Streptomyces griseorubens with cuticle degradation capability, fungicide and application of streptomyces griseorubens

Abstract

The invention relates to streptomyces griseorubens with cuticle degradation capacity, a fungicide and application of the streptomyces griseorubens. The name of the strain is Streptomyces griseorubens F-1, the preservation number is CCTCC NO: M 2024899, and the Streptomyces griseorubens F-1 can rapidly and stably grow by using a cheap culture medium, is wide in adaptive temperature range, and is especially suitable for being applied under the condition of normal temperature (15-40 DEG C). The strain can be used for degrading plant residues by a biological method, and degrading cuticles, cellulose, hemicelluloses, lignin and the like of the plant residues, so that high-value utilization of the plant residues is effectively promoted, and the strain has very high economic value and ecological value.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microbial technology, and particularly relates to a Streptomyces griseorubidus with cuticle degradation ability, a microbial agent and application thereof. BACKGROUND

[0002] China is a major agricultural country, and the theoretical resource amount of straw in China in 2022 reached 977 million tons. Lignocellulosic biomass is a key resource for realizing sustainable development by replacing the petroleum production system. Plants resist the destruction of their tissues by natural environment and organisms through complex structures and chemical properties, and the cuticle is the first layer of barrier. Although the compositions of cuticles of different species are different, they are all composed of the following main components: cutin, a polyester and wax naturally polymerized by C16 or C18 hydroxyl fatty acids. In the process of interaction with the outside world, the cuticle has a significant hydrophobic effect. Through solvent extraction test, wax is the key to the hydrophobic effect. The physical barrier and surface hydrophobicity of the recalcitrant polyester give the plant strong stress resistance, but also hinder the natural degradation efficiency of agricultural waste. Decomposing or removing the cuticle is a key step to utilize the components such as cellulose and hemicellulose of plant fibers. Therefore, it is very important to find a method that can efficiently and energy-efficiently degrade the cuticle of straw, and it provides a possible direction for future straw biodegradation application and research.

[0003] Because the cuticle covers the surface of plant fibers, the effective contact of natural microorganisms, enzymes, etc. with cellulose and lignin is reduced, thereby reducing the utilization level of polysaccharides and lignin located inside. At present, the commonly used cuticle treatment methods are chemical method and physical method. The chemical method has the problems of potential harm caused by toxic chemicals, the need to purchase expensive equipment, high cost, etc. The physical method has the problems of high energy consumption, high equipment maintenance cost, environmental and safety hazards, etc.

[0004] Northeast China is an important grain production base in China, and a large amount of crop straw agricultural waste is produced every year. The surface of the straw after harvest is covered with a recalcitrant cuticle, and this structure has a great influence on the subsequent resource utilization of the straw. Screening of straw cuticle degrading bacteria can enrich the resource library of straw cuticle degrading bacteria, provide a basis for the research and development of cuticle degrading bacteria, and possibly provide new resources for the decomposition and destruction of plant residue cuticle.

[0005] In the "five utilization" of straw in China, fertilizer is the largest utilization method and an effective way to handle large amounts of surplus straw. Direct straw return to the field is the main utilization method of crop straw fertilizer. This protective use of straw is beneficial to the needs of the soil and the environment. However, there are many problems with in-situ return. Slow decomposition of straw in the field is the primary concern for annual cultivation. Slow decomposition leads to a series of problems such as nutrient differences, crop diseases and pests, etc. Compared with in-situ return of crop straw, compost return has high efficiency, complete fermentation and can promote the growth of more microorganisms, reduce the abundance of pathogenic microorganisms, but the use cost is increased due to collection, storage, crushing and fermentation. Whether it is in-situ return or compost return, the cutin layer of straw has a certain hindering effect on its decomposition process. The straw return often uses the method of crushing and turning, and the depth of straw turning affects the decomposition rate, that is, the abundance of different functional bacterial species in different depth of soil is different. The decomposition of straw after return is a process of nutrient release, organic carbon mineralization and soil organic carbon balance, which is mediated by different soil microorganisms with specific functions. Therefore, selecting appropriate microorganisms is of great significance for efficient degradation of plant residue cutin and promoting straw return. SUMMARY

[0006] In view of the problems existing in the prior art, the present application provides a streptomyces with cutin degradation ability, which can effectively degrade cutin under normal temperature conditions.

