The Analysis Of Proteomic And Strain Development Of Clostridium Acetobutylicum ATCC 55025

Due to globle energy shortage and the impact of energy combustion on the environment,the research of bio-butanol has attracted increasing attention all over the world.Clostridium acetobutylicum,an important strain for the production of bio-butanol,have more and more studies for the metabolic pathway in recent years.Clostridium acetobutylicum ATCC 55025 is a chemical mutation strain of Clostridium acetobutylicum ATCC 824.The yield of butanol in ATCC 55025 could reached 12 g/L.In this study,the proteomics of Clostridium acetobutylicum ATCC 55025 in acidogenesis and solventogenesis were analyzed to find the differentially expressed proteins and phosphoproteins.Genes encoding serine/threonine kinases in Clostridium acetobutylicum ATCC 55025 were respectively knocked out and overexpressed,respectively,and genes encoding cell division proteins were knocked out in this study.The ABE fermentation of modified strains were accomplished to evaluate the fermentation performance and morphological change.A total of 801 proteins were identified by proteomic analysis in Clostridium acetobutylicum ATCC 55025.Among them,26 proteins were significantly up-regulated in solventogenesis and 17 proteins were significantly down-regulated in solventogenesis.A total of 27 phosphorylation sites in 22 proteins were successfully identified by Ti⁴⁺-IMAC phosphopeptide enrichment,among which three threonine sites of serine/threonine kinase Cac1728 were phosphorylated.The genes encoding serine/threonine kinases Cac0404,Cac0579,Cac1728,Cac2400,and cell division proteins Cac1251,Cac2118,Cac2125 were knocked-out by group-II intron gene inactivation technology.The genes encoding serine/threonine kinases Cac0404,Cac0579,Cac1728 and Cac2400 were overexpressed by the gene overexpression technology.The results showed that the knockout of cac2400 gene played significant roles in cell growth and solvent production,the knockout of cac1728 gene increased the glucose consumption and butanol production,but the cell growth was inhibited.The knockout of cac2118 gene affected the cell morphology and size,which was showed a spherical-shape,the knockout of cac2125 and cac1251 genes inhibited the cell growth,and then affected the solvent formation.The overexpression of four serine/threonine kinases inhibited cell growth,glucose utilization and solvent formation.In this study,the proteomic of Clostridium acetobutylicum ATCC 55025 was further analyzed,and the regulation of serine/threonine kinases and cell division proteins in the ABE fermentation process was comprehensively studied.The results provide a significant basis for the study of serine/threonine kinases and cell division proteins of Clostridium acetobutylicum.