Low-temperature straw degrading bacterium epicoccum fungus NJAU-F2G6 and application thereof

Abstract

The invention discloses a low-temperature straw degrading bacterium epicoccum fungus NJAU-F2G6, which is preserved in the China General Microbiological Culture Collection Center on March 31, 2025, and has the preservation number of CGMCC No.41876. The invention further discloses a preparation method of the low-temperature straw degrading bacterium epicoccum fungus NJAU-F2G6. The invention discloses application of the bacillus subtilis to low-temperature straw degradation and crop growth promotion. The invention also discloses a microbial inoculum prepared from the microbial inoculum and application of the microbial inoculum in low-temperature straw degradation and crop growth promotion. The results of a screening test and a low-temperature soil cultivation test show that the strain NJAU-F2G6 can promote degradation of corn straws at a low temperature of 10 DEG C. Two-season pot experiment results show that (NJAU-F2G6) inoculation treatment has a good growth promoting effect on corn plants while greatly improving the degradation rate of corn straws compared with non-inoculation treatment. The invention provides a strain resource and a technical support for promoting crop growth while enhancing low-temperature degradation of straws.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural microorganism technology, in particular to a low-temperature straw degrading bacterium of the genus Pediococcus NJAU-F2G6 and its application. BACKGROUND

[0002] As a large agricultural country, China has a considerable amount of straw, with a total of about 800 million tons per year, of which corn straw accounts for about 25%. Due to the large biomass of corn straw and the low collection coefficient, the treatment cost has been high, which has seriously restricted the efficient promotion of corn straw resource utilization. Among the many straw treatment methods, direct return to the field is one of the main means of straw resource utilization due to its relatively simple operation and low cost. However, a large number of studies have shown that if the straw cannot be degraded in time, it will have an adverse effect on the growth of the next crop, such as hindering seed germination and affecting root growth. The application of microbial inoculants for promoting degradation has become an effective and environmentally friendly solution to accelerate straw degradation, improve soil fertility, and promote crop growth.

[0003] Northeast China is one of the main grain producing areas in China and plays a crucial role in corn planting. However, the climate in this region is cold, and the soil temperature is below 20℃ for most of the year. The planting season is from May to October, and the soil temperature is already below 10℃ by the time of harvest. The low-temperature environment greatly limits the activity of straw-degrading microorganisms in the soil, making the straw degradation process extremely slow. Low degradation efficiency not only affects the timely recovery of soil fertility but also directly hinders the sowing and growth of the next crop, seriously threatening the sustainable development of local agriculture.

[0004] Although there are many corn straw degradation microbial inoculants currently available at room temperature, there is a severe lack of efficient degradation inoculant products for the low-temperature environment in Northeast China. The existing room-temperature inoculants have a significantly reduced activity at low temperatures, which cannot meet the actual agricultural production needs in Northeast China. In view of this, the present application focuses on the low-temperature environment (10℃) to simulate the degradation process of corn straw under low-temperature conditions, and constructs a selection and verification system with corn straw as the main carbon source. A low-temperature straw degrading bacterium of the genus Pediococcus NJAU-F2G6 is successfully located and obtained, in order to provide strong strain resources and technical support for efficient straw return to the field in Northeast China and effectively solve the straw treatment problems in local agricultural production. SUMMARY

[0005] The purpose of the present application is to provide a low-temperature straw degrading bacterium of the genus Pediococcus NJAU-F2G6 and its application to solve the deficiencies of the prior art.

[0006] The purpose of the present application can be achieved by the following technical solutions: The first aspect of the present application provides a low-temperature straw degrading bacteria of the genus Zymoacus, Zymoacus sp., named NJAU-F2G6, which is classified as Zymoacus sp. Epicoccum and is preserved in the China General Microbiological Culture Collection Center on March 31, 2025, with the preservation number of CGMCC No.41876.

[0007] The second aspect of the present application provides a bacterial agent prepared from the above-mentioned low-temperature straw degrading bacteria of the genus Zymoacus, Zymoacus sp., named NJAU-F2G6.

