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Yan C, Tao Y, Fan J, Dai J, Li S, Huang Q, Zhou R. Generation and characterization of two acid-resistant macrocin O-methyltransferase variants with a higher enzyme activity at 30 °C from Streptomyces fradiae. Comput Struct Biotechnol J 2024; 23:3232-3240. [PMID: 39257526 PMCID: PMC11384511 DOI: 10.1016/j.csbj.2024.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 08/07/2024] [Accepted: 08/20/2024] [Indexed: 09/12/2024] Open
Abstract
Tylosin is an important macrolide antibiotic produced by Streptomyces fradiae. In the biosynthesis of tylosin, macrocin O-methyltransferase TylF catalyzes the conversion of the side-product tylosin C (macrocin) to the primary component tylosin A (C/A conversion). This conversion is the rate-limiting step in the biosynthesis of tylosin, and affects the quality of the end product. To find a high activity and environment-adapted TylF enzyme, a TylF variant pool has been constructed via protein evolution approach in our previous study (Fan et al., 2023 [41]). In this study, the TylF variants with higher C/A conversion rates were expressed in E. coli and purified. The variants TylFY139F, TylFQ138H, F232Y and TylFT36S, V54A were shown to have a higher C/A conversion rate at 30 °C than that of TylF at 38 °C. Moreover, they had a greater acid resistance and showed more adaptable to the pH change during fermentation. Further protein structural and substrate-binding affinity analyses revealed that the T36S, V54A, Q138H, Y139F, and F232Y mutations enlarged the volume of the substrate-binding pocket, thereby increasing the affinity of enzyme variants for their substrates of SAM and macrocin, and decreasing the inhibition of SAH. Three of the TylF variants were overexpressed in the industrial tylosin-producing S. fradiae strain, and the recombinant strains showed the highest C/A conversion at 30 °C without heating up to 38 °C during the last 24 h of fermentation. This is of great energy-saving significance for tylosin industrial production.
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Affiliation(s)
- Chaoyue Yan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Yujun Tao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Jingyan Fan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou 311300, China
| | - Jun Dai
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The HZAU-HVSEN Institute, Wuhan 430060, China
| | - Shuo Li
- The HZAU-HVSEN Institute, Wuhan 430060, China
| | - Qi Huang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan 430070, China
- The Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan 430070, China
- The Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
- The HZAU-HVSEN Institute, Wuhan 430060, China
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Fan J, Yao Z, Yan C, Hao M, Dai J, Zou W, Ni M, Li T, Li L, Li S, Liu J, Huang Q, Zhou R. Discovery of a highly efficient TylF methyltransferase via random mutagenesis for improving tylosin production. Comput Struct Biotechnol J 2023; 21:2759-2766. [PMID: 37181661 PMCID: PMC10172623 DOI: 10.1016/j.csbj.2023.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/11/2023] [Accepted: 04/11/2023] [Indexed: 05/16/2023] Open
Abstract
Macrolides are currently a class of extensively used antibiotics in human and animal medicine. Tylosin is not only one of the most important veterinary macrolides but also an indispensable material for the bio- and chemo-synthesis of new generations of macrolide antibiotics. Thus, improving its production yield is of great value. As the key rate-limiting enzyme catalyzing the terminal step of tylosin biosynthesis in Streptomyces fradiae (S. fradiae), TylF methyltransferase's catalytic activity directly affects tylosin yield. In this study, a tylF mutant library of S. fradiae SF-3 was constructed based on error-prone PCR technology. After two steps of screening in 24-well plates and conical flask fermentation and enzyme activity assay, a mutant strain was identified with higher TylF activity and tylosin yield. The mutation of tyrosine to phenylalanine is localized at the 139th amino acid residue on TylF (TylFY139F), and protein structure simulations demonstrated that this mutation changed the protein structure of TylF. Compared with wild-type protein TylF, TylFY139F exhibited higher enzymatic activity and thermostability. More importantly, the Y139 residue in TylF is a previously unidentified position required for TylF activity and tylosin production in S. fradiae, indicating the further potential to engineer the enzyme. These findings provide helpful information for the directed molecular evolution of this important enzyme and the genetic modification of tylosin-producing bacteria.
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Affiliation(s)
- Jingyan Fan
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhiming Yao
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Chaoyue Yan
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Meilin Hao
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Jun Dai
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Provincial Bioengineering Technology Research Center for Animal Health Products, Yingcheng 432400, China
- The HZAU-HVSEN Research Institute, Wuhan 430042, China
| | - Wenjin Zou
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Minghui Ni
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Tingting Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Lu Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science and Technology of China), Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
| | - Shuo Li
- Hubei Provincial Bioengineering Technology Research Center for Animal Health Products, Yingcheng 432400, China
- The HZAU-HVSEN Research Institute, Wuhan 430042, China
| | - Jie Liu
- Hubei Provincial Bioengineering Technology Research Center for Animal Health Products, Yingcheng 432400, China
- The HZAU-HVSEN Research Institute, Wuhan 430042, China
| | - Qi Huang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science and Technology of China), Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
- Correspondence to: College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Rui Zhou
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science and Technology of China), Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
- The HZAU-HVSEN Research Institute, Wuhan 430042, China
- Correspondence to: College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
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Cheng N, Wang B, Wu P, Lee X, Xing Y, Chen M, Gao B. Adsorption of emerging contaminants from water and wastewater by modified biochar: A review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 273:116448. [PMID: 33486256 DOI: 10.1016/j.envpol.2021.116448] [Citation(s) in RCA: 210] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/30/2020] [Accepted: 01/04/2021] [Indexed: 05/11/2023]
Abstract
Emerging contaminants (ECs), a group of relatively low-concentration but high-toxicity pollutants in the environment, have attracted widespread attention in recent years. These trace pollutants can be enriched in organisms and finally transferred to human bodies, posing a potential hazard to public health. Biochar, a low-cost and high-efficiency adsorbent, has been used to treat ECs in water. However, due to certain limitations of pristine biochar, such as poor adsorption capacity, narrow adsorption range, and other shortcomings, it is necessary to modify biochar to improve its applications in water treatment for ECs. Currently, there are a lot of reports on the removal of ECs from water by modified biochar. These studies explored different modification methods to functionalize biochar with various physicochemical properties, which resulted in distinct adsorption effects, behaviors and mechanisms of modified biochar on different ECs. There is a need to systematically review and digest the knowledge on the adsorption of ECs on modified biochar. In this review, recent biochar modification methods used in ECs removal are firstly summarized, and the adsorption performance and mechanisms of modified biochar on typical ECs are then systematically reviewed. Finally, the main research directions and trends, as well as recommendations and suggestions for future development are pointed out.
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Affiliation(s)
- Ning Cheng
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou, 550025, China
| | - Bing Wang
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou, 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou, 550025, China.
| | - Pan Wu
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou, 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou, 550025, China
| | - Xinqing Lee
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Ying Xing
- School of Chemistry and Materials Science, Guizhou Normal University, Guiyang, 550001, China
| | - Miao Chen
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou, 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou, 550025, China
| | - Bin Gao
- Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, 32611, USA
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