Enantioselective Catabolism of the Two Enantiomers of the Phenoxyalkanoic Acid Herbicide Dichlorprop by Sphingopyxis sp. DBS4

• Published in: Journal of agricultural and food chemistry 2020-07, Vol.68 (26), p.6967-6976
• Main Authors: Zhang, Long, Hang, Ping, Zhou, Xi-Yi, Qiao, Wen-Jing, Jiang, Jian-Dong
• Format: Article
• Language: English
• Subjects: 2,4-Dichlorophenoxyacetic Acid - analogs & derivatives; 2,4-Dichlorophenoxyacetic Acid - chemistry; 2,4-Dichlorophenoxyacetic Acid - metabolism; Agricultural and Environmental Chemistry; Biodegradation, Environmental; Herbicides - chemistry; Herbicides - metabolism; Sphingomonadaceae - metabolism; Stereoisomerism
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.0c01066

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.