[0007] The technical solution of the present application to solve the above technical problems is as follows:

[0008] The present application provides a streptomyces griseorubens, the strain name is streptomyces griseorubens F-1, and the preservation number of the streptomyces griseorubens F-1 is CCTCC NO: M 2024899. The strain has been preserved in the China Center for Type Culture Collection (CCTCC) on May 10, 2024, and the preservation address is Wuhan, Wuhan University, China.

[0009] The present application screens a strain F-1 capable of effectively degrading cutin from the return-to-field soil in Heilongjiang. The strain can grow rapidly and stably using a cheap medium, has a wide temperature adaptation range, is especially suitable for normal temperature (15-40℃) conditions, and can adapt to different treatment scenarios. The strain can be used for biological degradation of plant residues, degrading cutin, cellulose, hemicellulose and lignin of plant residues, thereby effectively promoting the high-value utilization of plant residues, and has high economic value and ecological value.

[0010] The strain F-1 grows smaller on Gause No. 1 solid medium, the colony size is 2 mm, the colony is not obvious in protrusion, is grayish white and opaque, the edge is neat, the surface is rough, and then develops in a powder actinomycete shape, and there is differentiation of intramural hyphae and aerial hyphae. After 72 hours of culture on Gause No. 1 solid medium, an electron microscope is used to take a picture, a single conidium is about 1 μm long, and the width is 0.7-0.9 μm, and the hyphae are spiral.

[0011] After the Streptomyces griseorubiginosus F-1 is cultured in Gause No. 1 medium added with treated corn stalk epidermis for 5 days, the weight loss rate of the corn stalk epidermis is 28.87%. After the Streptomyces griseorubiginosus F-1 is cultured in carbon-free mineral salt medium added with treated corn stalk epidermis for 5 days, the weight loss rate of the corn stalk epidermis is 22.57%.

[0012] The 16S rRNA gene sequence of the Streptomyces griseorubiginosus F-1 includes the nucleotide sequence shown in SEQ ID NO: 3.

[0013] The present application provides a straw decomposition microbial agent, which includes the above-mentioned Streptomyces griseorubiginosus and / or the fermentation product of the Streptomyces griseorubiginosus.

[0014] In the microbial agent, in addition to the Streptomyces griseorubiginosus and the fermentation product of the Streptomyces griseorubiginosus, an auxiliary material can also be included. Other microorganisms can also be added to the microbial agent, and the other microorganisms can be compounded with the strain F-1 provided by the present application. The present application does not have special requirements for the dosage form of the straw decomposition microbial agent, for example, it can be a liquid preparation, a solid preparation, or other dosage forms.

[0015] Further, the cutin degradation microbial agent can also include a culture medium for culturing the strain F-1.

[0016] The present application provides a preparation method of a straw decomposition microbial agent, which includes the following steps: culturing the above-mentioned Streptomyces griseorubiginosus F-1 using a culture medium.

[0017] The present application provides a fermentation culture method of the above-mentioned Streptomyces griseorubiginosus, which includes the following steps: inoculating the Streptomyces griseorubiginosus F-1 into a culture medium and performing fermentation culture.

[0018] Further, the fermentation culture temperature can be 15-40 ℃.

[0019] The present application provides the application of the above-mentioned Streptomyces griseorubiginosus in any one or more of (1) to (5);

[0020] (1) degrading the cutin of plant residues;

[0021] (2) degrading plant residues;

[0022] (3) degrading cellulose;

[0023] (4) degrading hemicellulose;

[0024] (5) degrading lignin.

[0025] The present application provides the above-mentioned microbial agent for use in any one or more of (1) to (5);

[0026] (1) degrading plant residue cuticle;

[0027] (2) degrading plant residue;

[0028] (3) degrading cellulose;

[0029] (4) degrading hemicellulose;

[0030] (5) degrading lignin.

[0031] The Streptomyces griseorubiginosus F-1 and the microbial agent provided by the present application can grow rapidly and stably using a cheap culture medium, have a wide temperature range, and can be applied under different temperature conditions, and have a good plant residue cuticle degradation effect. The Streptomyces griseorubiginosus F-1 and the microbial agent can be used for biodegradation of plant residue cuticle and degradation of substances containing cuticle (for example, straw), thereby improving the utilization rate of the substances containing cuticle, and have high economic value and ecological value.

