Microbacterium bingsonii LYY-05 for degrading straws and application of microbacterium bingsonii LYY-05

Abstract

The invention relates to the technical field of microbial degradation, and particularly discloses a microbacterium bingsonii LYY-05 for degrading straws and application of the microbacterium bingsonii LYY-05. The microbacterium bingsonii LYY-05 is preserved in the China Center for Type Culture Collection on August 19, 2025, the preservation number of the microbacterium bingsonii LYY-05 is CCTCC NO: M 20251851, and the microbacterium bingsonii LYY-05 is classified and named as Microbacterium bingsonii LYY-05. The microbacterium bingsonii LYY-05 provided by the invention can degrade 3 / 4 filter paper strips within 9 days, the degradation rate of corn straws within 14 days is 23.43%, and an effective microbial solution is provided for resourceful treatment of agricultural wastes such as straws.

Description

Technical Field

[0001] This invention relates to the field of microbial degradation technology, specifically to a strain of Microbacterium binae LYY-05 for degrading straw and its applications. Background Technology

[0002] Straw mainly comes from gramineous food crops (such as rice and corn) and cash crops (such as cotton and rapeseed). It is generally a dry, fibrous plant residue with a hard texture, and is a byproduct of crop harvesting. Properly treating straw to increase its usability is of great significance for environmental management and protection. Straw contains 20%–30% lignin, which combines with cellulose and hemicellulose to form a dense structure, making it difficult to degrade. Traditional physical methods typically use crushing and steam explosion to treat straw, which are not only expensive in terms of equipment but also energy-intensive. Traditional chemical degradation methods often use strong acids and alkalis for pretreatment of straw, which can easily produce byproducts that inhibit fermentation, and improper operation can leave residues that pollute the environment. Microbial degradation of straw has advantages such as safety, environmental friendliness, and low cost, making it a new approach to straw management. However, currently, there is a shortage of highly efficient bacterial strains, which cannot meet the needs of large-scale agricultural waste treatment. Therefore, screening and cultivating microbial strains with high degradation capabilities has become the key to promoting the resource utilization of straw. Summary of the Invention

[0003] This invention provides a strain of *Microbacterium bineri* LYY-05 for degrading straw and its applications. The *Microbacterium bineri* LYY-05 provided by this invention can efficiently degrade cellulosic materials, degrading 3 / 4 of a filter paper strip within 9 days and achieving a degradation rate of 23.43% for corn straw within 14 days, providing an effective microbial solution for the resource-based treatment of agricultural waste such as straw.

[0004] This invention provides a strain of *Microbacterium bineri* LYY-05 for degrading straw. This *Microbacterium bineri* LYY-05 was deposited at the China Center for Type Culture Collection on August 19, 2025, with accession number CCTCC NO: M 20251851, and is classified as follows: Microbacterium binotii LYY-05.

[0005] The *Bacillus bini* LYY-05 provided by this invention can degrade 3 / 4 of a filter paper strip within 9 days and achieve a degradation rate of 23.43% for straw within 14 days, providing an effective microbial solution for the resource utilization of agricultural waste such as straw.

[0006] The present invention also provides an LYY-05 seed culture, which is obtained by culturing the aforementioned *Bacillus bini* LYY-05.

[0007] Further, *Microbacterium bineri* LYY-05 was inoculated into 50 mL of CMC-Na medium and cultured on a shaker at 28℃~32℃ and 140r / min~160r / min for 46 h~50 h. Then, it was transferred to 50 mL of CMC-Na medium at a volume ratio of 0.5%~1.5% and cultured for another 46 h~50 h to obtain the LYY-05 seed culture.

[0008] The present invention also provides the application of the aforementioned *Microbacterium bineri* LYY-05 or the aforementioned LYY-05 seed liquid in the degradation of straw.

[0009] Further, the degradation of straw is carried out by mixing LYY-05 seed liquid with straw and then culturing it. 1 L of the culture system contains 10 mL to 30 mL of LYY-05 seed liquid and 16 g to 24 g of straw. Furthermore, the 1 L culture system also contains 0.8 g to 1.2 g of potassium dihydrogen phosphate, 0.08 g to 0.12 g of magnesium sulfate heptahydrate, 0.08 g to 0.12 g of ferrous sulfate heptahydrate, 0.008 g to 0.012 g of manganese sulfate, and 1.8 g to 2.2 g of peptone.

