Biotransformation of doxycycline by Brevundimonas naejangsanensis and Sphingobacterium mizutaii strains
Biotransformation of doxycycline by Brevundimonas naejangsanensis and Sphingobacterium mizutaii strains
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DOI：
10.1016/j.jhazmat.2021.125126
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发表时间：
2021-01-22
影响因子：
13.6
通讯作者：
Li, Xu
中科院分区：
文献类型：
--
作者：
He, Ting;Bao, Jianguo;Li, Xu
多西环素（DC）是第二代四环素类抗生素，由于其广泛的应用，近年来其在环境中的去向越来越受到人们的关注。关于DC在环境中的生物降解性知之甚少。本研究的目的是表征DC的生物转化纯菌株在不同的环境条件下的反应动力学和生物转化产物。从鸡粪中分离到两株细菌，分别为Brevundimonas naejangsanensis DD 1和Sphingobacterium mizutaii DD 2，并对其转化DC的能力进行了研究。结果表明，两种菌株都依赖于彗星生物转化DC与胰蛋白胨作为主要生长底物。DD2具有比DD1更高的生物转化动力学。这两种菌株偏好相似的pH值（7和8）和温度（30 ℃），然而，它们对增加背景胰蛋白胨浓度表现出相反的反应。在水解转化DC为其异构体或差向异构体的同时，两种细菌菌株通过一系列脱甲基、脱水、脱羰基和脱氨基将DC转化为各种生物转化产物。这项研究的结果可以用来更好地预测DC在环境中的命运。
The fate of doxycycline (DC), a second generation tetracycline antibiotic, in the environment has drawn increasing attention in recent years due to its wide usage. Little is known about the biodegradability of DC in the environment. The objective of this study was to characterize the biotransformation of DC by pure bacterial strains with respect to reaction kinetics under different environmental conditions and biotransformation products. Two bacterial strains, Brevundimonas naejangsanensis DD1 and Sphingobacterium mizutaii DD2, were isolated from chicken litter and characterized for their biotransformation capability of DC. Results show both strains rely on cometabolism to biotransform DC with tryptone as primary growth substrate. DD2 had higher biotransformation kinetics than DD1. The two strains prefer similar pHs (7 and 8) and temperature (30 degrees C), however, they exhibited opposite responses to increasing background tryptone concentration. While hydrolysis converted DC to its isomer or epimer, the two bacterial strains converted DC to various biotransformation products through a series of demethylation, dehydration, decarbonylation and deamination. Findings from the study can be used to better predict the fate of DC in the environment.