The extent of cephalosporin C(CPC) production in producing strains is related with the expression or inhibition of the relevent genes. The goal of this study was manipulate of the producing strain in order to increase its CPC production. Acremonium chrysogenum DSM 2399 is used as parent strain. Mutagenesis is performed on solid form of optimized production media. UV ray and NTG (with their optimum doses) were used as mutagens. Random and directed (in presence of Hg++ or nystatin) selections were applied. Biological (Bioassay) and HPLC assays were performed for CPC measurment. The identity of CPC is confirmed by mass spectrometery in final resulting best strain. The optimum mutagenic doses of UV and NTG were 200 sec. And 5-7 min respectively. Also the inhibitory doses of Hg++ and Nystatin were 0.006g/dl and 0.3g/dl respectively. Raised titer mutants were obtained with both mutagens and both selection methods, although UV mutagen and the presence of Hg++ were more effective. CPC titer were rised 2.3 fold in final resulting mutant. CPC identity in its production media were shown by observing, the unique 415 ion in mass spectrometery. By mutagenesis protocols, it is available to chang the CPC-biosynthetic genes in producing strains and increase CPC titer.

Keywords: Key Words: 1) Strain improvement 2) Acremonium 3) Mutagenesis

Full-Text [PDF 214 kb]   (2704 Downloads)