[0010] Furthermore, the culture temperature is 28℃~32℃.

[0011] Furthermore, the culture time is 7 to 25 days.

[0012] Furthermore, the straw is corn straw.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The *Bacillus bini* strain LYY-05 provided by this invention has a strong degradation ability on cellulose materials: in the filter paper strip degradation experiment, the LYY-05 strain can achieve more than 3 / 4 degradation of the filter paper strip within 9 days (Table 1), showing extremely high cellulase activity; in the degradation of actual agricultural waste—straw, the LYY-05 strain achieved a degradation rate of 23.43% of corn straw within 14 days (Table 2), proving its effective decomposition ability on complex natural cellulose substrates.

[0014] This invention employs microbial fermentation, completely avoiding the chemical residues, secondary pollution, and equipment corrosion problems that may arise from traditional physicochemical methods (such as strong acid or strong alkali pretreatment or steam explosion) in straw treatment, thus meeting the requirements of green environmental protection and sustainable development. Furthermore, compared to traditional methods requiring large equipment and high-temperature, high-pressure conditions, the microbial degradation process of this invention can be carried out at ambient temperature and pressure, with mild operating conditions, significantly reducing equipment investment costs and energy consumption. In addition, the biodegradation process is highly specific, unlikely to produce byproducts that inhibit subsequent fermentation processes, thus improving the potential and efficiency of straw resource utilization.

[0015] Information on the preservation of biological materials: LYY-05, referred to in this invention as *Microbacterium bineri* LYY-05, was deposited on August 19, 2025, at the China Center for Type Culture Collection (CCTCC), accession number CCTCC NO: M 20251851. The address of the depository is Wuhan University, Wuhan, China, postcode: 430072. It is classified and named as follows: Microbacterium binotii LYY-05. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 The effect of Gram staining on LYY-05 strain.

[0018] Figure 2 The colony morphology of strain LYY-05 on CMC-Na selection plates.

[0019] Figure 3 The colony morphology of strain LYY-05 on Congo red agar plates.

[0020] Figure 4 Phylogenetic tree of strain LYY-05. Detailed Implementation

[0021] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0022] Example 1: Isolation and identification of Microbacterium bini LYY-05.

[0023] I. Enrichment of bacterial strains The soil used for microbial isolation was taken from the rhizosphere soil of straw in a farmland in Suiyang County, Guizhou Province. The culture media used for enriching straw-degrading bacteria are mainly CMC-Na medium (1.57 g potassium dihydrogen phosphate trihydrate, 0.34 g potassium dihydrogen phosphate, 0.05 g calcium chloride, 0.25 g magnesium sulfate heptahydrate, 0.99 g ammonium sulfate, 10 g CMC-Na, 0.025 mg manganese sulfate monohydrate, 1 L distilled water, pH 7.0), basic straw inorganic salt medium (1.0 g potassium dihydrogen phosphate, 0.1 g magnesium sulfate heptahydrate, 0.1 g ferrous sulfate heptahydrate, 0.01 g manganese sulfate, 2 g peptone, 20 g straw powder, water to 1000 mL), CMC-Na screening medium (10 g CMC-Na, 1 g yeast extract, 20 g agar, water to 1000 mL), and CMC-Na identification medium (5.5 g CMC-Na, 0.99 g ammonium sulfate, 0.2 g magnesium sulfate heptahydrate). 2.0 g of dipotassium hydrogen phosphate, 0.5 g of sodium chloride, 0.5 g of yeast extract, 20 g of agar, and water to a final volume of 1000 mL. 50 mL of CMC-Na medium was added to a 150 mL Erlenmeyer flask and sterilized at 121℃ for 20 min. 10 g of soil was added to 50 mL of basic straw inorganic salt medium and cultured continuously with shaking at 30℃ and 150 rpm for 2 weeks. 5 mL of the culture was then added to 50 mL of the basic straw inorganic salt medium and cultured under the same conditions. After three consecutive subcultures, 50 mL of the culture was added to 50 mL of the above CMC-Na medium and cultured continuously at 30℃ and 150 rpm for 5 consecutive subcultures. When the medium became clear (indicating that the CMC-Na in the medium had been degraded and the abundance of cellulose-degrading bacteria was high), a strain enrichment was obtained for the isolation and purification of the strain.