[0008] Further, the bacterial agent is prepared by the following method: the Zymoacus sp., NJAU-F2G6, with the preservation number of CGMCC No.41876, is subjected to liquid fermentation, and after the fermentation is completed, the mycelium is removed by filtration to obtain a fermentation broth, and the fermentation broth is adjusted to obtain a spore content to obtain a bacterial suspension, i.e., the bacterial agent.

[0009] Further, the bacterial agent is prepared by the following method: the Zymoacus sp., NJAU-F2G6, with the preservation number of CGMCC No.41876, is inoculated into a first liquid medium to perform liquid fermentation, the first liquid medium includes a PDA liquid medium, the liquid fermentation conditions are: a fermentation temperature of 28-30℃, a rotation speed of 170-190r / min, and a fermentation time of 96-120h, after the fermentation is completed, the mycelium is removed by multi-layer gauze filtration to obtain a fermentation broth, and the fermentation broth is adjusted with a second liquid medium to obtain a spore content to obtain a bacterial suspension, i.e., the bacterial agent, the second liquid medium includes a 1 / 2MS liquid medium, and the spore content in the bacterial suspension is ≥5×10 6 / ml.

[0010] The third aspect of the present application provides the role of the above-mentioned low-temperature straw degrading bacteria of the genus Zymoacus, Zymoacus sp., named NJAU-F2G6, in low-temperature straw degradation and in promoting crop growth.

[0011] Further, the straw is corn straw.

[0012] Further, the crop is corn.

[0013] The fourth aspect of the present application provides the application of the above-mentioned bacterial agent in low-temperature straw degradation and in promoting crop growth.

[0014] Further, the straw is corn straw.

[0015] Further, the crop is corn.

[0016] The beneficial effects of the present application are: This invention addresses the problem of corn straw not being rapidly degraded in low-temperature environments in Northeast China, which in turn affects the growth of subsequent crops. By identifying a low-temperature straw-degrading bacterium, Ephesococcus fungus NJAU-F2G6, this study aims to facilitate efficient straw return to fields in the region. Screening tests and low-temperature soil cultivation experiments demonstrated that strain NJAU-F2G6 can promote corn straw degradation at temperatures as low as 10°C. Two potted plant trials conducted over two seasons demonstrated that inoculated treatment with NJAU-F2G6 significantly improved corn straw degradation compared to uninoculated treatment, while also promoting growth in the corn plants. This invention provides strain resources and technical support for enhancing low-temperature straw degradation while promoting crop growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a photo of strain NJAU-F2G6 after being cultured on PDA solid medium at 28°C for 120 hours.

[0018] Figure 2 This is a phylogenetic tree constructed based on the 16S rRNA gene sequence of strain NJAU-F2G6.

[0019] Figure 3 This is the effect of strain NJAU-F2G6 treatment on the degradation rate of corn straw in the first season of potted test.

[0020] Figure 4 This is the effect of strain NJAU-F2G6 on the aboveground length of corn plants in the first season of potted test.

[0021] Figure 5 This is the effect of strain NJAU-F2G6 on the stem diameter of corn plants in the first season of potted test.

[0022] Figure 6 This is the effect of strain NJAU-F2G6 on the dry weight-root of maize plants in the first season of potted test.

[0023] Figure 7 This is the effect of strain NJAU-F2G6 on the dry weight of aboveground parts of maize plants in the first season of potted test.

[0024] Figure 8 This is the effect of strain NJAU-F2G6 treatment on the degradation rate of corn straw in the second season potted test.

[0025] Figure 9 This is the effect of strain NJAU-F2G6 on the aboveground length of corn plants in the second pot test.

[0026] Figure 10 This is the effect of strain NJAU-F2G6 on the stem diameter of corn plants in the second season of potted test.

[0027] Figure 11 This is the effect of strain NJAU-F2G6 on the dry weight of corn plants (aboveground part) in the second season of potted test.

[0028] Figure 12 This is the effect of low-temperature soil test strain NJAU-F2G6 treatment on the degradation rate of corn straw.

