Composite lignin degrading fungus, fermentation culture method, application and straw feed

Abstract

The invention belongs to the technical field of lignin degradation, and discloses a composite lignin degrading fungus, a fermentation culture method, application and straw feed, the composite lignin degrading fungus, Irpex lacteus and Trametes versicolor are included, and the weight ratio of Irpex lacteus to Trametes versicolor is (1-2): (1-2). According to the composite lignin degrading fungus provided by the invention, Irpex lacteus and Trametes versicolor are adopted to form a composite strain, and when the Irpex lacteus and the Trametes versicolor are compounded, the effect of synergistically improving the lignin degrading capacity can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of lignin degradation, and in particular to a composite lignin-degrading fungus, a fermentation and culture method, an application thereof, and a straw feed. Background Art

[0002] my country has abundant crop straw resources, but its utilization as feed is low. High lignin content is a major factor hindering its use as feed. Lignin is indigestible and ester-linked to cellulose and hemicellulose, components that provide energy for ruminants. This reduces the digestibility and nutritional value of straw as roughage for ruminants.

[0003] Traditional lignin degradation methods have problems such as low efficiency, high cost, and environmental pollution; in recent years, research on microbial degradation of lignin has gradually attracted attention.

[0004] For example, prior art 1: Japanese patent JP2010200707A discloses lignin-degrading microorganisms, and its specification states: "The present inventors used RBBR, Evans blue, and water-soluble lignin as indicators, and screened a library of more than 17,000 microbial strains. Three strains with good decomposition were selected (TAMA 114 strain, TAMA 113 strain, and TAMA 115 strain). These strains were morphologically and molecularly identified, and it was found that they were basidiomycetes belonging to the genera Shirohouraitake and Morinokarebatake. In addition, it is believed that various degradative enzymes such as laccase and peroxidase are involved in the degradation of lignin. The degradation of RBBR in the liquid culture supernatant over time was analyzed as an indicator, and the results showed that the degradation rate of the three candidate strains was faster than that of the control Ceripororipsis strain, and the degradation progressed well in the absence of hydrogen peroxide. The solution was used as an electron donor in the peroxidase reaction, and the three strains were found to be very useful lignin-degrading bacteria."

[0005] As in prior art 2, Chinese Patent 202111443709.5 discloses microbial strains and their applications for lignin degradation. The resulting strain of Sphingomonas cucurbitae is adaptable to the highly acidic and alkaline wastewater conditions generated by industrial production, capable of growing and reproducing well. It also exhibits a strong lignin degradation effect, reducing the lignin content in liquid wastewater by 5-25%. It can also remove lignin from agricultural and forestry waste, reducing its content by 3-10%. This has broad application prospects for treating refractory substances in industrial and agricultural waste, and is also beneficial to ecological protection and sustainable development.

[0006] Both prior art 1 and prior art 2 have discovered microbial strains that can effectively degrade lignin, and both have good degradation effects on lignin. However, for straw with a high lignin content, the degradation ability of a single strain is relatively limited, making it difficult to meet the application needs of straw degradation.

[0007] However, there are two problems with composite strains: (1) If the composite strains are simply a combination of their effects, then at the same total dosage, the lignin degradation effect they produce will be worse than that of a single strain with better degradation effect; (2) There will be antagonism between the strains, and simply combining two or more strains may lead to a significant decrease in the lignin degradation ability of the composite strain. Summary of the Invention

[0008] One of the purposes of the present invention is to provide a composite lignin-degrading fungus, which can produce a synergistic effect of improving the lignin degradation effect by combining white capsule spores and Trametes versicolor, and can well meet the lignin degradation needs of straw.

[0009] Another object of the present invention is to provide a fermentation and culture method for a composite lignin-degrading fungus, which maximizes the lignin degradation ability of the composite strain by optimizing the fermentation and culture conditions.

[0010] At the same time, the present invention also provides a straw feed, in which the lignin is degraded by the composite lignin-degrading fungi of the present invention, and the feed can be effectively digested and utilized by ruminants after being eaten, thereby making full use of the abundant straw resources.

[0011] To achieve the above object, the present invention provides a composite lignin-degrading fungus, comprising white capsule spores and Trametes versicolor, wherein the weight ratio of white capsule spores to Trametes versicolor is 1-2:1-2.