[0024] II. Isolation and purification of strains The bacterial enrichment solution was serially diluted to 1×10⁻⁶ using 0.9% sterile physiological saline. -7The diluted solution was spread onto the above-mentioned CMC-Na identification medium and incubated at 30℃. Colony growth was observed periodically. When the colony diameter reached 2±1 mm, continuous streaking was performed until a pure strain was obtained. The pure strain was inoculated into 50 mL of the above-mentioned CMC-Na medium and cultured at 30℃ and 150 r / min for 48 h. Then, it was transferred to 50 mL of CMC-Na medium at a volume ratio of 0.5%~1.5% and cultured for another 48 h to prepare a seed culture. Under sterile conditions, 1% of the seed culture was inoculated into filter paper strip disintegration medium (ammonium sulfate 1.0 g, magnesium sulfate heptahydrate 0.5 g, dipotassium hydrogen phosphate 1.0 g, yeast extract 0.1 g, 60 1 cm × 6 cm filter paper strips, and water added to 1000 mL). Each group was divided into three replicates. After 48 h of incubation at 30℃ and 150 rpm, the degradation of the filter paper strips was observed. The results (Table 1) show that the strain was able to degrade 3 / 4 of the filter paper by day 9.

[0025] Table 1. Degradation data of the strain on filter paper strips Note: + indicates that the filter paper has softened, ++ indicates that the filter paper is 1 / 4 degraded, +++ indicates that the filter paper is 1 / 2 degraded, ++++ indicates that the filter paper is 3 / 4 degraded, and +++++ indicates that the filter paper is completely degraded.

[0026] III. Strain Identification Microscopic examination revealed that this strain was a Gram-positive bacterium, with short rod-shaped cells. Figure 1 On CMC-Na differential medium, its colonies are irregularly shaped, 1.5 ± 0.5 mm in diameter, with smooth edges, a smooth and moist surface, no protrusions, and a translucent, pale yellow color (see...). Figure 2 After incubation at 30℃ for 3 days on CMC-Na screening plates, 0.1% Congo red staining solution was added for staining for 15 min, followed by destaining with 1 mol / L NaCl solution for 2 min. The calculated ratio of the hydrolysis zone diameter D to the colony diameter d reached 2.573, indicating that this strain has a strong ability to degrade cellulose (Table 2 and...). Figure 3 The 16S rDNA of this strain (SEQ ID NO: 1) was amplified using the universal primers 27F and 1492r. The sequence length was 755 bp. The strain was sent to Sangon Biotech (Shanghai) Co., Ltd. for identification and sequencing.

[0027] Constructing a phylogenetic tree based on 16S rDNA sequences ( Figure 4 The results showed that this strain was related to known microbes. Microbacterium binotii The strain showed the highest homology and was identified as Microbes bingerii, named Microbes bingerii LYY-05.