[0029] In the bar graph, ns means p>0.05, the difference is not significant; * means 0.01 <P ≤0.05,差异显著;**表示0.001<P≤0.01,差异极显著;***表示0.0001<P≤0.001,差异极其显著;****表示P≤0.0001,差异极度显著。 Biomaterial deposit information

[0030] strain NJAU-F2G6, taxonomically named Epicococcus Epicoccum sp., deposited in the General Microbiology Center of China Culture Collection Administration, the deposit address is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, the deposit date is March 31, 2025, and the deposit number is CGMCC No.41876. DETAILED DESCRIPTION

[0031] The present invention will be further explained below in conjunction with the examples and accompanying drawings. The following examples are intended only to illustrate the present invention, but are not intended to limit the scope of the present invention. The test methods in the following examples are conventional methods unless otherwise specified. The test materials used in the following examples were purchased from conventional biochemical reagent stores unless otherwise specified.

[0032] Unless otherwise specified, the culture medium and other materials used in the following examples are as follows: PDA solid medium (g / L): 6.0 g potato extract powder, 20.0 g glucose, 20.0 g agar powder. PDA liquid medium without agar powder.

[0033] Cellulose Congo red medium (g / L): sodium nitrate 1.0g, disodium hydrogen phosphate 1.2g, potassium dihydrogen phosphate 0.9g, magnesium sulfate 0.5g, potassium chloride 0.5g, yeast powder 0.5g, acid hydrolyzed casein 0.5g, Congo red 0.2g, cellulose powder 5.0g, agar powder 15.0g.

[0034] 1 / 2MS liquid culture medium (g / L): ammonium nitrate 1.0 g, dipotassium hydrogen phosphate 0.75 g, potassium dihydrogen phosphate 1.5 g, magnesium sulfate heptahydrate 0.05 g, anhydrous calcium chloride 0.005 g, EDTA dihydrate 0.005 g.

[0035] Corn stalks: corn stalks from Gongzhuling city, Heilongjiang province, the stems and stalks which are hard to degrade were selected and dried in an oven at 60℃ for 48h.

[0036] The following examples involve culture dishes (plates) with a diameter of 90 mm, unless otherwise specified.

[0037] Example 1 Isolation and screening of functional bacterial strains 1. Isolation of bacterial strains Soil samples were obtained from Gongzhuling city, Jilin province, including corn stalks full amount of return to the field soil (a), three times return to the field soil (b), five times return to the field soil (c) and no return to the field soil (d). Soil samples were also obtained from Haerbin city, Heilongjiang province, including corn stalks no return to the field soil (e) and corn stalks full amount of return to the field soil (f). Soil samples were also obtained from Zhaodong city, Heilongjiang province, including corn stalks full amount of return to the field soil (g) and corn stalks full amount of return to the field soil (h) for 11 years.

[0038] Corn stalks were cut into 2-3cm long strips, 200g soil (dry weight) and 2g corn stalks (dry weight) were added to each treatment, and sterile water was added to 75% of the maximum water holding capacity. Eight treatments were incubated at 10℃. On the 10th day (referred to as the first batch), the 30th day (referred to as the second batch) and the 120th day (referred to as the third batch), corn stalk samples from each treatment were used for screening (the present application relates to the second batch). After washing the surface soil of the corn stalks with sterile water (pre-cooled to 10℃), they were placed in 30ml sterile water (pre-cooled to 10℃), shaken at 200r / min for 1h at room temperature, and allowed to stand for 10min. The supernatant was used as the initial concentration and diluted to 10 -3 ,10 -4 ,10 -5 After three gradients, 0.1ml of the bacterial suspension was taken and added to the surface of the cellulose Congo red medium for culture, in order to screen potential bacterial strains with straw degradation ability. Each sample was repeated three times, and incubated at 10℃ for about 5d. Morphologically different colonies were picked and purified for use, and stored in a glycerol tube in an ultra-low temperature freezer for future use. The naming method was as follows: the abbreviation of the culture medium (fungi were named F and bacteria were named X in the screening, and the present application relates to fungi) + the sampling batch (the 30th day, i.e. the second batch) + the soil treatment number (capital letters / small letters) + the serial number, for example: F2G6 represents the sixth strain screened from the g soil treatment on the 30th day on the cellulose Congo red medium.

