瘤胃源粪臭素降解菌的分离鉴定及其降解特性研究OA北大核心CSTPCD

[Objective]The aim of this study is to isolate skatole-degrading bacteria from the rumen of sheep and estimate its skatole-degrading ability and growth performance,to develop suitable direct-fed microbials for ruminants to reduce odor.[Method]The MSM medium containing skatole was used for enrichment and isolation from the rumen fluid of sheep.The bacterial colony morphology was used for primary classification.Amplification,sequencing and phylogenetic analysis of 16S rRNA gene were carried out for further identification.The growth curve was drawn,and degradation curve of skatole was determined using HPLC.[Result]A total of 25 skatole-degrading strains were obtained,and 11 representative strains(MSML1-11)of them were selected based on colony morphology for further study.MSML2 and MSML6 belonged to Bacillus subtilis,MSML4,MSML5,MSML7 and MSML10 belonged to Priestia aryabhattai,MSML3 and MSML11 belonged to Burkholderia contaminans.MSML1,MSML8 and MSML9 belonged to Pseudomonas chengduensis.Among these strains,MSML5 grew at the fastest rate.Its stable phase appeared after 12 h,and the bacterial concentration in the stable phase was the highest.MSML3 and MSML8 grew slowly in the first 16 h and reached a stable phase after about 32 h.In terms of skatole degradation,MSML2 showed the highest skatole degradation efficiency of 23.03%within 48 h,followed by MSML7,MSML8 and MSML10,with a degradation rate higher than 20%.[Conclusion]This research successfully isolated skatole-degrading bacteria from the rumen of sheep,including four different species.Bacillus subtilis,Priestia aryabhattai and Pseudomonas chengduensis with skatole-degrading ability are reported for the first time,which provides valuable resources for the development of microbial agents directly fed to ruminants.