JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
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IF 6.7
Boxiang Kou,Zexun Wang,Yujia Wang,Meng Shen,Zhaoyi Zheng,Yecheng Gao,Dan Ma,Sijun Dong
Cephalosporin residues in agricultural soils, food systems, and aquatic environments pose severe threats to food safety, public health, and the ecological environment. While biodegradation represents a promising remediation strategy, the degradation mechanisms for most cephalosporins remain elusive. In this study, Pseudochrobactrum asaccharolyticum TY12 was isolated and demonstrated a broad-spectrum ability to degrade multiple cephalosporins. Notably, strain TY12 exhibited the highest cefixime (CFX) degradation efficiency, achieving a 93.87% removal of 100 mg/L CFX within 12 h. Ten degradation products of CFX were identified via high-resolution mass spectrometry, leading to a proposed degradation pathway. Notably, these products exhibited significantly attenuated antibacterial activity. Transcriptomic analysis and heterologous expression identified β-lactamase TY3865 as the key enzyme. Furthermore, molecular docking and site-directed mutagenesis revealed the residues critical for its catalytic activity. These findings provide mechanistic insights into antibiotic biodegradation and demonstrate the potential of TY12 for treating cephalosporin-contaminated wastewater.
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PubMed
高影响因子
PROCESS BIOCHEMISTRY
·
2018
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IF 2.616
Feng Cheng,Feifei Cheng,Jianyong Zheng,Guanzhong Wu,Yinjun Zhang,Zhao Wang
Only a few esterases have been used for the synthesis of optically pure fungicide. For example, ( R )-metalaxyl synthesized using esterase-involved bioreaction displays fungicide activity, whereas ( S )-enantiomer is redundant. However, the biosynthesis of ( R )-metalaxyl is currently hampered by the lower activity, selectivity and thermostability of esterase. Therefore, to obtain a better biocatalyst, several esterase genes were cloned from Pseudochrobactrum asaccharolyticum WZZ003. The esterase PAE07, among eight enzymes, was selected because it exhibited the highest hydrolysis activity toward ( R , S )-DMPM. The DNA and amino acid sequence analysis suggested that PAE07 is a new member of lipolytic enzyme family V. The enzymatic properties of PAE07 toward ( R , S )-DMPM and model substrate ( p- nitrophenyl acetate) were investigated. PAE07 was found to be a highly active esterase with excellent enantioselectivity . The reaction conditions including temperatureand pH were optimized, and the effects of metal ions, organic solvents and detergents were also investigated. Results indicated that PAE07 is a competitive candidate for ( R )-metalaxyl manufacturing.
研究领域:
生物化学
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酶工程
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农药合成
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DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
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2022
·Vol. 46
·期 2
·171-181
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IF 3.434
Zhang Yin-Jun,Wei Li-Tian,Zhou Ming-Peng,Wei Chun,Yu Xin-Jun
( R )-N-(2,6-dimethylphenyl) aminopropionic acid methyl ester (( R )-DMPM) is an important chiral intermediate of the fungicide N-(2,6-Dimethylphenyl)-N-(methoxyacetyl)-alanine methyl ester (( R )-Metalaxyl). In this study, (1) D3520 (macroporous acrylic anion resin), selected from the ten resins, was used to immobilize the esterase from Pseudochrobactrum asaccharolyticum WZZ003 (PAE07) for resoluting the ( R,S )-DMPM to obtain ( R )-DMPM. (2) Up to 20 g/L PAE07 could be immobilized onto D3520 with a high enzymatic activity of 32.4 U/g. Moreover, the Km and Vmax values of 19.1 mM and 2.8 mM/min for D3520-immobilized PAE07 indicated its high activity and stereoselectivity. (3) The optimal temperature and pH for the immobilized PAE07 were 40 ℃ and 8.0, and substrate concentration was up to 0.35 M. After 15 h reaction, the conversion rate from ( R,S )-DMPM to ( R )-DMPM was 48.0% and the e.e.p and E values were 99.5% and 1393.0, respectively. In scale-up resolution, 200 g/L substrate and 12.5 g immobilized esterase PAE07 condition, a conversion rate from substrate to product of 48.1% and a product e.e.p of 98% were obtained within 12 h, with the activity of immobilized PAE07 retained 80.2% after 5 cycles of reactions. These results indicated that the D3520-immobilized esterase PAE07 had great potential for enzymatic resolution of ( R,S )-DMPM to prepare ( R )-Metalaxyl.
研究领域:
生物化学
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酶工程
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有机合成
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DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
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2022
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IF 8.431
Kaixiong Yang,Wenwen Wang,Lin Li
Dichloromethane (DCM) is a recalcitrant volatile organic compound that exhibits biological toxicity and bioaccumulation. In this study, gaseous DCM was removed using an electroactive bacterial biofilter (EBB) with graphite rod as the anode and carbon felt as the cathode. The highest removal efficiency (97.09%) was achieved at a cathodic potential of −600 mV (vs. Ag/AgCl). The EBB had a maximum elimination capacity of 79.29 g m −3 h −1 when the inlet load was 96.48 g m −3 h −1 . There was no substrate inhibition phenomenon observed in the EBB, and the Michaelis–Menten model was used to describe the kinetics of the EBB. High-throughput sequencing indicated that electroactive genera such as Rhodanobacter sp., Sphingomonas sp., Pseudomonas sp., Chryseobacterium sp . , Pseudochrobactrum sp., and Mycobacterium sp. dominated the EBB. The microbial communities were stable and were slightly affected by the DCM inlet concentration. The results can be applied for the effective treatment of recalcitrant volatile organic compounds (VOCs).
研究领域:
环境工程
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生物技术
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微生物学
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DOI
PubMed
高影响因子
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