[0039] 2. Primary screening of functional bacterial strains 2 g (dry weight) of chopped corn stalks (chopped into strips of about 2-3 cm) were added to each sterile culture dish for the purpose of determining the degradation rate of the strain. Fungal strains purified from the above-mentioned cellulose Congo red medium were randomly selected and inoculated into PDA liquid culture medium and cultured in a shaker at 28°C and 170 rpm for 96 h. After fermentation, the mycelium was removed by filtration using two layers of gauze, and the fermentation broth was adjusted to a spore content of ≥5×10 with 1 / 2 MS liquid medium. 6 / ml (5×10 6 10 ml of the culture medium (1 / 2 MS liquid medium) was added to the aforementioned culture dish, along with a control treatment (CK) (10 ml of 1 / 2 MS liquid medium added to the culture dish). The culture was then incubated at 10°C for 15 days. The remaining corn straw in the culture dish was then oven-dried at 60°C for 48 hours and weighed to calculate the corn straw degradation rate.

[0040] Corn straw degradation rate = (2g - remaining corn straw amount (g)) / 2g × 100% Thus, the strain NJAU-F2G6 with strong low-temperature degradation function of corn straw was obtained, as shown in Table 1 (the strains with low corn straw degradation rate are not listed one by one).

[0041] Table 1 Ability of screened strains to degrade corn straw at low temperature Strains Corn stalk degradation rate NJAU-F2G6 5% CK 3% Other representative strains isolated from the same batch 1% Example 2 Identification of strain NJAU-F2G6 After the strain NJAU-F2G6 was cultured on PDA solid medium at 28°C for 120 h, Figure 1 As shown, the colony morphology is nearly circular, light yellow to golden yellow / orange, with lighter white edges (after 48 hours of culture, the colonies are white as a whole, with some having light yellow centers and white edges. With aging, possibly due to the release of yellow or orange pigments, after 120 hours of culture, the colonies appear light yellow to golden yellow / orange, with lighter white edges), with irregular petal-shaped edges. Figure 2 As shown in the figure, the phylogenetic tree constructed based on the 16S rRNA gene sequence of strain NJAU-F2G6 showed that strain NJAU-F2G6 was closely related to Epicoccum layuense NR 158265.1 had the highest homology, reaching 99.6%. Combining the colony morphology characteristics of strain NJAU-F2G6 and the phylogenetic tree constructed by 16S rRNA gene sequence, strain NJAU-F2G6 was identified as a fungus of the genus Epicococcus ( Epicoccum sp.). The strain NJAU-F2G6 has been deposited in the General Microbiology Center of China Culture Collection Administration of Microorganisms with the deposit number CGMCC No.41876.

