a culture medium for propagating lignocellulose-degrading bacteria.

[0044] The prepared seed culture medium was divided into triangular bottles for sterilization at 121℃ for 25min. The composition of the seed culture medium was as follows: 2g / L yeast powder, 10g / L sucrose, 5g / L peptone, 1g potassium dihydrogen phosphate, and 0.5g / L magnesium sulfate. The lignocellulose-degrading fungus Penicillium oxalicum with the collection number of ACCC32576 was inoculated into the sterilized triangular flask and cultured in a shaking incubator at 40℃ and 100rpm for 72h to obtain the seed liquid of Penicillium oxalicum. The Aspergillus oryzae with the collection number of ACCC31491 was inoculated into the sterilized triangular flask and cultured in a shaking incubator at 40℃ and 100rpm for 72h to obtain the seed liquid. The total number of viable bacteria in the seed liquid of Penicillium oxalicum was 2×10 10 cfu / mL, the total viable count of Aspergillus oryzae seed solution was 2×10 10 cfu / mL.

[0045] The Aspergillus oryzae seed solution and the Penicillium oxalicum seed solution were mixed in a volume ratio of 1:1 to obtain a mixed seed solution of Penicillium oxalicum and Aspergillus oryzae. The total viable count of the two bacteria in the seed solution was 2×10 10 cfu / mL.

[0046] The mixed seed liquid of Penicillium oxalicum and Aspergillus oryzae was inoculated with 3% inoculum into the culture medium for propagation of lignocellulose degrading bacteria. The culture speed was 100 rpm, the temperature was 40°C, and the culture time was 72 hours. A lignocellulose degrading bacterial liquid containing Penicillium oxalicum and Aspergillus oryzae was obtained. The total number of viable bacteria of Penicillium oxalicum and Aspergillus oryzae in the lignocellulose degrading bacterial liquid was 3.7×10 10 cfu / mL.

[0047] Example 2

[0048] According to the method in Example 1, a lignocellulose-degrading bacterial solution is obtained and used for composting garden waste, and the steps are as follows:

[0049] Collect garden waste, mainly including some artificially pruned branches and naturally fallen branches and leaves; a mixture of garden waste branches and leaves in a ratio of 1:1 (fresh weight ratio) is crushed, and the particle size after crushing is <5cm.

[0050] 9 kg of the crushed garden waste was mixed with 9 kg of kitchen waste at a ratio of 1:1 (fresh weight ratio), and the moisture content was adjusted to 60% to obtain a compost material.

[0051] The lignocellulose degrading bacterial solution was evenly added to the compost material, and 40 mL of the lignocellulose degrading bacterial solution containing two kinds of bacteria, Penicillium oxalicum and Aspergillus oryzae, prepared in Example 1 was added per kg of the compost material;

[0052] The compost material added with lignocellulose degrading bacterial liquid is placed in a composting fermentation tank, and air is supplied by a fan at the bottom. The air supply rate is set to 0.02L / min per kilogram of material (dry weight). The compost is turned and aerated on the 3rd, 7th, 14th, 21st, 28th and 35th days. After 35 days, the compost product turns dark brown and has no obvious odor, indicating that the compost is mature and the composting is completed.

[0053] Comparative Example 1

[0054] The culture medium for the expansion of lignocellulose-degrading bacteria is Martin's medium, and other conditions are the same as those in Example 1.

[0055] Comparative Example 2

[0056] The food residue culture medium only contained pomace, and other conditions were the same as in Example 1.

[0057] Comparative Example 3

[0058] The food residue culture medium uses sodium hydroxide instead of calcium carbonate to adjust the pH value of the culture medium, and other conditions are the same as those in Example 1.

[0059] Comparative Example 4

[0060] The culture medium for propagating lignocellulose-degrading bacteria uses molasses commonly used in industry as a carbon source instead of pomace, and uses corn syrup as a nitrogen source instead of bean dregs. Other conditions are the same as those in Example 1.

[0061] Comparative Example 5

[0062] The lignocellulose degrading bacterial liquid obtained by propagating the lignocellulose degrading bacteria by the food residue culture medium of the present invention was not added, and other conditions were the same as those in Example 2.

