Production of Killer Toxin from a Mutant of Hansenular capsulata S-13

Hansenular capsulata S-13의 변이주에 의한 Killer Toxin의생산

Killer yeast, Hansenular capsulata S-13 were treated with heat, ethylmethane sulfonate and N-methyl-n'-nitro-n-nitrosoguanidine and a mutant(S13-E1), showing 2-fold higher killer toxin activity than that of parent strain to killer sensitive strain, Saccharomyces cerevisiae ATCC 38026 was obtained. Hansenular capsulata S13-E1 showed strong killer toxin activity to Saccharmyces mellis and Saccharomyces sal년 and four strains of gas-producing yeasts from traditional Doenjang and Kochujang. The culture condition for killer toxin production by Hansenular capsulata S13-E1 was optimized to be 1.0% potato extract, each 0.5% of peptone and glucose, and 0.025% MgSO4 with initial pH 4.5 at 3$0^{\circ}C$ and 36 hr of batch cultivation.