[0028] Table 2 Data of the hydrolysis zone and colony diameter of strains on Congo red screening plates SEQ ID NO: 1: CGGGTAGCCGGCCCTGAGAGGGTGACCGGCCACACT GGGACTGAGACACGGCCCAGACTCGTACGGGAGGCAGCAGTGGGGAATA TTGCACAATGGGCGAAAGCCTGATGCAGCAACGCCGCGTGAGGGATGAC GGCCTTCGGGTTGTAAACCTCTTTTAGCAAGGAAGAAGCGAAAGTGACG GTACTTGCAGAAAAAGCGCCGGCTAACTACGTGCCAGCAGCCGCGGTAAT ACGTAGGGCGCAAGCGTTATCCGGAATTATTGGGCGTAAAGAGCTCGTAG GCGGTTTGTCGCGTCTGCTGTGAAAACTGGAGGCTCAACCTCCAGCCTGC AGTGGGTACGGGCAGACTAGAGTGCGGTAGGGGAGATTGGAATTCCTGGT GTAGCGGTGGAATGCGCAGATATCAGGAGGAACACCGATGGCGAAGGCA GATCTCTGGGCCGTAACTGACGCTGAGGAGCGAAAGGGTGGGGAGCAAA CAGGCTTAGATACCCTGGTAGTCCACCCCGTAAACGTTGGGAACTAGTTG TGGGGACCATTCCACGGTTTCCGTGACGCAGCTAACGCATTAAGTTCCCC GCCTGGGGAGTACGGCCGCAAGGCTAAAACTCAAAGGAATTGACGGGGA CCCGCACAAGCGGCGGAGCATGCGGATTAATTCGATGCAACGCGAAGAA CCTTACCAAGGCTTGACATATACGAGAACGCTGCAGAAATGTAGAACTCT TTGGACACTCGTATACAGGTGGTGCA.

[0029] Example 2: The degradation effect of Microbacterium bineri LYY-05 on straw.

[0030] The LYY-05 seed culture was transferred at a 2% (v / v) ratio to 50 mL of straw liquid culture medium (1.0 g potassium dihydrogen phosphate, 0.1 g magnesium sulfate heptahydrate, 0.1 g ferrous sulfate heptahydrate, 0.01 g manganese sulfate, 2 g peptone, water added to 1000 mL, and 1 g of corn straw fragments (2 ± 1 cm) added to each 50 mL culture medium). The medium was cultured at 30℃ and 150 r / min for 14 days to allow the fungus LYY-02 to degrade the corn straw fragments. After cultivation, the residue was filtered through a 100-mesh filter and collected, then dried in an oven at 85℃ until constant weight. The results (Table 2) showed that the LYY-05 strain could effectively degrade straw, with a degradation rate of 23.43% for corn straw in the straw liquid culture medium.

[0031] Table 3. Degradation data of straw by strain LYY-05 Although preferred embodiments of the invention have been described, those skilled in the art, once they have learned the basic inventive concept, can make other changes and modifications to these embodiments.

[0032] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A strain of *Microbacterium bineri* LYY-05 for degrading straw, characterized in that, The *Microbacterium bineri* LYY-05 was deposited at the China Center for Type Culture Collection (CCTCC) on August 19, 2025, with accession number CCTCC NO: M 20251851, and classified as follows: Microbacterium binotii LYY-05.

2. A LYY-05 seed liquid, characterized in that, The LYY-05 seed culture was obtained by culturing the *Bacillus bini* LYY-05 as described in claim 1.

3. The LYY-05 seed liquid according to claim 2, characterized in that, The *Bacillus bini* LYY-05 was inoculated into CMC-Na medium and cultured on a shaker at 28℃~32℃ and 140 r / min~160 r / min for 46 h~50 h. Then, it was transferred to CMC-Na medium at a volume ratio of 0.5%~1.5% and cultured for another 46 h~50 h to obtain the LYY-05 seed culture.

4. The application of the *Bacillus bini* LYY-05 as described in claim 1 or the LYY-05 seed liquid as described in claims 2-3 in the degradation of straw.

5. The application according to claim 4, characterized in that, The degradation of straw is carried out by mixing LYY-05 seed liquid with straw and then culturing it. 1 L of culture system contains 10 mL to 30 mL of LYY-05 seed liquid and 16 g to 24 g of straw.

6. The application according to claim 5, characterized in that, The 1 L culture system also contains 0.8 g to 1.2 g of potassium dihydrogen phosphate, 0.08 g to 0.12 g of magnesium sulfate heptahydrate, 0.08 g to 0.12 g of ferrous sulfate heptahydrate, 0.008 g to 0.012 g of manganese sulfate, and 1.8 g to 2.2 g of peptone.

7. The application according to claim 5, characterized in that, The culture temperature is 28℃~32℃.

8. The application according to claim 5, characterized in that, The culture time is 7 to 25 days.

9. The application according to claim 5, characterized in that, The straw includes corn stalks.

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