[0012] The present invention also provides a fermentation and cultivation method of a composite lignin-degrading fungus, comprising the following steps:

[0013] Step 1: inoculating and activating Trametes versicolor and White Sac Rhacocystis to obtain activated strains of Trametes versicolor and White Sac Rhacocystis;

[0014] Step 2: inoculating and culturing the activated strain of Trametes versicolor in proportion to obtain a bacterial block;

[0015] Step 3: inoculate and amplify the bacterial block to culture into a liquid bacterial strain, and separate the liquid bacterial strain to obtain the composite lignin-degrading fungus.

[0016] Preferably, the specific operation of step 1 is: activating white capsule rake tooth fungus and Trametes versicolor respectively with PDA culture medium, and rejuvenating them, and sterilizing them at 121°C for 15 minutes to obtain activated white capsule rake tooth fungus strains and activated Trametes versicolor strains; the PDA culture medium is potato extract: 6.0g, glucose: 20.0g, agar: 20.0g, pH value 5.6±0.2, and distilled water 1000mL; the culture conditions are: temperature 28°C, and culture in a constant temperature incubator for 7 days.

[0017] Preferably, the specific operation of step 2 is: inoculating the activated strain of white capsule rake tooth fungus and the activated strain of Trametes versicolor into PDA culture medium in proportion, placing the inoculated plate in a constant temperature incubator at 28°C for 5-7 days, and observing and recording the mutual inhibition between the strains; the PDA culture medium is potato extract: 6.0g, glucose: 20.0g, agar: 20.0g, pH value 5.6±0.2, and distilled water 1000mL.

[0018] Preferably, the specific operation of step 3 is: taking fungal blocks with a fungus puncher, inoculating them into an expansion medium, and shaking culturing them at 28° C. and 180 rpm for 3 days to prepare a seed solution.

[0019] Preferably, the expansion medium is composed of: potato extract powder: 6.0 g, glucose: 20.0 g, and distilled water 1000 mL.

[0020] The seed liquid is inoculated into a liquid bacterial strain enzyme production fermentation medium at a total inoculum volume of 2-7% v / v, and cultured at 180 rpm and 25-40° C. for 5-10 days to obtain a liquid bacterial strain, and the liquid bacterial strain is centrifuged to obtain a supernatant;

[0021] Furthermore, the carbon source of the liquid strain enzyme production fermentation medium is at least one of glucose, cotton straw powder, wheat straw powder, and corn flour.

[0022] Further preferably, the carbon source of the liquid strain enzyme production fermentation medium is cotton straw powder.

[0023] Furthermore, the nitrogen source of the liquid strain enzyme production fermentation medium is at least one of peptone, urea, ammonium tartrate, and ammonium sulfate.

[0024] Further preferably, the nitrogen source of the liquid bacterial strain enzyme production fermentation medium is urea.

[0025] Furthermore, the pH of the liquid bacterial strain enzyme production fermentation medium is 5.0-6.0

[0026] As a preferred technical solution, the composition of the enzyme-producing fermentation medium is: cotton straw powder: 20g, urea: 2g, MgSO4: 0.5g, KH2PO4: 1.0g, Na2HPO4: 0.2g, and distilled water 1000mL.

[0027] The invention discloses an application of a composite lignin-degrading fungus, which is used for degrading straw lignin.

[0028] The invention discloses a straw feed, which is obtained by inoculating the composite lignin-degrading fungus into straw and fermenting the mixture.

[0029] Preferably, the straw is cotton straw.

[0030] More preferably, the method for preparing the straw feed comprises the following steps:

[0031] Step a: Grind 4-5 cm long cotton straw using a grinder to obtain 40 mesh cotton straw powder;

[0032] Step b: Based on the weight of the cotton straw, 0.5% urea, 20% wheat bran, 0.5% gypsum powder and 1% lime powder are mixed to obtain an auxiliary material;

[0033] Step c: mixing cotton straw with auxiliary materials and controlling the moisture content to 65%, sterilizing in an autoclave at 121° C. for 1 hour to obtain cotton straw feed;

[0034] Step d: inoculating 4% of the weight of cotton straw with composite lignin-degrading fungi into cotton straw feed, and fermenting to obtain straw feed.

