Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis
Abstract Background Seleno-methylselenocysteine (SeMCys) is an effective component of selenium supplementation with anti-carcinogenic potential that can ameliorate neuropathology and cognitive deficits. In a previous study, a SeMCys producing strain of Bacillus subtilis GBACB was generated by releas...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2023-10-01
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| Series: | Microbial Cell Factories |
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| Online Access: | https://doi.org/10.1186/s12934-023-02203-1 |
| _version_ | 1797450986911956992 |
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| author | Xian Yin Meiyi Zhao Yu Zhou Hulin Yang Yonghong Liao Fenghuan Wang |
| author_facet | Xian Yin Meiyi Zhao Yu Zhou Hulin Yang Yonghong Liao Fenghuan Wang |
| author_sort | Xian Yin |
| collection | DOAJ |
| description | Abstract Background Seleno-methylselenocysteine (SeMCys) is an effective component of selenium supplementation with anti-carcinogenic potential that can ameliorate neuropathology and cognitive deficits. In a previous study, a SeMCys producing strain of Bacillus subtilis GBACB was generated by releasing feedback inhibition by overexpression of cysteine-insensitive serine O-acetyltransferase, enhancing the synthesis of S-adenosylmethionine as methyl donor by overexpression of S-adenosylmethionine synthetase, and expressing heterologous selenocysteine methyltransferase. In this study, we aimed to improve GBACB SeMCys production by synthesizing methylmethionine as a donor to methylate selenocysteine and by inhibiting the precursor degradation pathway. Results First, the performance of three methionine S-methyltransferases that provide methylmethionine as a methyl donor for SeMCys production was determined. Integration of the NmMmt gene into GBACB improved SeMCys production from 20.7 to 687.4 μg/L. Next, the major routes for the degradation of selenocysteine, which is the precursor of SeMCys, were revealed by comparing selenocysteine hyper-accumulating and non-producing strains at the transcriptional level. The iscSB knockout strain doubled SeMCys production. Moreover, deleting sdaA, which is responsible for the degradation of serine as a precursor of selenocysteine, enhanced SeMCys production to 4120.3 μg/L. Finally, the culture conditions in the flasks were optimized. The strain was tolerant to higher selenite content in the liquid medium and the titer of SeMCys reached 7.5 mg/L. Conclusions The significance of methylmethionine as a methyl donor for SeMCys production in B. subtilis is reported, and enhanced precursor supply facilitates SeMCys synthesis. The results represent the highest SeMCys production to date and provide insight into Se metabolism. |
| first_indexed | 2024-03-09T14:48:26Z |
| format | Article |
| id | doaj.art-83ab4d4534884daea37c51c2e2427934 |
| institution | Directory Open Access Journal |
| issn | 1475-2859 |
| language | English |
| last_indexed | 2024-03-09T14:48:26Z |
| publishDate | 2023-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Microbial Cell Factories |
| spelling | doaj.art-83ab4d4534884daea37c51c2e24279342023-11-26T14:37:48ZengBMCMicrobial Cell Factories1475-28592023-10-0122111110.1186/s12934-023-02203-1Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilisXian Yin0Meiyi Zhao1Yu Zhou2Hulin Yang3Yonghong Liao4Fenghuan Wang5Key Laboratory of Geriatric Nutrition and Health (Ministry of Education), Beijing Technology and Business UniversityKey Laboratory of Geriatric Nutrition and Health (Ministry of Education), Beijing Technology and Business UniversityKey Laboratory of Geriatric Nutrition and Health (Ministry of Education), Beijing Technology and Business UniversityKey Laboratory of Geriatric Nutrition and Health (Ministry of Education), Beijing Technology and Business UniversityKey Laboratory of Geriatric Nutrition and Health (Ministry of Education), Beijing Technology and Business UniversityKey Laboratory of Geriatric Nutrition and Health (Ministry of Education), Beijing Technology and Business UniversityAbstract Background Seleno-methylselenocysteine (SeMCys) is an effective component of selenium supplementation with anti-carcinogenic potential that can ameliorate neuropathology and cognitive deficits. In a previous study, a SeMCys producing strain of Bacillus subtilis GBACB was generated by releasing feedback inhibition by overexpression of cysteine-insensitive serine O-acetyltransferase, enhancing the synthesis of S-adenosylmethionine as methyl donor by overexpression of S-adenosylmethionine synthetase, and expressing heterologous selenocysteine methyltransferase. In this study, we aimed to improve GBACB SeMCys production by synthesizing methylmethionine as a donor to methylate selenocysteine and by inhibiting the precursor degradation pathway. Results First, the performance of three methionine S-methyltransferases that provide methylmethionine as a methyl donor for SeMCys production was determined. Integration of the NmMmt gene into GBACB improved SeMCys production from 20.7 to 687.4 μg/L. Next, the major routes for the degradation of selenocysteine, which is the precursor of SeMCys, were revealed by comparing selenocysteine hyper-accumulating and non-producing strains at the transcriptional level. The iscSB knockout strain doubled SeMCys production. Moreover, deleting sdaA, which is responsible for the degradation of serine as a precursor of selenocysteine, enhanced SeMCys production to 4120.3 μg/L. Finally, the culture conditions in the flasks were optimized. The strain was tolerant to higher selenite content in the liquid medium and the titer of SeMCys reached 7.5 mg/L. Conclusions The significance of methylmethionine as a methyl donor for SeMCys production in B. subtilis is reported, and enhanced precursor supply facilitates SeMCys synthesis. The results represent the highest SeMCys production to date and provide insight into Se metabolism.https://doi.org/10.1186/s12934-023-02203-1Seleno-methylselenocysteineMethylmethionineSelenocysteineSerineBacillus subtilis |
| spellingShingle | Xian Yin Meiyi Zhao Yu Zhou Hulin Yang Yonghong Liao Fenghuan Wang Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis Microbial Cell Factories Seleno-methylselenocysteine Methylmethionine Selenocysteine Serine Bacillus subtilis |
| title | Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis |
| title_full | Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis |
| title_fullStr | Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis |
| title_full_unstemmed | Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis |
| title_short | Optimized methyl donor and reduced precursor degradation pathway for seleno-methylselenocysteine production in Bacillus subtilis |
| title_sort | optimized methyl donor and reduced precursor degradation pathway for seleno methylselenocysteine production in bacillus subtilis |
| topic | Seleno-methylselenocysteine Methylmethionine Selenocysteine Serine Bacillus subtilis |
| url | https://doi.org/10.1186/s12934-023-02203-1 |
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