[0063] Comparative Example 6

[0064] The lignocellulose degrading bacterial solution was uniformly added to the compost material. 20 mL of the lignocellulose degrading bacterial solution containing two kinds of bacteria, Penicillium oxalicum and Aspergillus oryzae, prepared in Example 1 was added per kg of the compost material. The rest was the same as in Example 2.

[0065] The viable bacterial count and xylanase activity, cellulase activity, laccase activity, manganese peroxidase activity, and lignin peroxidase activity of the lignocellulose degrading bacterial solution obtained in Example 1 and Comparative Examples 1 to 4 were measured. The viable bacterial count was determined by the plate count method. The specific method for determining the enzyme activity is as follows.

[0066] Determination of cellulase activity: Take 1mL of 1% sodium carboxymethyl cellulose solution, add 0.2mL of culture medium, and add 2.5mL of DNS reagent after 30min of 50℃ water bath. Boil in water bath for 5min, and measure the absorbance at 540nm after cooling. Cellulase activity is defined as the amount of 1ug of glucose produced per minute in 1mL of culture medium as one cellulase activity unit (U).

[0067] Xylanase activity assay: The xylanase activity assay procedure is the same as that of the cellulose enzyme activity assay, except that the substrate is a 1% xylan solution instead of a sodium carboxymethylcellulose solution. Xylanase activity is defined as the amount of 1 ug of glucose produced per minute in 1 mL of culture medium as one xylanase activity unit (U).

[0068] Determination of laccase activity: Use 0.6 mmol / L 3-ethylbenzothiazole-6-sulfonic acid (ABTS) as substrate, add 0.1 mL of culture medium, incubate in 30°C water bath for 1 min, and then measure the absorbance at 420 nm. The enzyme activity is defined as the amount of ABTS degraded by 1 mL of culture medium per minute, which is one laccase activity unit (U).

[0069] Manganese peroxidase activity determination: Take 10 mmol / L manganese sulfate as substrate, add 0.1 mL culture medium and 0.01 mL hydrogen peroxide (10 mmol / L), and measure the absorbance at 270 nm after 1 min in a 30°C water bath. The enzyme activity is defined as the amount of manganese sulfate degraded by 1 umol of 1 mL culture medium per minute as one laccase activity unit (U).

[0070] Lignin catalase activity determination: 40mmol / L resveratrol was used as substrate, 0.1mL culture medium and 0.01mL hydrogen peroxide (20mmol / L) were added, and the absorbance was measured at 310nm after 1min in a 30℃ water bath. The enzyme activity was defined as the amount of resveratrol degraded by 1umol per minute in 1mL culture medium as one laccase activity unit (U).

[0071] The measurement results are shown in Table 1.

[0072] Table 1 Data on viable bacterial count and enzyme activity of lignocellulose-degrading bacterial solution after 72 h of culture (n=3)

[0073]

[0074] Note: Different lowercase letters indicate significant differences among treatments (P<0.05).

[0075] As can be seen from Table 1, the lignocellulose degrading bacteria liquid obtained by using food residue culture medium as the propagation culture medium for lignocellulose degrading bacteria in the present invention is compared with the lignocellulose degrading bacteria liquid obtained by using Martin's culture medium as the propagation culture medium for lignocellulose degrading bacteria. The number of viable bacteria, xylanase activity, cellulase activity, laccase activity, manganese peroxidase activity and lignin peroxidase activity of the lignocellulose degrading bacteria liquid obtained by using food residue culture medium in the present invention are significantly improved.

[0076] The total viable count of the two bacteria in Example 1 was 3.70×10 10 cfu / mL, which is significantly improved compared with Comparative Example 1, Comparative Example 3, Comparative Example 4, and Comparative Example 5; the xylanase activity, cellulase activity, laccase activity, manganese peroxidase activity, and lignin peroxidase activity of Example 1 are significantly improved compared with those of Comparative Example 1, Comparative Example 3, Comparative Example 4, and Comparative Example 5.

