Mutagenesis And Strain-improving And The Fermentation Medium For Mutastrain Of Nicomycin Producing Strain The Marine Bacteria BAC-9912

The oceanic circumstance's characteristic is high pressure, high salt, low nourishmentand low temperature. It was considered the extreme circumstance of being. It was thecircumstance that maded the microbe category and metabolized path diversity. It canproduce novel biological activity substance that the terraneous microbe cannot produce. Themarine microbe would become the important resource of curatorial antibiotic andagricultural antibiotic. Bacterium strain BAC-9912 was separated from sea mud that canproduce the antifungal substance. It was determined as Bacillus licheniformis by classicalsystematic bacteriological identification and 16SrRNA molecular biological analysis.BAC-9912 can utilize the groovy culture medium and produce the antifungal substance. Itwas named Nincomycin. Nincomycin have extensive application foreground. Nincomycin producer, the marine bacteria BAC-9912 was mutagenesis withUV-irradiation and NTG. Chemic reagent and, by filteration two high yield strains 9912-72U(obtained from UV-irradiation treat) and 9912-2U-32N (obtained from NTG treat) wereobtained. The fermentation potency of two stains 9912-7-2U and 9912-2U-32N in shakerwere 17646.4iu/ml and 21780.8iu/ml, corresponding to the yield increased 126.9% and180.0% as compared with parent strain. Stability test demonstrated that the productivities oftwo mutant strains were stabled. Two models piece of agaragar largest throughput screen andcolony form screen were founded By Unifactor and 0bverse Meet Experiments, the fermentation medium for strain 9912-7-2u and 9912-2U-32N was optimized,which was as follow: 2.5% of glucose, 1.5% ofyeast extract, 0.04% of KH2PO4, 0.02% of FeSO4, 0.01% of ZnSO4, pH6.0 and pH 7.2.The 5ml seed culture (14h and 12h) was transferred into 250ml Erlenmeyer flask containing25ml of medium and incubated with rotary shaking for 26h at 28℃. The relative valence ofthe optimum fermentation liquid on Candida albicans achieved 21111.5u/ml and23195.6u/ml, which was increased by 23.2% and 27.6% compared with the original.