The Research Of Key Enzymes And Plant Oil Mechanism During The Fermentation Of Cephalosporin C

Cephalosporin C is one of the β-lactam antibiotics produced by Acremoniumchrysogenum. Currently, glucose and plant oil were carbon source during thefermentation of cephalosporin C,but the low utilization rate of plant oil and the highprice restrict the development of cephalosporin C industry. In this paper the effect ofplant oil on cephalosporin C production, the influence of plant oil’s pretreatment and thekey enzyme of plant metabolic pathways were researched, to improve the efficiency ofutilization of plant oil production method of cephalosporin C.The fatty acid compositions of olive oil, peanut oil, soybean oil and blend oil wereanalysied by GC/MS. After comparing the fatty acid composition of four kinds of plantoil, we discovered that the linoleic acid content in the blend oil was significantly higherthan the others, and the content of oleic acid in olive oil was significantly higher thanthe other three kinds of oil. It means that the oleic acid can improve the level ofbiomass and linoleic acid can increase the production of cephalosporin C.The response surface analysis was carried out to optimize the enzymatic hydrolysiscondition of plant oil. With the optimal conditions of plant oil enzymatic hydrolysis, theenzymatic hydrolysis rate of plant oil was83.29%. When plant oil enzymatichydrolysed in the optimal conditions was used during the fermentation of cephalosporinC, the production of cephalosporin C increased by51%.After adding hydrogen peroxide in the fermentation medium, we analysed theactivity of α-oxoglutarate dehydrogenase complex and catalase, and the production ofcephalosporin C and α-aminoadipicacid are compared as well.The results showed thathydrogen peroxide reduced the activity of α-oxoglutarate dehydrogenase complexactivity significantly.At the same time, the activity of catalase was increased4.8times.The increase of the α-aminoadipicacid levels and cephalosporin C high-speed syntheticwere the same time. It means that the adding of hydrogen peroxide affect the alphaketone glutaric acid dehydrogenase and catalase in the directly or indirectly, and theproduction of cephalosporin C was improved finally. After sampling, extraction of totalRNA and QPCR, we analysed the expression of ogdh and pcbAB. The results showedthat hydrogen peroxide can reduce the expression of ogdh and induce the expression ofpcbAB.