[0042] Example 3: The effect of strain NJAU-F2G6 on the biomass of corn plants and the degradation rate of corn stalks was studied using a pot experiment (first season pot experiment) The pot experiment was conducted in a glass greenhouse at the Binjiang Campus of Nanjing Agricultural University in Nanjing, Jiangsu Province, from December 2024 to January 2025. The corn variety used was a common corn variety (Jinhai No. 5). The corn seeds were sterilized and washed at room temperature, and then germinated at 30°C in an incubator. The test bacteria were NJAU-F2G6 bacterial suspension: after activation, NJAU-F2G6 was added to PDA liquid medium and fermented in a shaker. The fermentation conditions were: fermentation temperature 28°C, rotation speed 170 r / min, fermentation time 96 h. After fermentation, the mycelium was removed by filtering with two layers of gauze to obtain the fermentation broth. The fermentation broth was adjusted with 1 / 2MS liquid medium to obtain the NJAU-F2G6 bacterial suspension. The spore content in the NJAU-F2G6 bacterial suspension was ≥5×10 6 6 The dried northeast black soil was mixed with vermiculite and quartz sand (vermiculite:quartz sand volume ratio = 2:1) through a 10-mesh screen (black soil:vermiculite and quartz sand volume ratio = 6:4) to obtain the soil for the pot experiment. The soil was added to each pot to a depth of 5 cm, and 2 g (dry weight) of cut corn stalks (cut into 2-3 cm long strips) were added to each pot in a 200-mesh bag. Then, 10 ml of 1 / 2MS liquid medium / bacteria (NJAU-F2G6 bacterial suspension) was added to the bag, and then the same amount of soil was added to each pot to a depth of 10 cm (the volume of the pot was 0.9 L, and the total volume of the soil added was about 750 cm 3 ). The pots were placed in a greenhouse (greenhouse conditions: average temperature 20°C, air humidity 80%, 16 h light / 8 h dark), and the same amount of water was added to each pot to completely immerse it. On the 5th day, the germinated corn seedlings were planted in the pots, with 3 corn seedlings per pot. Then, the water was added as needed. On the 30th day after planting the corn seedlings, the corn plants were removed, and the length of the aboveground part (from the junction of the aboveground and underground parts to the top of the corn plant) and the stem thickness (at the junction of the aboveground and underground parts) were measured. Then, the corn plants were cut at the junction of the aboveground and underground parts using scissors, and the underground and aboveground parts were placed separately in envelopes and placed in an oven at 60°C for 48 h. The dry weight of the roots and the dry weight of the aboveground part were measured, respectively. The bag containing the corn stalks buried in the soil was dug up, washed with water to remove the surface soil, and the internal corn stalks were removed and placed in a small aluminum box. After drying in an oven at 60°C for 48 h, the weight of the remaining corn stalks was measured, and the degradation rate of the corn stalks was calculated.

[0043] ​The pot experiment was set up with 2 treatments, which were: 1) control group (CK), adding 1 / 2MS liquid medium 10 ml; 2) treatment group (F2G6), adding NJAU-F2G6 bacterial suspension 10 ml. Each treatment had 4 replicates (i.e. 4 pots for each treatment).

[0044] The corn stalk degradation rate results are shown in Figure 3 The corn stalk degradation rate of the control group without inoculation was only 8.4%, and the corn stalk degradation rate of the treatment group inoculated with NJAU-F2G6 bacterial suspension was 9.5%. Compared with the control group without inoculation, the corn stalk degradation rate of the treatment group inoculated with NJAU-F2G6 bacterial suspension increased by 13.1%.

[0045] The biomass of each treatment group is shown in Figures 4-7 From the length of the above-ground part of the corn plant, stem diameter, dry weight-root, and dry weight-above-ground, the growth of the corn plants in the treatment group inoculated with NJAU-F2G6 bacterial suspension was significantly better than that of the corn plants in the control group without inoculation.

