Dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propanoic acid; DCPP], an important phenoxyalkanoic acid herbicide (PAAH), is extensively used in the form of racemic mixtures (Rac-DCPP), and the environmental fates of both DCPP enantiomers [(R)-DCPP and (S)-DCPP] mediated by microorganisms are of great concern. In this study, a bacterial strain Sphingopyxis sp. DBS4 was isolated from contaminated soil and was capable of utilizing both (R)-DCPP and (S)-DCPP as the sole carbon source for growth. Strain DBS4 preferentially catabolized (S)-DCPP as compared to (R)-DCPP. The optimal conditions for Rac-DCPP degradation by strain DBS4 were 30 °C and pH 7.0. In addition to Rac-DCPP, other PAAHs such as (RS)-2-(4-chloro-2-methylphenoxy)propanoic acid, 2,4-dichlorophenoxyacetic acid, 4-chloro-2-methylphenoxyacetic acid, and 2,4-dichlorophenoxyacetic acid butyl ester could also be catabolized by strain DBS4. Bioremediation of Rac-DCPP-contaminated soil by inoculation of strain DBS4 exhibited an effective removal of both (R)-DCPP and (S)-DCPP from the soil. Due to its broad substrate spectrum, strain DBS4 showed great potential in the bioremediation of PAAH-contaminated sites.

中文翻译：

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Sphingopyxis sp。的苯氧基链烷酸除草剂双氯丙酸酯的两个对映体的对映选择性分解。DBS4。

二氯丙[（RS）-2-（2,4-二氯苯氧基）丙酸; DCPP]，一种重要的苯氧基链烷酸除草剂（PAAH），以外消旋混合物（Rac -DCPP）的形式广泛使用，并且两种DCPP对映异构体[（R）-DCPP和（S）-DCPP]的环境命运均由微生物是非常令人关注的。在这项研究中，一种细菌菌株Sphingopyxis sp.。DBS4是从受污染的土壤中分离出来的，能够将（R）-DCPP和（S）-DCPP用作唯一的生长碳源。与（R）-DCPP相比，菌株DBS4优先分解代谢（S）-DCPP。Rac的最佳条件DBS4菌株的-DCPP降解温度为30°C，pH为7.0。除Rac -DCPP外，其他PAAH也有（RS）-2-（4-氯-2-甲基苯氧基）丙酸，2,4-二氯苯氧基乙酸，4-氯-2-甲基苯氧基乙酸和2,4- DBS4菌株也可以分解二氯苯氧基乙酸丁酯。通过接种菌株DBS4对Rac -DCPP污染的土壤进行生物修复，可有效去除土壤中的（R）-DCPP和（S）-DCPP。由于其底物范围广，菌株DBS4在PAAH污染位点的生物修复中显示出巨大潜力。