Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation
Abstract Background Molasses is a wildly used feedstock for fermentation, but it also poses a severe wastewater-disposal problem worldwide. Recently, the wastewater from yeast molasses fermentation is being processed into fulvic acid (FA) powder as a fertilizer for crops, but it consequently induces...
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| Format: | Article |
| Language: | English |
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BMC
2020-10-01
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| Series: | Biotechnology for Biofuels |
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| Online Access: | http://link.springer.com/article/10.1186/s13068-020-01818-5 |
| _version_ | 1818263062945202176 |
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| author | Yazhou Li Jianghan Wang Na Liu Luxin Ke Xiuyun Zhao Gaofu Qi |
| author_facet | Yazhou Li Jianghan Wang Na Liu Luxin Ke Xiuyun Zhao Gaofu Qi |
| author_sort | Yazhou Li |
| collection | DOAJ |
| description | Abstract Background Molasses is a wildly used feedstock for fermentation, but it also poses a severe wastewater-disposal problem worldwide. Recently, the wastewater from yeast molasses fermentation is being processed into fulvic acid (FA) powder as a fertilizer for crops, but it consequently induces a problem of soil acidification after being directly applied into soil. In this study, the low-cost FA powder was bioconverted into a value-added product of γ-PGA by a glutamate-independent producer of Bacillus velezensis GJ11. Results FA power could partially substitute the high-cost substrates such as sodium glutamate and citrate sodium for producing γ-PGA. With FA powder in the fermentation medium, the amount of sodium glutamate and citrate sodium used for producing γ-PGA were both decreased around one-third. Moreover, FA powder could completely substitute Mg2+, Mn2+, Ca2+, and Fe3+ in the fermentation medium for producing γ-PGA. In the optimized medium with FA powder, the γ-PGA was produced at 42.55 g/L with a productivity of 1.15 g/(L·h), while only 2.87 g/L was produced in the medium without FA powder. Hydrolyzed γ-PGA could trigger induced systemic resistance (ISR), e.g., H2O2 accumulation and callose deposition, against the pathogen’s infection in plants. Further investigations found that the ISR triggered by γ-PGA hydrolysates was dependent on the ethylene (ET) signaling and nonexpressor of pathogenesis-related proteins 1 (NPR1). Conclusions To our knowledge, this is the first report to use the industry waste, FA powder, as a sustainable substrate for microbial synthesis of γ-PGA. This bioprocess can not only develop a new way to use FA powder as a cheap feedstock for producing γ-PGA, but also help to reduce pollution from the wastewater of yeast molasses fermentation. |
| first_indexed | 2024-12-12T19:13:03Z |
| format | Article |
| id | doaj.art-2f609ddecb734fb7a6b3c3ed0ab42b3d |
| institution | Directory Open Access Journal |
| issn | 1754-6834 |
| language | English |
| last_indexed | 2024-12-12T19:13:03Z |
| publishDate | 2020-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Biotechnology for Biofuels |
| spelling | doaj.art-2f609ddecb734fb7a6b3c3ed0ab42b3d2022-12-22T00:14:48ZengBMCBiotechnology for Biofuels1754-68342020-10-0113111710.1186/s13068-020-01818-5Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentationYazhou Li0Jianghan Wang1Na Liu2Luxin Ke3Xiuyun Zhao4Gaofu Qi5College of Life Science and Technology, Huazhong Agricultural UniversityCollege of Life Science and Technology, Huazhong Agricultural UniversityCollege of Life Science and Technology, Huazhong Agricultural UniversityDepartment of Genetics and Genome Sciences, School of Medicine, Case Western Reserve UniversityCollege of Life Science and Technology, Huazhong Agricultural UniversityCollege of Life Science and Technology, Huazhong Agricultural UniversityAbstract Background Molasses is a wildly used feedstock for fermentation, but it also poses a severe wastewater-disposal problem worldwide. Recently, the wastewater from yeast molasses fermentation is being processed into fulvic acid (FA) powder as a fertilizer for crops, but it consequently induces a problem of soil acidification after being directly applied into soil. In this study, the low-cost FA powder was bioconverted into a value-added product of γ-PGA by a glutamate-independent producer of Bacillus velezensis GJ11. Results FA power could partially substitute the high-cost substrates such as sodium glutamate and citrate sodium for producing γ-PGA. With FA powder in the fermentation medium, the amount of sodium glutamate and citrate sodium used for producing γ-PGA were both decreased around one-third. Moreover, FA powder could completely substitute Mg2+, Mn2+, Ca2+, and Fe3+ in the fermentation medium for producing γ-PGA. In the optimized medium with FA powder, the γ-PGA was produced at 42.55 g/L with a productivity of 1.15 g/(L·h), while only 2.87 g/L was produced in the medium without FA powder. Hydrolyzed γ-PGA could trigger induced systemic resistance (ISR), e.g., H2O2 accumulation and callose deposition, against the pathogen’s infection in plants. Further investigations found that the ISR triggered by γ-PGA hydrolysates was dependent on the ethylene (ET) signaling and nonexpressor of pathogenesis-related proteins 1 (NPR1). Conclusions To our knowledge, this is the first report to use the industry waste, FA powder, as a sustainable substrate for microbial synthesis of γ-PGA. This bioprocess can not only develop a new way to use FA powder as a cheap feedstock for producing γ-PGA, but also help to reduce pollution from the wastewater of yeast molasses fermentation.http://link.springer.com/article/10.1186/s13068-020-01818-5MolassesFulvic acid powderPoly-γ-glutamic acid (γ-PGA)Bacillus velezensisInduced systemic resistance (ISR)Ethylene (ET) signaling |
| spellingShingle | Yazhou Li Jianghan Wang Na Liu Luxin Ke Xiuyun Zhao Gaofu Qi Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation Biotechnology for Biofuels Molasses Fulvic acid powder Poly-γ-glutamic acid (γ-PGA) Bacillus velezensis Induced systemic resistance (ISR) Ethylene (ET) signaling |
| title | Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation |
| title_full | Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation |
| title_fullStr | Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation |
| title_full_unstemmed | Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation |
| title_short | Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation |
| title_sort | microbial synthesis of poly γ glutamic acid γ pga with fulvic acid powder the waste from yeast molasses fermentation |
| topic | Molasses Fulvic acid powder Poly-γ-glutamic acid (γ-PGA) Bacillus velezensis Induced systemic resistance (ISR) Ethylene (ET) signaling |
| url | http://link.springer.com/article/10.1186/s13068-020-01818-5 |
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