Breeding Of Baker's Yeast Of Rich Glutathione

In the paper,the effects of two different extract methods of glutathione from yeast were investigated and extraction conditions were optimized.The high GSH producing strain was constructed by complex mutagenesis and optimization of medium and fermentation conditions were studied.The results showed that Alloxan method is the suitable method in exterminating intraceller glutathione because of its good recurrence and veracity.Compared with two extraction methods,hot water extraction method is a valid method of extracting intraceller glutathione.Carries on the optimization to its extraction condition,the determination optimizes after the extraction condition is:the extraction temperature 90～95℃,extraction time 8min,extraction pH nature and extraction liquid volume 40mL.Biomass,glutathione yield and content of 15 strains of yeast were determined;Strain BY-14 was selected as original strain to be mutagenized.A Zinc Chloride-resistant mutant B-3 was obtained from its parent strain by UV treatment.The glutathione production of the mutant reached 78.23 mg/L by flask culture,which was 12%higher than the parent strain. And the glutathione content in the dried cells reached 14.82mg/g,which was 11%higher than the parent strain.The optimal fermentation medium is gained by uniform experiment design.Based the above conditions,the batch flask-shaking is performed with B-3 mutation.The yield of glutathione has reached 96.72mg/L in the optimal process,which was 23.63%higher than that of non-optimized medium,and the glutathione content reached 18.96mg/g,which was 28%higher than that of non-optimized medium.To obtain high-yield glutathione strain,low energy N~+ ion implantation technology and screening of L-Ethionine-resistant.Mutants are used in the study on breeding mutation. A Ethionine-resistant mutant BL-23 was obtained with glutathione yield have been greatly increased,its glutathione yield has increased by 17.3%,can reach 113.46mg/L,the glutathione content reached 20.86mg/g,which was 10%higher than the parent strain.