[0046] Example 4: Verification of the effect of strain NJAU-F2G6 on corn plant biomass and corn stalk degradation rate using a pot experiment (second season pot experiment) The pot experiment was set up with 2 treatments, which were: 1) control group (CK), adding 1 / 2MS liquid medium 10 ml; 2) treatment group (F2G6), adding NJAU-F2G6 bacterial suspension 10 ml. Each treatment had 4 replicates (i.e. 4 pots for each treatment). 6 6 The pot experiment was set up with 2 treatments, which were: 1) control group (CK), adding 1 / 2MS liquid medium 10 ml; 2) treatment group (F2G6), adding NJAU-F2G6 bacterial suspension 10 ml. Each treatment had 4 replicates (i.e. 4 pots for each treatment).The soil for the pot experiment was obtained by uniformly mixing air-dried Northeast China black soil with vermiculite and quartz sand (vermiculite: quartz sand volume ratio = 2:1) after passing through a 10-mesh screen (black soil: vermiculite and quartz sand volume ratio = 6:4). The soil was added to each pot to a depth of 5 cm, 2 g (dry weight) of cut corn stalks (cut into 2-3 cm long strips) packaged in a 200-mesh bag were added to each pot, and then 1 / 2MS liquid medium / bacterial agent (NJAU-F2G6 bacterial suspension) 10 ml was added to the bag according to the treatment. Then, an equal amount of soil was added to each pot to a depth of 10 cm (the volume of the pot was 0.9 L, and the total volume of soil added was about 750 cm3 The pots were placed in a greenhouse (greenhouse conditions: average temperature of 20℃, air humidity of 80%, 16h light / 8h dark), and an equal amount of water was added to each pot to completely immerse the corn seedlings. On the 5th day, the corn seedlings were transplanted into the pots, 2 corn seedlings were planted in each pot, and then 1 / 2MS liquid medium was added as needed. On the 30th day after the corn seedlings were transplanted, the corn plants were removed, the length of the aboveground part of the corn plants (the length from the junction of the aboveground part and the underground part to the top of the corn plant), the stem thickness (the thickness of the stem at the junction of the aboveground part and the underground part) were measured, and then the corn plants were cut at the junction of the aboveground part and the underground part with scissors, the aboveground part of the corn plants was placed in an envelope and placed in an oven at 60℃ for 48h, and the dry weight of the aboveground part of the corn plants was measured. The net bag containing the corn straw buried in the soil was washed with water to remove the surface soil, and the internal corn straw was taken out and placed in a small aluminum box, which was placed in an oven at 60℃ for 48h, and then the weight of the remaining corn straw was measured to calculate the corn straw degradation rate.

[0047] The pot experiment was divided into 2 treatments, namely: 1) control group (CK), 1 / 2MS liquid medium 10ml was added; 2) treatment group (F2G6), NJAU-F2G6 bacterial suspension 10ml was added. Each treatment had 4 replicates (i.e. 4 pots per treatment).

[0048] The corn straw degradation rate results are shown in Table 3 Figure 8 The corn straw degradation rate of the non-inoculated control group was only 9.9%, and the corn straw degradation rate of the NJAU-F2G6 bacterial suspension inoculation treatment group was 15.3%. Compared with the non-inoculated control group, the corn straw degradation rate of the NJAU-F2G6 bacterial suspension inoculation treatment group increased by 54.5%, and the overall trend was consistent with the results of the first pot experiment (Example 3), further verifying the excellent ability of the NJAU-F2G6 strain to promote corn straw degradation.

[0049] The biomass of each treatment is shown in Table 4 Figures 9-11 From the length of the aboveground part of the corn plants, the stem thickness, and the dry weight of the aboveground part, the growth of the corn plants in the NJAU-F2G6 bacterial suspension inoculation treatment group was significantly better than that of the corn plants in the non-inoculated control group. This result is also consistent with the results of the first pot experiment (Example 3), further verifying the excellent growth-promoting effect of the NJAU-F2G6 strain on corn plants while promoting corn straw degradation.

[0050] The results of the two pot experiments effectively demonstrate the excellent ability of the NJAU-F2G6 strain to promote corn straw degradation, as well as the excellent ability to promote corn plant growth while promoting corn straw degradation. The difficulty of straw degradation in northeast China is one of the reasons affecting straw return, and the present application provides a strain resource and technical support for enhancing low-temperature degradation of straw and promoting crop growth.

