Different degradation patterns and mechanisms of chiral contaminant enantiomers: beta-cypermethrin as a case study.

ABSTRACT

Studies often neglect the differences between enantiomers in soil chiral contaminants, and the molecular ecological mechanisms involved in enantiomer selective degradation behaviors remain elusive. In the present study, we used the stepwise regression analysis to establish the quantitative relationships between degradation rates and genes that determine different degradation patterns and mechanisms among enantiomers; and beta-cypermethrin (BCYM) was chosen as the target analyte. Stepwise regression analysis demonstrated the relationships established for different enantiomers varied even under the same conditions, and results from path analysis showed the same functional gene exhibited different direct and indirect contributions to different enantiomer degradation rates. The genome and primary microbial communities during different enantiomer degradation rates were also analyzed based on Illumina MiSeq next-generation sequencing technology, and the results indicated the soil microbial community structure and abundance varied during different enantiomer degradation rates. Results from this study served to enhance our understanding of the molecular biological mechanisms of chiral contaminant selective degradation behaviors under the context of functional genes and degrading microorganisms.