The Effect Of Cyclodextrin On The Characteris Of Mycobacteria Biotransformation Based On Proteomics And Metabolomics

Mycobacterium neoaurum M3AksdD ksdD-MNR(HB)performed the production of androst-1,4-diene-3,17-dione(ADD)and 4-ene-3,17-dione(AD)from phytosterol(PS).Cyclodextrin(CD)was usually added into transformation system as a cosolvent,in addition to the physical solubilization,it also affects the cell membrane permeability and substrate/product transfer process,further to increase the conversion of substrate.In this study,the changes of cell characteristics of CD-treated HB at different time were studied,including growth,types and relative contents of intracellular metabolites and the changes of proteome at 60h.Besides,the effect of CD on the characteristics of HB were studied during transformation.The results has important scientific significance for the characteristics of CD application in microbial metabolic and the understanding of the relationship between cyclodextrins with physical basis.The differences of intracellular metabolites at different time of CD-treated HB were analyzed by GC-MS and statistical analysis.The results showed that there were significant changes in metabolites at 24 h and 60 h,but there was no significant difference at 48 h.The main biomarkers were sugars,amino acids and fatty acids.The relative content of carbohydrate decreased,amino acids increased,fatty acids increased,and polyunsaturated fatty acids decreased.The differential proteins were analyzed by relative quantitative iTRAQ technique and bioinformatics analysis.The results showed that 41 of the differential 81 proteins were up-regulated and 40 were down-regulated.The molecular functions of the differential proteins were ribosomes,rRNA-binding proteins,translation and hydrolase activities.The up-regulated proteins were mainly functioned in the cell membrane transport system,Nucleic acid repair system and redox process,while the down-regulated proteins were mainly involved in the cellular nucleic acid metabolic pathway.The results showed that the type and relative content of intracellular metabolites of HB,which was transformating PS into AD/ADD in CD system,were significantly different(P<0.05)from that of in CD system at 60 h.The relative content of intracellular carbohydrate decreased,amino acids and saturated fatty acid increased.107 of 145 different proteins were up-regulated,38 were down-regulated.The up-regulated proteins were mainly involved in lipid metabolism and oxidative phosphorylation.The increase of key enzymes quantity in the process of the degradation of PS,such as,dehydrogenase,cholesterol single oxygenase and 3-sterone-1-dehydrogenase expression,which suggests that cyclodextrin might promote the degradation process.