[0051] Example 5 Further verification of the effect of strain NJAU-F2G6 on corn straw degradation rate by low temperature incubation test The low temperature incubation test site was located in the low temperature incubation test site of Nanjing Agricultural University in Nanjing, Jiangsu Province. The test time was from March 2025 to May 2025. The test bacteria were NJAU-F2G6 bacterial suspension: after activation, NJAU-F2G6 was added to PDA liquid medium and cultured at 28°C on a shaker at 170 r / min for 96 h. After fermentation, the mycelium was removed by filtering with two layers of gauze, and the fermentation broth was obtained. The fermentation broth was adjusted with 1 / 2MS liquid medium to obtain NJAU-F2G6 bacterial suspension. The spore content in NJAU-F2G6 bacterial suspension was ≥5×10 6 6 The test used 250 ml size tissue culture bottles, and each tissue culture bottle was added with a part of air-dried northeast black soil passing through a 10 mesh screen, 2 g (dry weight) of cut corn straw (cut into 2-3 cm long strips) packaged with a 200 mesh bag was added to each bottle, and 10 ml of 1 / 2MS liquid medium / bacteria (NJAU-F2G6 bacterial suspension) was added to the bag, and the remaining soil was used to bury the bag (the total amount of soil added to each tissue culture bottle was 160 g of dry weight). Incubate at 10°C for 70 days, and regularly supplement water to maintain the soil moisture content at 70% of the maximum water holding capacity of the soil. After incubation, the bag containing corn straw buried in the soil was taken out, the surface soil was washed off with water, and the internal corn straw was taken out and placed in a small aluminum box, which was placed in an oven at 60°C and dried for 48 h. The weight of the remaining corn straw was measured, and the corn straw degradation rate was calculated.

[0052] The low temperature incubation test was divided into 2 treatments, namely 1) control group (CK), adding 1 / 2MS medium 10 ml; 2) treatment group (F2G6), adding NJAU-F2G6 bacterial suspension 10 ml. Each treatment has 3 replicates (i.e. 3 tissue culture bottles for each treatment).

[0053] The corn straw degradation rate results are shown in Figure 12 The corn straw degradation rate of the non-inoculated control group was only 8.3%, while the corn straw degradation rate of the NJAU-F2G6 bacterial suspension inoculation treatment group was 17.2%. Compared with the non-inoculated control group, the corn straw degradation rate of the NJAU-F2G6 bacterial suspension inoculation treatment group increased by 107.2%, further verifying the ability of NJAU-F2G6 strain to promote corn straw degradation under low temperature conditions (10°C).​

Claims

1. A low-temperature straw-degrading fungus, Echinococcus sp. NJAU-F2G6, is named Echinococcus sp. Epicoccum sp., deposited in the General Microbiology Center of China Culture Collection Administration of Microorganisms, with the deposit date of March 31, 2025, and the deposit number is CGMCC No.41876.

2. A bacterial agent prepared from the low-temperature straw-degrading bacterium Ephelococcus fungus NJAU-F2G6 according to claim 1.

3. The microbial agent according to claim 2, characterized in that The bacterial agent is prepared by the following method: liquid fermentation of Epicococcus fungus NJAU-F2G6 with a preservation number of CGMCC No. 41876 is carried out, after the fermentation is completed, the mycelium is filtered out to obtain a fermentation liquid, and the spore content of the fermentation liquid is adjusted to obtain a bacterial suspension, namely the bacterial agent.

4. The microbial agent according to claim 3, characterized in that The bacterial agent is prepared by the following method: inoculating the Epicococcus fungus NJAU-F2G6 with a deposit number of CGMCC No. 41876 into a first liquid culture medium for liquid fermentation, wherein the first liquid culture medium comprises a PDA liquid culture medium, and the liquid fermentation conditions are as follows: a fermentation temperature of 28-30° C., a rotation speed of 170-190 r / min, and a fermentation time of 96-120 h; after the fermentation is completed, filtering with multi-layer gauze to remove mycelia to obtain a fermentation liquid; adjusting the spore content of the fermentation liquid with a second liquid culture medium to obtain a bacterial suspension, namely the bacterial agent; the second liquid culture medium comprises a 1 / 2MS liquid culture medium, and the spore content of the bacterial suspension is ≥5×10 6 pcs / ml.

5. Use of the low-temperature straw degrading bacteria Ephelococcus fungus NJAU-F2G6 according to claim 1 in low-temperature straw degradation and crop growth promotion, wherein: The crop is corn.

6. The use according to claim 5, characterized in that The straw is corn straw.

7. Use of the microbial agent according to any one of claims 2 to 4 in low-temperature straw degradation and crop growth promotion, wherein: The crop is corn.

8. The use according to claim 7, characterized in that The straw is corn straw.

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