[0035] Beneficial effects

[0036] Compared with the prior art, the present invention has at least the following advantages:

[0037] (1) The present invention provides a composite lignin-degrading fungus, which is formed by using a composite strain of white capsule rake tooth fungus and color-changing trametes fungus. When the two are combined, they can produce a synergistic effect of improving the lignin degradation ability;

[0038] (2) The present invention provides a fermentation and culture method for a composite lignin-degrading fungus, which maximizes the lignin degradation ability of the composite strain by optimizing the fermentation and culture conditions;

[0039] (3) The present invention provides a straw feed that can be provided to ruminants for consumption and has high digestibility and nutritional value. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the embodiments, but this does not constitute any limitation to the present invention. Any limited modifications made within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0041] In order to explain the technical content of the present invention in detail, further description will be given below in conjunction with the embodiments.

[0042] In the following examples and comparative examples, the Trametes versicolor is Trametes versicolor; the Trametes versicolor is purchased from BNCC Henan Industrial Microbial Strain Engineering Technology Research Center, with the number: BNCC336609; the white capsule spore is purchased from BNCC Henan Industrial Microbial Strain Engineering Technology Research Center, with the number: BNCC353830.

[0043] Example 1

[0044] A composite lignin-degrading fungus is obtained by the following steps:

[0045] Step 1: Adding white capsule rake tooth fungus and Trametes versicolor to PDA culture medium for activation, with the amount of white capsule rake tooth fungus and Trametes versicolor added being 3 mm in diameter and 2 mm in thickness, and then rejuvenating and sterilizing at 121°C for 15 min to obtain activated white capsule rake tooth fungus strains and activated Trametes versicolor strains, respectively; the PDA culture medium consists of 6.0 g potato extract, 20.0 g glucose, 20.0 g agar, pH 5.6±0.2, and 1000 mL distilled water; the culture conditions are: temperature 28°C, incubation in a constant temperature incubator for 7 days;

[0046] Step 2: Inoculate the activated strains of Trametes versicolor and Albizia albizia onto PDA culture medium at a weight ratio of 1:1. Place the inoculated culture dish in a 28°C constant temperature incubator for 7 days to observe the antagonistic effect. The PDA culture medium consists of 6.0 g potato extract, 20.0 g glucose, 20.0 g agar, pH 5.6 ± 0.2, and 1000 mL distilled water.

[0047] Step 3: Using a sterile borer, obtain a fungal block (5 mm in diameter and 2 mm in thickness), inoculate it into an expansion medium, and shake culture it at 28°C and 180 rpm for 3 days to prepare a seed solution; inoculate the seed solution of Trametes albus and Trametes versicolor at an inoculum rate of 4% (v / v) into an enzyme-producing fermentation medium, shake culture it at 180 rpm and 28°C for 6 days to obtain a liquid culture, and centrifuge the liquid culture to obtain a supernatant;

[0048] The composition of the expansion medium is as follows: potato extract powder: 6.0 g, glucose: 20.0 g, distilled water 1000 mL;

[0049] The composition of the enzyme fermentation medium is: cotton straw powder: 20 g, urea: 2 g, MgSO4: 0.5 g, KH2PO4: 1.0 g, Na2HPO4: 0.2 g, distilled water 1000 mL, pH 5.3.

[0050] Example 2

[0051] Step 1: Adding white capsule rake tooth fungus and Trametes versicolor to PDA culture medium for activation, with the amount of white capsule rake tooth fungus and Trametes versicolor added being 3 mm in diameter and 2 mm in thickness, and then rejuvenating and sterilizing at 121°C for 15 min to obtain activated white capsule rake tooth fungus strains and activated Trametes versicolor strains; the PDA culture medium consists of 6.0 g potato extract, 20.0 g glucose, 20.0 g agar, pH 5.6±0.2, and 1000 mL distilled water; the culture conditions are: temperature 28°C, incubation in a constant temperature incubator for 7 days;

[0052] Step 2: Inoculate the activated strains of Trametes versicolor and Albizia albizia onto PDA culture medium at a weight ratio of 2:1. Place the inoculated culture dish in a 28°C constant temperature incubator for 7 days to observe the antagonistic effect. The PDA culture medium consists of 6.0 g potato extract, 20.0 g glucose, 20.0 g agar, pH 5.6 ± 0.2, and 1000 mL distilled water.