[0032] The present application provides a method for degrading cuticle using the above-mentioned Streptomyces griseorubiginosus, comprising the following steps: inoculating the above-mentioned Streptomyces griseorubiginosus into a culture medium containing cuticle, and carrying out fermentation culture. The method of the present application has the advantages of not causing secondary pollution and being green and environmentally friendly.

[0033] The fermentation culture temperature can be 15-40℃.

[0034] The present application provides a method for degrading cuticle using the above-mentioned microbial agent, comprising the following steps: inoculating the above-mentioned microbial agent into a culture medium containing cuticle, and carrying out fermentation culture.

[0035] The fermentation culture temperature can be 15-40℃.

[0036] The above-mentioned culture medium can contain water-soluble starch, inorganic salt, etc. in addition to the cuticle (for example, straw epidermis, etc.).

[0037] The present application isolates Streptomyces griseorubiginosus F-1 from soil, and the strain and the microbial agent prepared using the strain can effectively degrade cuticle and can normally grow at a temperature of 15℃ to 40℃, so that the cuticle on the surface of the straw in the fermentation liquid is completely destroyed. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1Colony morphology of strain F-1 (left) and electron micrograph of conidial filament (right).

[0039] Figure 2 Phylogenetic tree constructed for strain F-1 and related strains.

[0040] Figure 3 Results of weight loss and degradation rate in different media.

[0041] Figure 4 Results of strain dry weight and pH in different media.

[0042] Figure 5 Scanning electron micrograph of corn stalk epidermis after different treatments.

[0043] Figure 6 Water contact angle of corn stalk epidermis after different treatments. DETAILED DESCRIPTION

[0044] The principles and features of the present application are described below in conjunction with the accompanying drawings, in which the examples are used to explain the present application and are not intended to limit the scope of the present application.

[0045] In order to better understand the present application, the present application is further described in detail below in conjunction with examples, but the scope of the present application claimed is not limited to the scope represented by the examples. The present application generally and / or specifically describes the materials used in the experiments and the experimental methods. Although many materials and methods used to achieve the purpose of the present application are well known in the art, the present application is described as detailed as possible.

[0046] The units of the amount of substances added in each of the following media are g / L. The media are used after sterilization.

[0047] The mineral salt medium without carbon is prepared in the following proportions: K2HPO4·3H2O 0.92 g / L, KH2PO4 0.7 g / L, MgSO4·7H2O 0.7 g / L, (NH4)2SO4 1 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, MnSO4·H2O 0.001 g / L, prepared with distilled water, pH 7.2-7.6.

[0048] Carbon-free mineral salt solid medium, prepared in the following proportions: K2HPO4·3H2O 0.92 g / L, KH2PO4 0.7 g / L, MgSO4·7H2O 0.7 g / L, (NH4)2SO4 1.0 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, MnSO4·H2O 0.001 g / L, agar powder 18-20 g / L, prepared with distilled water, pH 7.2-7.6.

[0049] Gao's No. 1 medium, prepared in the following proportions: soluble starch 20 g / L, KNO3 1 g / L, NaCl 0.5 g / L, K2HPO4·3H2O 0.5 g / L, MgSO4·7H2O 0.5 g / L, FeSO4·7H2O 0.01 g / L, prepared with distilled water, pH 7.4-7.6.

[0050] Method for preparing Gao's No. 1 solid medium, comprising the following steps: adding agar powder 18-20 g / L to Gao's No. 1 medium.

[0051] Straw cuticle solid medium, prepared in the following proportions: prepare carbon-free mineral salt solid medium, and add 3 pieces of 1 cm x 1 cm treated corn straw epidermis in the plate. The method for preparing the treated corn straw epidermis comprises the following steps: harvest corn straw, naturally air dry, form a gap between the epidermis and the stem, peel off the surface epidermis, boil in a solution containing 4 g / L oxalic acid and 16 g / L ammonium oxalate for 4 h to remove carbohydrates, wash with sterile deionized water and dry, and cut into 1 cm x 1 cm square thin pieces. Use after sterilization.

[0052] Polycaprolactone selection plate, prepared in the following proportions: dissolve 1 g of polycaprolactone (PCL) in 25 mL of acetone, then mix with 25 mL of distilled water to obtain 50 mL of flocculent solution, then add to 950 mL of carbon-free mineral salt medium, and if a solid plate is prepared, additionally add agar powder 18-20 g / L.

