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Shi H, Chang G, Zhang Y, Zhao Y, Wang H, Zhang J, Zhu J. Biodegradation Characteristics and Mechanism of Aflatoxin B 1 by Bacillus amyloliquefaciens from Enzymatic and Multiomics Perspectives. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 38957116 DOI: 10.1021/acs.jafc.4c04055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Aflatoxin B1 (AFB1), a mycotoxin and natural carcinogen, commonly contaminates cereals and animal feeds, posing serious health risks to human and animal. In this study, Bacillus amyloliquefaciens ZG08 isolated from kimchi could effectively remove 80.93% of AFB1 within 72 h at 37 °C and pH 7.0. Metabolome and transcriptome analysis showed that metabolic processes including glycerophospholipid metabolism and amino acid metabolism were most affected in B. amyloliquefaciens ZG08 exposed to AFB1. The adaptation mechanism likely involved activation of the thioredoxin system to restore intracellular redox equilibrium. The key genes, tpx and gldA, overexpressed in Escherichia coli BL21, achieved degradation rates of 60.15% and 47.16% for 100 μg/kg AFB1 under optimal conditions of 37 °C and pH 8.0 and 45 °C and pH 7.0, respectively. The degradation products, identified as AFD1, were less cytotoxic than AFB1 in HepG2 cells. These findings suggest potential strategies for utilizing probiotics and engineered enzymes in AFB1 detoxification.
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Affiliation(s)
- Honghui Shi
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Guoli Chang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Yuhuan Zhang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Yan Zhao
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Haifeng Wang
- College of Animal Science, Zhejiang University, Hangzhou 310058, China
| | - Jinzhi Zhang
- College of Animal Science, Zhejiang University, Hangzhou 310058, China
| | - Junli Zhu
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
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Liu Y, Liu L, Huang Z, Guo Y, Tang Y, Wang Y, Ma Q, Zhao L. Combined Strategies for Improving Aflatoxin B 1 Degradation Ability and Yield of a Bacillus licheniformis CotA-Laccase. Int J Mol Sci 2024; 25:6455. [PMID: 38928160 PMCID: PMC11203865 DOI: 10.3390/ijms25126455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 06/05/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Aflatoxin B1 (AFB1) contamination is a serious threat to nutritional safety and public health. The CotA-laccase from Bacillus licheniformis ANSB821 previously reported by our laboratory showed great potential to degrade AFB1 without redox mediators. However, the use of this CotA-laccase to remove AFB1 in animal feed is limited because of its low catalytic efficiency and low expression level. In order to make better use of this excellent enzyme to effectively degrade AFB1, twelve mutants of CotA-laccase were constructed by site-directed mutagenesis. Among these mutants, E186A and E186R showed the best degradation ability of AFB1, with degradation ratios of 82.2% and 91.8% within 12 h, which were 1.6- and 1.8-times higher than those of the wild-type CotA-laccase, respectively. The catalytic efficiencies (kcat/Km) of E186A and E186R were found to be 1.8- and 3.2-times higher, respectively, than those of the wild-type CotA-laccase. Then the expression vectors pPICZαA-N-E186A and pPICZαA-N-E186R with an optimized signal peptide were constructed and transformed into Pichia pastoris GS115. The optimized signal peptide improved the secretory expressions of E186A and E186R in P. pastoris GS115. Collectively, the current study provided ideal candidate CotA-laccase mutants for AFB1 detoxification in food and animal feed and a feasible protocol, which was desperately needed for the industrial production of CotA-laccases.
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Affiliation(s)
- Yanrong Liu
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
| | - Limeng Liu
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
| | - Zhenqian Huang
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
| | - Yongpeng Guo
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China;
| | - Yu Tang
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
| | - Yanan Wang
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
| | - Qiugang Ma
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
| | - Lihong Zhao
- State Key Laboratory of Animal Nutrition and Feeding, Poultry Nutrition and Feed Technology Innovation Team, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.L.); (L.L.); (Z.H.); (Y.T.); (Y.W.); (Q.M.)
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Arimboor R. Metabolites and degradation pathways of microbial detoxification of aflatoxins: a review. Mycotoxin Res 2024; 40:71-83. [PMID: 38151634 DOI: 10.1007/s12550-023-00515-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/14/2023] [Indexed: 12/29/2023]
Abstract
The degradation of aflatoxins using nonpathogenic microbes and their enzymes is emerging as a safe and economical alternative to chemical and physical methods for the detoxification of aflatoxins in food and feeds. Many bacteria and fungi have been identified as aflatoxin degraders. This review is focused on the chemical identification of microbial degradation products and their degradation pathways. The microbial degradations of aflatoxins are initiated by oxidation, hydroxylation, reduction, or elimination reactions mostly catalyzed by various enzymes belonging to the classes of laccase, reductases, and peroxidases. The resulting products with lesser chemical stability further undergo various reactions to form low molecular weight products. Studies on the chemical and biological nature of degraded products of aflatoxins are necessary to ensure the safety of the decontamination process. This review indicated the need for an integrated approach including decontamination studies using culture media and food matrices, proper identification and toxicity profiling of degraded products of aflatoxins, and interactions of microbes and the degradation products with food matrices for developing practical and effective microbial detoxification process.
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Affiliation(s)
- Ranjith Arimboor
- Spices Board Quality Evaluation Laboratory, SIPCOT, Gummidipoondi, Chennai, 601201, India.
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