[0053] Step 3: Using a sterile borer, obtain a fungal block (5 mm in diameter and 2 mm in thickness), inoculate it into an expansion medium, and shake culture it at 28°C and 180 rpm for 3 days to prepare a seed solution; inoculate the seed solution of Trametes albus and Trametes versicolor at an inoculum rate of 4% (v / v) into an enzyme-producing fermentation medium, shake culture it at 180 rpm and 28°C for 6 days to obtain a liquid culture, and centrifuge the liquid culture to obtain a supernatant;

[0054] The composition of the expansion medium is as follows: potato extract powder: 6.0 g, glucose: 20.0 g, distilled water 1000 mL;

[0055] The composition of the enzyme fermentation medium is: cotton straw powder: 20 g, urea: 2 g, MgSO4: 0.5 g, KH2PO4: 1.0 g, Na2HPO4: 0.2 g, distilled water 1000 mL, pH 5.3.

[0056] Example 3

[0057] Step 1: Adding white capsule rake tooth fungus and Trametes versicolor to PDA culture medium for activation, with the amount of white capsule rake tooth fungus and Trametes versicolor added being 3 mm in diameter and 2 mm in thickness, and then rejuvenating and sterilizing at 121°C for 15 min to obtain activated white capsule rake tooth fungus strains and activated Trametes versicolor strains; the PDA culture medium consists of 6.0 g potato extract, 20.0 g glucose, 20.0 g agar, pH 5.6±0.2, and 1000 mL distilled water; the culture conditions are: temperature 28°C, incubation in a constant temperature incubator for 7 days;

[0058] Step 2: Inoculate the activated strains of Trametes versicolor and Albizia albizia onto PDA culture medium at a weight ratio of 1:2. Place the inoculated culture dish in a 28°C constant temperature incubator for 7 days to observe the antagonistic effect. The PDA culture medium consists of 6.0 g potato extract, 20.0 g glucose, 20.0 g agar, pH 5.6 ± 0.2, and 1000 mL distilled water.

[0059] Step 3: Use a sterile puncher to obtain a fungal block (5 mm in diameter and 2 mm in thickness), inoculate it into an amplification medium, and shake culture it at 28°C and 180 r / min for 3 days to prepare a seed solution; inoculate the seed solution of white capsule rake tooth fungus and color-changing Trametes at an inoculum rate of 4% (v / v) into an enzyme-producing fermentation medium, shake culture it at 180 r / min and 28°C for 6 days to obtain a liquid strain, and centrifuge the liquid strain to obtain a supernatant.

[0060] The composition of the expansion medium is as follows: potato extract powder: 6.0 g, glucose: 20.0 g, distilled water 1000 mL;

[0061] The composition of the enzyme fermentation medium is: cotton straw powder: 20 g, urea: 2 g, MgSO4: 0.5 g, KH2PO4: 1.0 g, Na2HPO4: 0.2 g, distilled water 1000 mL, pH 5.3.

[0062] Comparative Example 1

[0063] A white capsule rake tooth fungus is obtained by the following steps:

[0064] Step 1: A 3 mm diameter and 2 mm thick white cyst spore was activated and rejuvenated using CPDA medium, and sterilized at 121°C for 15 min to obtain an activated white cyst spore strain; the CPDA medium consisted of 10.0 g potato extract, 20.0 g glucose, 3.0 g KH2PO4, 1.5 g MgSO4·7H20, 0.008 g thiamine, 15.0 g agar, pH 6.0, and 1000 mL distilled water, sterilized at 121°C for 15 min; the culture conditions were: a temperature of 28°C in a constant temperature incubator for 7 days;

[0065] Step 2: Using a sterile cork borer, obtain a fungal block (5 mm in diameter and 2 mm in thickness), inoculate it into an expansion medium, and shake culture it at 28°C and 180 rpm for 3 days to prepare a seed solution; inoculate the seed solution of the white capsule rake tooth fungus at an inoculum rate of 4% v / v into an enzyme-producing fermentation medium, shake culture it at 180 rpm and 28°C for 6 days to obtain a liquid culture, and centrifuge the liquid culture to obtain a supernatant;

[0066] The composition of the expansion medium is as follows: potato extract powder: 6.0 g, glucose: 20.0 g, distilled water 1000 mL;

[0067] The composition of the enzyme fermentation medium is: cotton straw powder: 20g, urea: 2g, MgSO4: 0.5g, KH2PO4: 1.0g, Na2HPO4: 0.2g, distilled water 1000mL, pH 5.3, sterilized at 121℃ for 15min.