[0053] Paraffin selection plate, prepared in the following proportions: take 4 g of paraffin (melting point 56-58℃) and add to 1 L of carbon-free mineral salt medium. When taking out the liquid medium, it should be handled gently, and it should be allowed to cool while standing, avoiding the paraffin from adhering to the surface of the glass bottle and solidifying. If a solid plate is prepared, additionally add agar powder 18-20 g / L to the liquid medium, pour the plate at above 60℃, and shake well before each time of pouring the plate.

[0054] In the present invention, the meanings of straw cuticle and cuticle are the same.

[0055] The primer 27F and the primer 1492R are both synthesized by Shanghai Pisen Biotech Co., Ltd. The sequence of the primer 27F is 5'-AGAGTTTGATCCTGGCTCAG-3' (SEQ ID NO: 1); and the sequence of the primer 1492R is 5'-CTACGGCTACCTTGTTACGA-3' (SEQ ID NO: 2).

[0056] The bacterial genomic DNA extraction kit is purchased from Tiangeng Biochemical Technology (Beijing) Co., Ltd., and the item number is DP302-02. The AxyPrep DNA gel recovery kit is purchased from AxyPrep, and the item number is AP-GX-50. The 10x Buffer (containing 2.5mM Mg 2+ ) is purchased from Shanghai Yuanmu Biotechnology Co., Ltd., and the item number is YM-MY162J. The Taq polymerase is purchased from TaKaRa, and the item number is DRR20AM. The dNTP is purchased from TaKaRa, and the item number is D4030A.

[0057] The instruments, reagents, materials and the like involved in the following examples are all conventional instruments, reagents, materials and the like in the prior art if no special description is made, and can be obtained through a regular commercial channel. The experimental methods, detection methods and the like involved in the following examples are all conventional experimental methods, detection methods and the like in the prior art if no special description is made.

[0058] The following is introduced through specific examples.

[0059] Example 1

[0060] In July 2021, soil samples were collected in the oilfield square of Daqing City, Heilongjiang Province (124.92 °N, 46.61 °E), Chaha Yang Farm of Qiqihar (124.24 °N, 48.23 °E) and Longyouhu artificial lake of Nantong City, Jiangsu Province (32.42 °N, 129.16 °E). The collection method includes the following steps: using a sterile shovel to sample multiple points, taking 50g of sample from each site, quickly placing the collected sample into a sterile polyethylene sealed bag, bringing it back to the laboratory under low temperature conditions, and storing it in a 4 °C refrigerator for subsequent screening.

[0061] 5g of soil sample was weighed into a conical flask (conical flask volume 100mL) containing 60mL of sterilized distilled water, and cultured at 30 °C, 150rpm on a shaker for 1h for enrichment. After standing for 30min, the supernatant was taken as the original bacterial liquid. The original bacterial liquid was diluted 10 -5 , 10 -6 and 10 -7The diluted bacterial liquid was respectively coated on polycaprolactone selective solid plates, paraffin selective solid plates and straw cutin solid medium plates, 50 μL of the diluted bacterial liquid was coated on each plate, and each plate was cultured at 30°C for 3 days. Single colonies were picked and streaked on plates, the types of the streaked plates were the same as those of the coated bacterial liquid, and the plates were cultured at 30°C for 3 days. The above method was repeated to separate and purify until pure culture strains were obtained, and the pure culture strains were preserved at -80°C for standby use.

[0062] 5 g of the soil sample was weighed and added into a conical flask (conical flask volume: 100 mL) containing 60 mL of sterilized distilled water, and was cultured at 35°C and 150 rpm for 1 h to enrich, and was left to stand for 30 min. The supernatant was taken as the original bacterial liquid. The original bacterial liquid was diluted by 10 -5 , 10 -6 and 10 -7 times, and the diluted bacterial liquid was respectively coated on polycaprolactone selective solid plates, paraffin selective solid plates and straw cutin solid medium plates, 50 μL of the diluted bacterial liquid was coated on each plate, and each plate was cultured at 35°C for 3 days. Single colonies were picked and streaked on plates, the types of the streaked plates were the same as those of the coated bacterial liquid, and the plates were cultured at 35°C for 3 days. The above method was repeated to separate and purify until pure culture strains were obtained, and the pure culture strains were preserved at -80°C for standby use.

