[Screening of trans-3-methyl-2-hexenoic acid-degrading bacteria and analysis of their degradation pathways].

Trans-3-methyl-2-hexenoic acid (E3M2H) is a widely recognized as one of the key components leading to bromhidrosis. At present, the screening of E3M2H-degrading strains and the research on the molecular mechanism underpinning the efficient microbial degradation of E3M2H remain to be carried out. In this study, Rhodococcus qingshengii SDb-8 with high E3M2H degradation efficiency was isolated from forest soil and bath wastewater samples. Furthermore, the differential metabolic pathways of E3M2H and its structural analogues in the strain were analyzed by non-targeted metabolomics. R. qingshengii SDb-8 was found to raise the levels of substances such as 2,2-dimethylvaleric acid and 4-methylhexanoic acid during the oxidation of E3M2H by this strain. Furthermore, the expression levels of genes encoding diaminobutyric-2-oxoglutarate transaminase, L-2,4-diaminobutyric acid acetyltransferase, and L-carnosine synthase were significantly upregulated. This study not only provides a new microbial resource for the biodegradation of E3M2H but also lays an experimental foundation for elucidating the microbial degradation mechanism of E3M2H and provides a theoretical basis for developing a new strategy for the treatment of bromhidrosis based on microbial degradation.