[0068] Comparative Example 2

[0069] A color-changing Trametes versicolor fungus is obtained by the following steps:

[0070] Step 1: Trametes versicolor strains with a diameter of 3 mm and a thickness of 2 mm were activated and rejuvenated using CPDA medium, and sterilized at 121°C for 15 min to obtain an activated strain of Trametes versicolor. The CPDA medium consisted of 10.0 g potato extract, 20.0 g glucose, 3.0 g KH2PO4, 1.5 g MgSO4·7H20, 0.008 g thiamine, 15.0 g agar, pH 6.0, and 1000 mL distilled water. The strains were sterilized at 121°C for 15 min. The culture conditions were: a temperature of 28°C in a constant temperature incubator for 7 days.

[0071] Step 2: Using a sterile borer, obtain a fungal block (5 mm in diameter and 2 mm in thickness), inoculate it into an expansion medium, and culture it with shaking at 28°C and 180 rpm for 3 days to prepare a seed solution; inoculate the seed solution of Trametes versicolor at an inoculum rate of 4% v / v into an enzyme-producing fermentation medium, and culture it with shaking at 180 rpm and 28°C for 6 days to obtain a liquid culture, which is then centrifuged to obtain a supernatant;

[0072] The composition of the expansion medium is as follows: potato extract powder: 6.0 g, glucose: 20.0 g, distilled water 1000 mL;

[0073] The composition of the enzyme fermentation medium is: cotton straw powder: 20g, urea: 2g, MgSO4: 0.5g, KH2PO4: 1.0g, Na2HPO4: 0.2g, distilled water 1000mL, pH 5.3, sterilized at 121℃ for 15min.

[0074] Performance Testing

[0075] 1. Detection of lignin degradation enzyme activity

[0076] The liquid culture was centrifuged in a centrifuge at 10,000 rpm / min for 5 minutes, and the obtained supernatant was the crude enzyme solution.

[0077] (1) Laccase activity assay: The ABTS method was used. ABTS was used as the reaction substrate. First, 3.3 mL of 100 mmol / L acetic acid-sodium acetate buffer (pH 4.5) was added, followed by 0.5 mL of 0.5 mmol / L ABTS solution, and then 200 μL of crude enzyme solution. The mixture was mixed and kept in a 30°C water bath for 3 min. The absorbance change was then measured at 420 nm.

[0078] (2) Manganese peroxidase activity determination method: MnSO4 method was used. MnSO4 was used as the reaction substrate. First, 2.5 mL of 50 mmol / L succinic acid-sodium succinate buffer (pH 4.5) was added, followed by 0.4 mL of 1.6 mmol / L MnSO4 solution, and then 1 mL of crude enzyme solution. 100 μL of 10 mmol / L H2O2 solution was added to start the reaction. The mixture was mixed and kept in a 37°C water bath for 3 min. The absorbance change was then measured at 240 nm.

[0079] (3) Lignin peroxidase activity assay: The VA (Veratrater Alcohol) method was used. Veratrater alcohol was used as the reaction substrate. First, 2.5 mL of 250 mmol / L tartaric acid-sodium tartrate buffer (pH 3.0) was added, followed by 0.4 mL of 10 mmol / L resveratrate alcohol, followed by 1 mL of crude enzyme solution, and then 100 μL of 10 mmol / L H2O2 solution was added to initiate the reaction. The mixture was mixed and kept in a 30°C water bath for 3 min. The absorbance change was then measured at 310 nm.

[0080] (4) Enzyme activity calculation method

[0081] Enzyme activity calculation formula: (△OD / ε*b*△t)*(V 总 / V 酶 )*106

[0082] Where: △OD is the absorbance change value within time t,

[0083] b is the thickness of the cuvette (cm),

[0084] t is the reaction time (min),

[0085] V 总 is the volume of the reaction system (mL),

[0086] V 酶 is the volume of enzyme solution in the reaction (mL),

[0087] ε is the molar extinction number (M -1 .cm -1 ), ABTS: ε420 = 36000M -1 .cm -1 , Mn 3+ :ε240=6500M -1 .cm -1 ,VA:ε310=9300M -1 .cm -1 .

[0088] The supernatants obtained in Examples 1-3 and Comparative Examples 1-2 were tested according to the above-mentioned detection method. The results are shown in Table 1.

[0089] Table 1 Results of enzyme activity tests of bacterial strains obtained in Examples 1-3 and Comparative Examples 1-2

[0090]

[0091] According to the results in Table 1, we can see that:

[0092] According to the data of Examples 1-3, the present invention uses a combination of white capsule rake tooth fungus and versicolor Trametes, which can make the activities of laccase, lignin peroxidase and manganese peroxidase higher; among them, when the ratio of white capsule rake tooth fungus and versicolor Trametes is 1:1, the activity of laccase, lignin peroxidase and manganese peroxidase is best improved, and the improvement effect is significant.