[0063] 5 g of the soil sample was weighed and added into a conical flask (conical flask volume: 100 mL) containing 60 mL of sterilized distilled water, and was cultured at 40°C and 150 rpm for 1 h to enrich, and was left to stand for 30 min. The supernatant was taken as the original bacterial liquid. The original bacterial liquid was diluted by 10 -5 , 10 -6 and 10 -7 times, and the diluted bacterial liquid was respectively coated on polycaprolactone selective solid plates, paraffin selective solid plates and straw cutin solid medium plates, 50 μL of the diluted bacterial liquid was coated on each plate, and each plate was cultured at 40°C for 3 days. Single colonies were picked and streaked on plates, the types of the streaked plates were the same as those of the coated bacterial liquid, and the plates were cultured at 40°C for 3 days. The above method was repeated to separate and purify until pure culture strains were obtained, and the pure culture strains were preserved at -80°C for standby use.

[0064] The above method was used to obtain the primary screening strains. The primary screening strains were re-screened, including the following steps: after the primary screening strains were subcultured and stabilized, they were inoculated on straw cutin solid medium plates and cultured at 40°C for 3-5 days. Samples that could grow colonies on the straw cutin solid medium plates were selected, and the degradation effect of the corn straw cutin layer was observed by scanning electron microscopy. The degradation effect of the corn straw cutin layer was used as a decisive factor for subsequent strain selection.

[0065] The strain F-1 is obtained by the above method, and the strain F-1 is obtained from a sample of Chahayang Farm. The strain F-1 is cultured on a Gao's No. 1 solid medium at 35°C for 3 days, and the colony morphology is as shown in the left part of FIG. 1. As can be seen, the strain F-1 grows smaller, the colony size is 2 mm, the colony is not obviously protruding, is grayish white and opaque, the edge is neat, the surface is rough, and then develops in a powder actinomycete shape, with differentiation of intramural hyphae and aerial hyphae; the scanning electron microscope (SEM) photograph of the conidial filament is as shown in the right part of FIG. 1. As can be seen, the single conidium is about 1 μm long and 0.7-0.9 μm wide, and the hyphae are in a spiral shape. Figure 1 Figure 1

[0066] In terms of growth characteristics, the strain F-1 is cultured at different temperatures, and it is verified that the strain F-1 can grow at 15-40°C, and the growth speed of the strain F-1 is faster at 30-40°C within 5 days.

[0067] Example 2

[0068] The bacterial genomic DNA extraction kit is used to extract the bacterial DNA, and the universal primers 27F / 1492R are used for PCR amplification.

[0069] The PCR amplification reaction system comprises: genomic DNA (20 ng / μL) 1 μL, 10×Buffer (containing 2.5 mM Mg 2+ ) 5 μL, Taq polymerase (5 u / μL) 1 μL, dNTP (10 mM) 1 μL, primer 27F (10 μM) 1.5 μL, primer 1492R (10 μM) 1.5 μL, and ddH2O is supplemented to 50.0 μL.

[0070] The PCR amplification reaction program comprises: pre-denaturation at 95°C for 5 min; denaturation at 95°C for 30 s, annealing at 58°C for 30 s, extension at 72°C for 1.5 min, 35 cycles; and final extension at 72°C for 7 min.

[0071] The PCR product is recovered by using the AxyPrep DNA gel recovery kit. The PCR amplification product is sent to Shanghai Paixinnuo Biological Technology Co., Ltd. for sequencing. The BLAST software is used to perform homology comparison analysis on the obtained sequence and the GenBank database.

[0072] After the strain F-1 is amplified and sequenced by using the universal primers of bacteria, the NCBI database blast comparison is performed, and the phylogenetic tree is constructed by using the MAGE11.0 software. As shown in FIG. 2, the strain F-1 has the closest genetic relationship with Streptomyces griseoviolaceus, reaching 100%. Figure 2

[0073] The 16S rRNA gene sequence of the strain F-1 is shown as SEQ ID NO: 3.​​​

[0074]

[0075] The strain F-1 is preserved in the China Center for Type Culture Collection (CCTCC) located in Wuhan University, Wuhan, China, on May 10, 2024, with the preservation number CCTCC NO: M2024899 and the preservation name Streptomyces griseorubens F-1.

[0076] When the straw cutin wax is used as a degradation index, the ordinary method is difficult to verify the degradation effect. The present application uses straw epidermis as culture, and analyzes and verifies the surface changes by various methods to verify and analyze the effect.

