A Deep-Sea Bacterium Is Capable of Degrading Polyurethane
ABSTRACT Plastic wastes have been recognized as the most common and durable marine contaminants, which are not only found in the shallow water, but also on the sea floor. However, whether deep-sea microorganisms have evolved the capability of degrading plastic remains elusive. In this study, a deep-...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2023-06-01
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| Series: | Microbiology Spectrum |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/spectrum.00073-23 |
| _version_ | 1797803398052970496 |
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| author | Zhi Gui Guangchao Liu Xin Liu Ruining Cai Rui Liu Chaomin Sun |
| author_facet | Zhi Gui Guangchao Liu Xin Liu Ruining Cai Rui Liu Chaomin Sun |
| author_sort | Zhi Gui |
| collection | DOAJ |
| description | ABSTRACT Plastic wastes have been recognized as the most common and durable marine contaminants, which are not only found in the shallow water, but also on the sea floor. However, whether deep-sea microorganisms have evolved the capability of degrading plastic remains elusive. In this study, a deep-sea bacterium Bacillus velezensis GUIA was found to be capable of degrading waterborne polyurethane. Transcriptomic analysis showed that the supplement of waterborne polyurethane upregulated the expression of many genes related to spore germination, indicating that the presence of plastic had effects on the growth of strain GUIA. In addition, the supplement of waterborne polyurethane also evidently upregulated the expressions of many genes encoding lipase, protease, and oxidoreductase. Liquid chromatography-mass spectrometry (LC-MS) results showed that potential enzymes responsible for plastic degradation in strain GUIA were identified as oxidoreductase, protease, and lipase, which was consistent with the transcriptomic analysis. In combination of in vitro expression and degradation assays as well as Fourier transform infrared (FTIR) analysis, we demonstrated that the oxidoreductase Oxr-1 of strain GUIA was the key degradation enzyme toward waterborne polyurethane. Moreover, the oxidoreductase Oxr-1 was also shown to degrade the biodegradable polybutylene adipate terephthalate (PBAT) film indicating its wide application potential. IMPORTANCE The widespread and indiscriminate disposal of plastics inevitably leads to environmental pollution. The secondary pollution by current landfill and incineration methods causes serious damage to the atmosphere, land, and rivers. Therefore, microbial degradation is an ideal way to solve plastic pollution. Recently, the marine environment is becoming a hot spot to screen microorganisms possessing potential plastic degradation capabilities. In this study, a deep-sea Bacillus strain was shown to degrade both waterborne polyurethane and biodegradable PBAT film. The FAD-binding oxidoreductase Oxr-1 was demonstrated to be the key enzyme mediating plastic degradation. Our study not only provided a good candidate for developing bio-products toward plastic degradation but also paved a way to investigate the carbon cycle mediated by plastic degradation in deep-sea microorganisms. |
| first_indexed | 2024-03-13T05:20:11Z |
| format | Article |
| id | doaj.art-799a789d249e460aabd2d544e3b2f50f |
| institution | Directory Open Access Journal |
| issn | 2165-0497 |
| language | English |
| last_indexed | 2024-03-13T05:20:11Z |
| publishDate | 2023-06-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | Microbiology Spectrum |
| spelling | doaj.art-799a789d249e460aabd2d544e3b2f50f2023-06-15T13:18:33ZengAmerican Society for MicrobiologyMicrobiology Spectrum2165-04972023-06-0111310.1128/spectrum.00073-23A Deep-Sea Bacterium Is Capable of Degrading PolyurethaneZhi Gui0Guangchao Liu1Xin Liu2Ruining Cai3Rui Liu4Chaomin Sun5Key Lab of Plant Biotechnology in Universities of Shandong Province, College of Life Science, Qingdao Agricultural University, Qingdao, ChinaKey Lab of Plant Biotechnology in Universities of Shandong Province, College of Life Science, Qingdao Agricultural University, Qingdao, ChinaKey Lab of Plant Biotechnology in Universities of Shandong Province, College of Life Science, Qingdao Agricultural University, Qingdao, ChinaCAS and Shandong Province Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, ChinaCAS and Shandong Province Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, ChinaCAS and Shandong Province Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, ChinaABSTRACT Plastic wastes have been recognized as the most common and durable marine contaminants, which are not only found in the shallow water, but also on the sea floor. However, whether deep-sea microorganisms have evolved the capability of degrading plastic remains elusive. In this study, a deep-sea bacterium Bacillus velezensis GUIA was found to be capable of degrading waterborne polyurethane. Transcriptomic analysis showed that the supplement of waterborne polyurethane upregulated the expression of many genes related to spore germination, indicating that the presence of plastic had effects on the growth of strain GUIA. In addition, the supplement of waterborne polyurethane also evidently upregulated the expressions of many genes encoding lipase, protease, and oxidoreductase. Liquid chromatography-mass spectrometry (LC-MS) results showed that potential enzymes responsible for plastic degradation in strain GUIA were identified as oxidoreductase, protease, and lipase, which was consistent with the transcriptomic analysis. In combination of in vitro expression and degradation assays as well as Fourier transform infrared (FTIR) analysis, we demonstrated that the oxidoreductase Oxr-1 of strain GUIA was the key degradation enzyme toward waterborne polyurethane. Moreover, the oxidoreductase Oxr-1 was also shown to degrade the biodegradable polybutylene adipate terephthalate (PBAT) film indicating its wide application potential. IMPORTANCE The widespread and indiscriminate disposal of plastics inevitably leads to environmental pollution. The secondary pollution by current landfill and incineration methods causes serious damage to the atmosphere, land, and rivers. Therefore, microbial degradation is an ideal way to solve plastic pollution. Recently, the marine environment is becoming a hot spot to screen microorganisms possessing potential plastic degradation capabilities. In this study, a deep-sea Bacillus strain was shown to degrade both waterborne polyurethane and biodegradable PBAT film. The FAD-binding oxidoreductase Oxr-1 was demonstrated to be the key enzyme mediating plastic degradation. Our study not only provided a good candidate for developing bio-products toward plastic degradation but also paved a way to investigate the carbon cycle mediated by plastic degradation in deep-sea microorganisms.https://journals.asm.org/doi/10.1128/spectrum.00073-23polyurethanedegradationdeep seaBacillusoxidoreductase |
| spellingShingle | Zhi Gui Guangchao Liu Xin Liu Ruining Cai Rui Liu Chaomin Sun A Deep-Sea Bacterium Is Capable of Degrading Polyurethane Microbiology Spectrum polyurethane degradation deep sea Bacillus oxidoreductase |
| title | A Deep-Sea Bacterium Is Capable of Degrading Polyurethane |
| title_full | A Deep-Sea Bacterium Is Capable of Degrading Polyurethane |
| title_fullStr | A Deep-Sea Bacterium Is Capable of Degrading Polyurethane |
| title_full_unstemmed | A Deep-Sea Bacterium Is Capable of Degrading Polyurethane |
| title_short | A Deep-Sea Bacterium Is Capable of Degrading Polyurethane |
| title_sort | deep sea bacterium is capable of degrading polyurethane |
| topic | polyurethane degradation deep sea Bacillus oxidoreductase |
| url | https://journals.asm.org/doi/10.1128/spectrum.00073-23 |
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