[0093] According to the data comparison of Example 1 and Comparative Examples 1 and 2, under the condition of the same bacterial content, the combination of Trametes albopictus and Trametes versicolor in the present invention can synergistically enhance the activities of laccase, lignin peroxidase and manganese peroxidase.

[0094] Application Example 1

[0095] A straw feed is prepared by the following steps:

[0096] Step a: crushing the cotton stalks with a crusher to obtain cotton stalks of 4-5 cm in length;

[0097] Step b: Based on the weight of the cotton straw, 0.5% urea, 20% wheat bran, 0.5% gypsum powder and 1% lime powder are mixed to obtain an auxiliary material;

[0098] Step c: mixing cotton straw with auxiliary materials and controlling the moisture content to 65%, sterilizing in an autoclave at 121° C. for 1 hour to obtain cotton straw feed;

[0099] Step d: 4% by weight of cotton straw of Example 1 was inoculated into cotton straw feed, and aerobic fermentation was carried out for 24 hours with stirring once, and fermentation was continued for 14 days.

[0100] Application Example 2

[0101] A straw feed is prepared by the following steps:

[0102] Step a: crushing the cotton stalks with a crusher to obtain cotton stalks of 4-5 cm in length;

[0103] Step b: Based on the weight of the cotton straw, 0.5% urea, 20% wheat bran, 0.5% gypsum powder and 1% lime powder are mixed to obtain an auxiliary material;

[0104] Step c: mixing cotton straw with auxiliary materials and controlling the moisture content to 65%, sterilizing in an autoclave at 121° C. for 1 hour to obtain cotton straw feed;

[0105] Step d: 4% by weight of cotton straw of Example 1 was inoculated into cotton straw feed, and the mixture was sealed and fermented for 14 days.

[0106] Comparative Application Example 1

[0107] A straw feed fermented with white sac fungus is prepared by the following steps:

[0108] Step a: crushing the cotton stalks with a crusher to obtain cotton stalks of 4-5 cm in length;

[0109] Step b: Based on the weight of the cotton straw, 0.5% urea, 20% wheat bran, 0.5% gypsum powder and 1% lime powder are mixed to obtain an auxiliary material;

[0110] Step c: mixing cotton straw with auxiliary materials and controlling the moisture content to 65%, sterilizing in an autoclave at 121° C. for 1 hour to obtain cotton straw feed;

[0111] Step d: 4% by weight of cotton straw of Comparative Example 1 was inoculated into cotton straw feed, and the mixture was sealed and fermented for 14 days.

[0112] Application Comparative Example 2

[0113] A straw feed fermented by Trametes versicolor is prepared by the following steps:

[0114] Step a: crushing the cotton stalks with a crusher to obtain cotton stalks of 4-5 cm in length;

[0115] Step b: Based on the weight of the cotton straw, 0.5% urea, 20% wheat bran, 0.5% gypsum powder and 1% lime powder are mixed to obtain an auxiliary material;

[0116] Step c: mixing cotton straw with auxiliary materials and controlling the moisture content to 65%, sterilizing in an autoclave at 121° C. for 1 hour to obtain cotton straw feed;

[0117] Step d: 4% by weight of cotton straw of Comparative Example 2 was inoculated into the cotton straw feed, and the mixture was sealed and fermented for 14 days.

[0118] Effect test

[0119] Lignin degradation rate test

[0120] The fermented straw feed obtained from Application Example 1-2 and Application Comparative Example 1-2 was tested using the paradigm acid detergent lignin (ADL) test method. The results are shown in Table 2.

[0121] Table 2 Results of lignin degradation rate of fermented straw feed obtained by using Example 1-2 and Comparative Example 1-2

[0122] Lignin degradation rate% Application Example 1 32.5 Application Example 2 30.01 Comparative Application Example 1 20.05 Application Comparative Example 2 15.8

[0123] According to the results in Table 2, we can see that:

[0124] According to the lignin degradation rates of Application Example 1 and Application Example 2, the composite lignin-degrading fungi of the present invention can exert excellent lignin degradation ability regardless of whether the straw feed is fermented in an aerobic environment or an anaerobic environment, among which the fermentation of straw feed in an aerobic environment can further enhance the lignin degradation effect of the composite lignin-degrading fungi.