[0077] Example 3

[0078] (1) Preparation of culture medium containing treated corn straw epidermis

[0079] The treated corn straw epidermis is added to Gao's No. 1 medium and carbon-free mineral salt medium, respectively, and the final concentration of the treated corn straw epidermis is 2 g / L, to obtain a culture medium containing treated corn straw epidermis.

[0080] The preparation method of the treated corn straw epidermis includes the following steps: harvesting corn straw, naturally air-drying, forming a gap between the epidermis and the stem, peeling off the surface epidermis, boiling in a solution containing 4 g / L oxalic acid and 16 g / L ammonium oxalate for 4 h to remove carbohydrates, washing with sterile deionized water, and drying, cutting into square slices with a size of ≥0.5 cm×0.5 cm, sterilizing, and using.

[0081] (2) The strain F-1 is activated with carbon-free mineral salt medium at 35°C for 24 h to obtain activated F-1 bacterial liquid, which is used in the following experiments.

[0082] (3) The activated F-1 bacterial liquid is inoculated into the culture medium containing treated corn straw epidermis prepared in step (1), and the inoculation amount is 6% (volume percentage), the liquid volume of the treated corn straw epidermis medium is 50% (i.e. the ratio of medium volume to conical flask volume is 50%), and the culture is carried out at 35°C with a shaking speed of 120 rpm. On the 5th day, the corn straw epidermis is taken out, washed to remove the attached mycelium, dried in an oven at 80°C for 10 h, and then weighed with a centesimal balance. The changes of cellulose, hemicellulose and lignin in the corn straw epidermis are determined by CXC-06 crude fiber tester. Six parallel treatments are set in each group.

[0083] Weight loss rate = (initial weight of dry weight of corn straw epidermis - final mass of dry weight of corn straw epidermis) / initial weight of dry weight of corn straw epidermis * 100%.

[0084] The degradation rate of cellulose = (initial weight of cellulose - final mass of cellulose) / initial weight of cellulose * 100%.

[0085] The degradation rate of hemicellulose = (initial weight of hemicellulose - final mass of hemicellulose) / initial weight of hemicellulose * 100%.

[0086] The degradation rate of lignin = (initial weight of lignin - final mass of lignin) / initial weight of lignin * 100%.

[0087] The detection results of the weight loss rate are shown in Table A. Figure 3 As shown in Table A, it can be seen that, through the determination of the weight loss of the straw skin, the weight loss rate of the corn straw skin was 28.87% after the strain F-1 was cultured in the Gao's No. 1 medium added with the treated corn straw skin for 5 days. The weight loss rate of the corn straw skin was 22.57% after the strain F-1 was cultured in the inorganic salt medium added with the treated corn straw skin for 5 days. The above results show that the strain F-1 can degrade the straw skin whether in the Gao's No. 1 medium or in the inorganic salt medium. The effect of the Gao's No. 1 medium is better than that of the inorganic salt medium.

[0088] The detection results of the degradation rates of cellulose, hemicellulose and lignin are shown in Table B. Figure 3 As shown in Table B, it can be seen that, after fermentation for 5 days, the strain F-1 can obviously degrade cellulose, hemicellulose and lignin, and the degradation effect of the strain F-1 on lignin is the best. Compared with the inorganic salt medium, the strain F-1 has a better degradation effect when cultured in the Gao's No. 1 medium.

[0089] Example 4

[0090] The effect of different media on the growth of the strain F-1 was detected, and the experimental method included the following steps:

[0091] (1) The strain F-1 was activated to obtain the activated F-1 bacterial solution, and the activation method was referred to Example 3.

[0092] (2) The F-1 bacterial solution activated in step (1) was inoculated into the Gao's No. 1 medium at an inoculation amount of 6% (volume percent), and was cultured in a 35℃, 120rpm shaking bed for 24h to obtain a bacterial solution. The bacterial solution was inoculated into the Gao's No. 1 medium at an inoculation amount of 6% (volume percent), and was cultured in a 35℃, 120rpm shaking bed for 100h.

[0093] (3) The activated strain F-1 liquid in step (1) was inoculated into the mineral salt medium at 6% (volume percentage), and cultured at 35°C with a rotation speed of 120 rpm for 24h to obtain a bacterial liquid; the bacterial liquid was inoculated into the mineral salt medium at an inoculation amount of 6% (volume percentage), and cultured at 35°C with a rotation speed of 120 rpm for 100h.

