KR-20260062388-A - A complex microbial preparation capable of decomposing polylactic acid, and composts produced thereof

Abstract

The present invention relates to a composite microbial agent with excellent PLA degradation ability. It has been confirmed that the PLA-degrading composite microbial agent according to the present invention can rapidly and effectively degrade PLA using it as a carbon source, and can produce high-quality compost by composting livestock waste. Therefore, it can be usefully utilized for environmental protection and/or agriculture through PLA degradation.

Inventors

• 김수기
• 신재형
• 왕옌칭

Assignees

• 건국대학교 산학협력단

Dates

Publication Date

20260507

Application Date

20241029

Claims (14)

1. A composite microbial preparation for degrading biodegradable polymers comprising a strain selected from the group consisting of Alcaligenes sp, Rhodococcus sp, LysiniBacillus sp, Bacillus sp , Glutamicibacter sp, Cupriavidus sp, Streptomyces sp, Arthrobacter sp, and combinations thereof.
2. In Article 1, A composite microbial preparation for degrading biodegradable polymers, wherein the above-mentioned biodegradable polymer is one or more selected from the group consisting of PLA (poly lactic acid), PBS (poly butylene succinate), PBSA (poly butylene succinate adipate), PBAT (poly butylene adipate-co-terephthalate), PCL (poly(caprolactone)), PHA (poly(hydroxyalkano ates)), and PGA (poly(glycolic acid)).
3. In Article 1, The above-mentioned complex microbial preparation is a complex microbial preparation for degrading biodegradable polymers, which was deposited under accession number KCTC19220P.
4. A composition for degrading biodegradable polymers comprising a complex microbial agent according to claim 1.
5. A kit for degrading biodegradable polymers comprising a complex microbial preparation according to claim 1.
6. A method for degrading a biodegradable polymer, comprising the step of treating a biodegradable polymer or a contaminated area containing said biodegradable polymer with a composite microbial agent according to claim 1.
7. A complex microbial preparation for composting livestock waste comprising a strain selected from the group consisting of Alcaligenes sp, Rhodococcus sp, LysiniBacillus sp, Bacillus sp , Glutamicibacter sp, Cupriavidus sp, Streptomyces sp, Arthrobacter sp, and combinations thereof.
8. In Article 7, The above complex microbial preparation is a complex microbial preparation for the composting of livestock waste, deposited under accession number KCTC19220P.
9. A composition for composting livestock waste comprising a complex microbial agent for composting livestock waste according to Clause 7.
10. In Article 9, A composition for composting livestock waste, wherein the above composition further comprises one or more biodegradable polymers selected from the group consisting of PLA (poly lactic acid), PBS (poly butylene succinate), PBSA (poly butylene succinate adipate), PBAT (poly butylene adipate-co-terephthalate), PCL (poly(caprolactone)), PHA (poly(hydroxyalkano ates)), and PGA (poly(glycolic acid)).
11. A kit for composting livestock waste comprising a complex microbial preparation for composting livestock waste pursuant to Clause 7.
12. A method for composting livestock waste, comprising the step of treating the livestock waste with a complex microbial agent for composting according to claim 7.
13. In Paragraph 12, A method for composting livestock waste, wherein the above livestock waste contains a biodegradable polymer.
14. Step 1, treating livestock waste with a complex microbial agent for composting pursuant to Paragraph 7; and A method for composting livestock waste, comprising the step of treating livestock waste treated with the above-mentioned composite microbial agent for composting with a biodegradable polymer.

Description

A complex microbial preparation capable of decomposing polylactic acid and composts produced thereof The present invention relates to a complex microbial preparation capable of decomposing polylactic acid and a method for producing compost using the same. While plastic, widely used worldwide, offers excellent convenience, it is a serious cause of environmental pollution due to the waste generated after use. Various alternatives are emerging to replace these high-molecular polymers, one of which is bioplastic, known as eco-friendly plastic. Bioplastics are polymers manufactured using biomass, a renewable material, as a raw material. Generally, they are classified into biodegradable plastics and biomass-based plastics depending on the biomass content. Biodegradable plastics are further divided into biodegradable biomass plastics, such as polylactic acid (PLA) and polyglycolic acid (PGA), and biodegradable petroleum-based plastics, such as polycaprolactone (PCL), depending on whether they are made from biomass or petroleum. PCL and PLA, known as representative biodegradable polymers, are known to take a long time to decompose in nature, depending on the content and processing conditions of the manufactured product. In particular, PLA is known to take a considerable amount of time to begin decomposition within the soil. While various microorganisms involved in the degradation of PCL and PLA have been reported abroad, in Korea, Pseudozyma jejuensis, a yeast belonging to the Basidiomycota, has been reported to degrade PCL (Seo et al., 2007), but there is a complete lack of research on other fungi known to be able to degrade PCL or PLA. Accordingly, the inventors of the present invention have developed a complex microbial agent capable of efficiently decomposing PLA and provide high-quality compost produced through this agent. Figure 1 is a result showing the characteristics of a strain having PLA degradation ability included in the PLA degradation complex microbial preparation of the present invention. In Figure 1, "-" indicates no effect, and "+", "++", and "+++" indicate that the effect gradually increases as the number of "+" symbols increases. Figure 2 shows the results of the characteristics of the composting-promoting strain included in the PLA-degrading complex microbial preparation of the present invention. In Figure 2, "-" indicates no effect, and "+", "++", and "+++" indicate that the effect gradually increases as the number of "+" symbols increases. Figure 3 shows the results of comparing the growth of strains with PLA degradation ability in BMM agar media with different carbon sources. In Figure 3, "-" indicates no effect, "±" indicates no significant effect, and "+", "++", and "+++" indicate that the effect gradually increases as the number of "+" symbols increases. Figure 4 shows the results of comparing the growth of strains with PLA degradation ability in BMM liquid media with different carbon sources. Figure 5 is a graph of the result of Figure 4 above. Figure 6 shows the results of checking the air and compost pile temperatures during the composting period using the PLA-degrading complex microbial agent of the present invention. In Figure 6, AT represents the average temperature, LWT represents the lowest temperature, C represents the control group, and T represents the treatment group. Figure 7 shows the results of confirming the change in moisture content of compost during the composting period using the PLA-degrading complex microbial agent of the present invention. In Figure 7, C represents the control group and T represents the treatment group. Figure 8 shows the results of confirming the change in pH of the compost during the composting period using the PLA-degrading complex microbial agent of the present invention. In Figure 8, C represents the control group and T represents the treatment group. Figure 9 shows the results of confirming the change in electrical conductivity values of compost during the composting period using the PLA-degrading complex microbial agent of the present invention. In Figure 9, C represents the control group and T represents the treatment group. Additionally, '**' indicates a significance level p < 0.01 and '***' indicates a significance level p < 0.001. Figure 10 shows the results of confirming the change in nutrient content of compost during the composting period using the PLA-degrading complex microbial agent of the present invention. In Figure 10, C represents the control group and T represents the treatment group. Figure 11 shows the results of confirming the weight change (A) and degree of decomposition (B) of PLA during a composting period of 6 months using the PLA decomposition complex microbial agent of the present invention. In Figure 11, the decomposition rate of PLA was calculated based on the average weight value of PLA particles at each stage. Figure 12 is the result of visually confirming the change in the amount of PLA during the 6-month composti