[0125] According to the data comparison of Application Example 2 and Application Comparative Example 1 and Application Comparative Example 2, it can be seen that the composite lignin-degrading fungus obtained by combining white-capped tricholoma and Trametes versicolor in the present invention not only has no antagonistic effect, but even has the effect of synergistically enhancing the lignin degradation ability; theoretically, if white-capped tricholoma and Trametes versicolor are combined in a 1:1 ratio, the lignin degradation rate should be between 15.8-20.05% when the effects are simply superimposed. However, Application Example 2 of the present application showed a lignin degradation rate of 30.03, which fully proves that the combination of white-capped tricholoma and Trametes versicolor has a synergistic effect.

[0126] The embodiments presented herein are merely embodiments selected from a combination of all possible embodiments. The appended claims should not be limited by the embodiments describing the present invention. Some numerical ranges used in the claims include subranges therein, and variations in these ranges should also be covered by the appended claims.

Claims

1. A composite lignin-degrading fungus, characterized in that White capsule rake tooth fungus and color-changing Trametes, the weight ratio of white capsule rake tooth fungus to color-changing Trametes is 1-2:1-2.

2. A fermentation and cultivation method for a composite lignin-degrading fungus, characterized in that: The steps include: Step 1: inoculating and activating Trametes versicolor and White Sac Rhacocystis to obtain activated strains of Trametes versicolor and White Sac Rhacocystis; Step 2: inoculating and culturing the activated strain of Trametes versicolor in proportion to obtain a bacterial block; Step 3: inoculate and amplify the bacterial block to culture into a liquid bacterial strain, and separate the liquid bacterial strain to obtain the composite lignin-degrading fungus.

3. The fermentation and cultivation method of the composite lignin-degrading fungus according to claim 2, characterized in that: The specific operation of step 1 is: activating and rejuvenating white cyst strains and Trametes versicolor strains respectively with PDA culture medium, sterilizing at 121° C. for 15 minutes to obtain activated white cyst strains and activated Trametes versicolor strains; the PDA culture medium is 200 g of peeled potatoes, 20 g of glucose, 17 g of agar, and 1000 mL of distilled water; and the culture conditions are: culturing at 28° C. in a constant temperature incubator for 7 days.

4. The fermentation and cultivation method of the composite lignin-degrading fungus according to claim 2, characterized in that: The specific operation of step 2 is: inoculating the activated strain of white capsule rhabdocystis and the activated strain of Trametes versicolor on PDA culture medium in proportion, placing the inoculated plate in a constant temperature incubator at 28° C. for 5-7 days, and observing and recording the mutual inhibition between the strains; the PDA culture medium is potato extract powder: 6.0g, glucose: 20.0g, agar: 20.0g, pH 5.6±0.2, distilled water 1000mL.

5. The fermentation and cultivation method of the composite lignin-degrading fungus according to claim 2, characterized in that: The specific operation of step 4 is as follows: taking a fungal block with a fungus puncher, inoculating it into an expansion medium, and shaking and culturing it at 28°C and 180 rpm for 3 days to prepare a seed liquid; inoculating the seed liquid into a liquid strain enzyme production fermentation medium at an inoculum amount of 2-7% v / v, shaking and culturing it at 180 rpm and 25-40°C for 5-10 days to obtain a liquid strain, and centrifuging the liquid strain to obtain a supernatant.

6. The fermentation and cultivation method of the composite lignin-degrading fungus according to claim 5, characterized in that: The carbon source of the liquid bacterial strain enzyme production fermentation medium is at least one of glucose, cotton straw powder, wheat straw powder and corn straw powder.

7. The fermentation and cultivation method of the composite lignin-degrading fungus according to claim 5, characterized in that: The nitrogen source of the liquid bacterial strain enzyme production fermentation medium is at least one of peptone, urea, ammonium tartrate and ammonium sulfate.

8. The fermentation and cultivation method of the composite lignin-degrading fungus according to claim 5, characterized in that: The pH of the liquid bacterial strain enzyme production fermentation medium is 5.0-6.

0.

9. A use of the composite lignin-degrading fungus according to claim 1, characterized in that: The composite lignin-degrading fungus is used to degrade straw lignin.

10. A straw feed, characterized in that: The composite lignin-degrading fungus according to claim 1 is inoculated into straw and fermented.

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