一株瘤胃中降解玉米赤霉烯酮假单胞菌的分离鉴定及降解特性研究OA

This experiment aimed to screen for microorganisms capable of efficiently degrading zearalenone(ZEN)from bovine rumen fluid.Bacteria were isolated from bovine rumen fluid using MS liq-uid medium with ZEN as the sole carbon source,and the strains were identified through microbiological and molecular biological methods.Enzyme-linked immunosorbent assay was employed to evaluate the effects of different reaction times,temperatures and other factors on the ZEN-degrading activity of the strains.The potential mechanism of action was preliminarily explored by measuring the ZEN-degrading ca-pacity of different bacterial fractions.A bacterial strain with a ZEN degradation rate of 58.29％was ob-tainned.Microscopic examination revealed it to be Gram-negative,rod-shaped or slightly curved.16S rRNA gene sequence BLAST analysis showed that the strain had the highest homology with Pseudomonas sp.VR09P2.The results of the strain's ZEN degradation rate under different culture conditions indicated that:(1)The degradation rate increased with prolonged reaction time.(2)ZEN could be degraded across a tem-perature range of 10～42℃,with the highest degradation rate observed at 37℃.(3)The degradation rate increased with higher initial bacterial concentrations,reaching its peak(68.42％)at 109 CFU/mL.(4)The degradation rate gradually decreased as pH increased.The ZEN degradation rates of inactivated bacteria,cell-free supernatant,intracellular contents,and cell wall suspension were 0％,0.03％,65.16％,and 24.12％,respectively.In this study,a Pseudomonas strain with ZEN-degrading activity was isolated,which could serve as a candidate strain for the biodegradation of ZEN.Its degradation of ZEN is likely primarily attributed to the action of intracellular enzymes.