[0077] After the garden waste obtained in Example 2 and Comparative Examples 5 to 6 was composted, the organic matter content, hemicellulose degradation rate, cellulose degradation rate, lignin degradation rate, total lignocellulose degradation rate, humic acid content, and humification index of the compost product were measured. The test method is as follows:

[0078] The organic matter content of compost products was determined by the 550°C calcination method. The dried compost sample was crushed and passed through a 40-mesh sieve and calcined in a muffle furnace at 550°C for 4 hours. The calcined part was organic matter and the remaining part was ash.

[0079] Lignocellulose = cellulose + hemicellulose + lignin

[0080] Determination of acid detergent lignin (ADL) in feed according to national standard GB / T20805-2006, determination of neutral detergent fiber (NDF) in feed according to national standard GB / T20806-2006 and determination of acid detergent fiber in feed according to industry standard NY / T1459-2007;

[0081] Hemicellulose = neutral detergent fiber-acid detergent fiber;

[0082] Cellulose = acid detergent fiber - acid detergent lignin

[0083] Lignin = acid washed lignin - ash

[0084] Lignocellulose degradation rate (%) = (initial lignocellulose amount - final lignocellulose amount) / initial lignocellulose amount;

[0085] Cellulose degradation rate (%) = (initial cellulose amount - final cellulose amount) / initial cellulose amount;

[0086] Hemicellulose degradation rate (%) = (initial hemicellulose amount - final hemicellulose amount) / initial hemicellulose amount;

[0087] Total lignocellulose degradation rate (%) = (initial total lignocellulose content - final lignocellulose content) / initial total lignocellulose content, where total lignocellulose content = cellulose + hemicellulose + lignin;

[0088] The humic acid content is determined according to the industry standard: NY-T1971-2010 Determination of humic acid content in water-soluble fertilizers;

[0089] Humic acid content / total organic matter content.

[0090] Table 2 Changes in organic matter components after composting (n=3)

[0091]

[0092] Note: Different lowercase letters indicate significant differences among treatments (P<0.05).

[0093] According to Table 2, the lignocellulose degrading bacterial liquid obtained in Example 1 was uniformly added to the garden waste compost material. The cellulose degradation rate, lignin degradation rate, total lignocellulose degradation rate, humic acid content and humification index of Example 2 after composting were all improved. Compared with Comparative Example 5, the cellulose degradation rate was increased by 12.6%, the lignin degradation rate was increased by 38.1%, the total lignocellulose degradation rate was increased by 9.2%, the humic acid content was increased by 24.9%, and the humification index was increased by 21.8%, which effectively improved the quality of the compost product. Compared with Comparative Example 6, the organic matter content, hemicellulose degradation rate, cellulose degradation rate, lignin degradation rate, total lignocellulose degradation rate, humic acid content and humification index of the compost product of Example 2 were also improved to a certain extent.

[0094] In summary, the food residue culture medium and the method for propagating lignocellulose degrading bacteria provided by the present invention increase the bacterial viability and xylanase activity, cellulase activity, laccase activity, manganese peroxidase activity, and lignin peroxidase activity of the lignocellulose degrading bacteria liquid. The lignocellulose degrading bacteria liquid obtained by propagating the food residue culture medium of the present invention is added to the garden waste compost, which effectively improves the quality of the compost.

[0095] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A food residue culture medium for propagating lignocellulose-degrading bacteria, characterized in that: Using water as solvent, it is composed of the following components at the following concentrations: apple pomace 200-300 g / L, bean dregs 100-150 g / L, and CaCO3 3-5 g / L; The pH value of the food residue culture medium is 6-7.

2. A method for propagating lignocellulose-degrading bacteria, characterized in that: The following steps are involved: The food residue culture medium of claim 1 is used to culture the seed liquid of lignocellulose degrading bacteria to obtain lignocellulose degrading bacterial liquid; the lignocellulose degrading bacteria is Penicillium oxalicum ( Penicillium oxalicum ) and Aspergillus oryzae ( Aspergillus oryzae ).

3. The method according to claim 2, characterized in that The culture time is 2 to 3 days, the temperature is 35 to 50° C., and the rotation speed is 100 to 120 rpm.

4. The method according to claim 2 or 3, characterized in that: The culture temperature was 40°C.

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