[0094] (4) Under sterile operation, the fermentation liquid was taken out every 10h, and 2mL of the fermentation liquid was taken out each time, and three repetitions were set for each sample. The pH of the fermentation liquid was measured by using an acidity meter, and the dry weight of the strain was detected.

[0095] The experimental results are shown in Figure 4 A. It can be seen from Figure 4 A that F-1 was cultured in the Gao No. 1 medium, and the logarithmic phase was 20h-60h, and tended to be stable after 70h; F-1 was cultured in the mineral salt medium, and grew rapidly at 30h-40h, and tended to be stable after 60h, and the logarithmic phase time of F-1 was shorter under the condition of the mineral salt medium. It can be seen from Figure 4 B that F-1 had a partial downward trend of pH within 10h-40h of the culture, and the pH of F-1 presented a significant upward trend in the later culture period, whether in the mineral salt medium or the Gao No. 1 medium.

[0096] Example 5

[0097] The cuticle morphology under different treatments was analyzed by using a scanning electron microscope (SEM), and four groups of A, B, C and D were set.

[0098] The surface of the straw in group A was treated by cooking and high-pressure sterilization, and the preparation method included the following steps: corn straws were harvested, and the surface and the stem formed a gap after natural air drying, the surface skin was peeled off, boiled in a solution containing 4g / L oxalic acid and 16g / L ammonium oxalate for 4h to remove carbohydrates, washed with sterile deionized water and dried, cut into square thin slices with a size of 0.8cm×0.8cm, and sterilized. The above skin was dried in an oven at 60°C for 8h, and then gold plating film was sprayed, and the straw skin was observed by using a scanning electron microscope.

[0099] The surface of the straw in group B was immersed in a mixed solution of chloroform-methanol (volume ratio 1:1) for 24h, and the preparation method included the following steps: corn straws were harvested, and the surface and the stem formed a gap after natural air drying, the surface skin was peeled off, immersed in a mixed solution of chloroform-methanol (volume ratio 1:1) for 24h, washed with sterile deionized water and dried, cut into square thin slices with a size of 0.8cm×0.8cm, and sterilized. The above skin was dried in an oven at 60°C for 8h, and then gold plating film was sprayed, and the straw skin was observed by using a scanning electron microscope.

[0100] Group C consisted of straw epidermis from a 3-day fermentation of F-1. The preparation method included the following steps: F-1 was cultured in Gao's Medium No. 1, and the straw epidermis was prepared as 0.8 cm × 0.8 cm square slices, following the same experimental method as in Example 3. After 3 days of culture, the straw epidermis was removed. The epidermis was oven-dried at 60°C for 8 hours, then spray-coated with gold, and observed using a scanning electron microscope.

[0101] Group D consisted of straw epidermis from a 5-day fermentation of F-1. The preparation method included the following steps: F-1 was cultured in Gao's Medium No. 1. The straw epidermis was prepared as a 0.8 cm × 0.8 cm square slice, following the same experimental method as in Example 3. After 5 days of incubation, the straw epidermis was removed and the hyphae were scraped off. The epidermis was oven-dried at 60°C for 8 hours, then spray-coated with gold and observed using a scanning electron microscope.

[0102] The experimental results are as follows Figure 5 As shown, A is the straw epidermis after digestion and high-pressure sterilization, B is the straw epidermis after soaking in a chloroform-methanol (volume ratio 1:1) mixed solution for 24 hours, C is the straw epidermis after fermentation and culture of strain F-1 for 3 days, and D is the straw epidermis after fermentation and culture of strain F-1 for 5 days.

[0103] After boiling and high-pressure sterilization, there was no significant change in the surface of the straw, and a small amount of wrinkles appeared on the keratin wax ( Figure 5 A). After immersing in a chloroform-methanol (volume ratio 1:1) mixed solution for 24 hours, the epidermis underwent some changes, changing the smooth state of the keratin wax surface and becoming rough, but the keratin wax and keratin were not destroyed. Figure 5 B).

[0104] The corn stalk epidermis treated with strain F-1 showed significant differences from the other treatments. After culturing for 3 days, the hyphae of strain F-1 attached to the epidermis, some epidermal cells were exposed, some of the epidermal cells had blocked gaps, and the stomata on the epidermis were also closed and blocked ( Figure 5 C). After culturing strain F-1 for 5 days and wiping off the mycelium, it can be seen that the keratin wax disappears, the epidermal hairs and epidermal cells are completely exposed, gaps appear between some epidermal cells, the squares between the epidermal cells are exposed, the guard cells in the stomata are compressed to the middle, the stomata are opened, and the keratin and keratin wax are degraded ( Figure 5 D).

