硒浓度梯度驯化结合紫外诱变法选育富硒酵母菌研究

Selenium concentration gradient domestication combined with ultraviolet mutation breeding of Se-enriched yeast

为获得高产富硒酵母,通过硒浓度梯度驯化啤酒酵母Sac.cerevisiae Fec205、戴氏酵母Sac.delbrueckii Fec209、热带假丝酵母Candida tropicalis Fec2011等3株酵母菌,结果显示啤酒酵母Sac.cerevisiae Fec205比其他2株酵母的耐硒性能更强。因此以啤酒酵母Sac.cerevisiae Fec205为原始菌株进行紫外诱变以提高其富硒能力。通过硒抗性筛选,挑取出6株生长快、菌落大的突变菌株单菌落。取发酵培养基中生物量大的3株酵母菌Sac.cerevisiae Y-3,Y-4,Y-1,接种于硒浓度为40μg/ml发酵培养基,结果显示选育出的3株诱变后的啤酒酵母Sac.cerevisiae Y-3,Y-4,Y-1的硒含量分别为932、832、915μg/g,其中最高的Y-3比原始菌株啤酒酵母Sac.cerevisiae Fec205的硒含量增长50.08%、生物量提高了50.97%。

In order to obtain the high yield selenium-enriched yeast,Sac.cerevisiae Fec205,Sac.delbrueckii Fec209 andCandida tropicalisFec2011were chosen as starters.After selenium concentration gradient domestication,Sac.cerevisiae Fec205 had shown the better selenium endurance ability than the other two strains,and was chosen to improve the selenium content as the original strain,combined with ultraviolet mutation.Six mutant macrocolony were picked out through screening test of selenium endurance.Three yeast strains,which had high biomass in fermentation medium of 40μg/ml of selenium,were named Y-3,Y-4,Y-1.Results showed that：the content of selenium of three mutant strains Y-3,Y-4,Y-1were increased to 932,832,915μg/g,respectively.The content of selenium and biomass of mutant strains Y-3increased by 50.08% and 50.97%,respectively,compared with the original strain Sac.cerevisiae Fec205.