[0105] Example 6

[0106] The water contact angle of the stratum corneum under different treatments was measured and set as group A, group B and group C.

[0107] A group is the untreated corn stalk epidermis, the preparation method comprises the following steps: harvesting corn stalk, after natural drying, the epidermis and the stem form a gap, the surface epidermis is peeled, washed with sterile deionized water and dried, cut into 0.8cm*0.8cm square sheet, sterilized and used.

[0108] B group is the pretreated corn stalk epidermis, the preparation method comprises the following steps: harvesting corn stalk, after natural drying, the epidermis and the stem form a gap, the surface epidermis is peeled, boiled in 4g / L oxalic acid and 16g / L ammonium oxalate solution for 4h to remove carbohydrates, washed with sterile deionized water and dried, cut into 0.8cm*0.8cm square sheet. Sterilized and used.

[0109] C group is the corn stalk epidermis treated by strain F-1, the preparation method comprises the following steps: according to the method of example 3, F-1 is inoculated in high's No.1 medium containing treated corn stalk epidermis, the inoculation amount is 6%, the size of corn stalk epidermis is 0.8*0.8cm, and the fermentation culture is carried out at 35 DEG C for 3d, the corn stalk epidermis attached by mycelium is taken, and the mycelium is wiped off.

[0110] Each group of epidermis is dried in an oven at 60 DEG C for 8h. The test is carried out in a constant temperature environment of 20 DEG C, the test liquid is deionized water (1.5 μL), and the sessile drop method is used, that is, the deionized water is dropped on the surface of the coating, the left and right contact angles are taken as the contact angle of the measured area each time, three different areas of each sample are tested to calculate the average value.

[0111] The water contact angle of the corn stalk epidermis after different treatments is as shown in the table. Figure 6 A is the untreated epidermis, B is the epidermis after pretreatment, and C is the epidermis of the stalk treated by strain F-1. It can be seen that after the epidermis of the stalk is treated by strain F-1, the average value of the contact angle is 60.59 DEG, the hydrophobicity decreases, that is, the cutin wax of the epidermis of the stalk is degraded after being treated by the strain, the hydrophobicity decreases, and the epidermis of the stalk is more easily infiltrated by water.

[0112] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A Streptomyces griseus with stratum corneum degradation ability, characterized in that: The strain is named Streptomyces griseorubens F-1, and its deposit number is CCTCC NO: M2024899.

2. A bacterial agent, characterized in that The invention comprises the Streptomyces griseus and / or the fermentation product of the Streptomyces griseus according to claim 1.

3. A fermentation and culturing method of Streptomyces griseus according to claim 1, characterized in that: The following steps are involved: The Streptomyces griseus is inoculated into the culture medium and fermented.

4. The fermentation and culture method of Streptomyces griseus according to claim 3, wherein The fermentation temperature is 15-40°C.

5. Use of the Streptomyces griseus according to claim 1 in any one or more of (1) to (5); (1) Degradation of the cuticle of plant residues; (2) Degradation of plant residues; (3) Degradation of cellulose; (4) degradation of hemicellulose; (5) Degradation of lignin.

6. Use of the bacterial agent according to claim 2 in any one or more of (1) to (5); (1) Degradation of the cuticle of plant residues; (2) Degradation of plant residues; (3) Degradation of cellulose; (4) degradation of hemicellulose; (5) Degradation of lignin.

7. A method for degrading the cuticle of plant residues using the Streptomyces griseorhizoides according to claim 1, characterized in that: The method comprises the following steps: inoculating the griseo-reddish Streptomyces described in claim 1 into a culture medium containing the cuticle of plant residues, and performing fermentation culture.

8. The method according to claim 7, characterized in that: The fermentation temperature is 15-40°C.

9. A method for degrading the cuticle of plant residues using the bacterial agent according to claim 2, characterized in that: The method comprises the following steps: inoculating the bacterial agent according to claim 2 into a culture medium containing the cuticle of plant residues, and fermenting and culturing the culture medium.

10. The method according to claim 9, characterized in that: The fermentation temperature is 15-40°C.

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