富硒酵母的诱变及突变株的筛选研究  

Mutation of Selenium-rich Yeast and Isolation of Mutants

作　　者：贺莹[1] 赵建英[1] 高平[1] 杨晓娟[1] 

机构地区：[1]吕梁学院生命科学系,吕梁033000

出　　处：《食品工业》2017年第2期204-207,共4页The Food Industry

基　　金：吕梁学院科研基金项目资助(ZRQN201403);吕梁学院大学生创新创业项目(CXCYZD201503);山西省大学生创新创业项目(2015456)

摘　　要：以实验室冷藏的从馒头酵子中提取的馒头酵母作为出发菌株,把有机硒的含量作为筛选的指标,在诱变过程中,采用紫外线进行物理诱变和硫酸二乙酯(DES)进行化学诱变,诱变的菌种用10倍梯度稀释法稀释至10-5,取10-3,10-4和10-5涂平板,每个梯度涂3个平板,记录平板上的菌落数,并计算致死率。选用物理诱变和化学诱变的最佳致死率作为复合诱变的试验条件。通过初筛,从而选出较强的菌株12株,编号为Y1~Y12,接下来测定烘干的酵母生物量以及有机硒的含量,选育出一株生物量和富硒能力都最高的菌株Y9,该菌株的生物量为12.91 g/L,硒的含量为879μg/g,此菌株硒的含量比原始菌株提高了1.5倍,生物量比原来提高了39%。对Y9菌株连续传代三次,原菌株与三次传代菌株一起发酵培养,用吸光光度法测定有机硒的含量,通过吸光度的比较,得出硒的含量分别为875,869,870和872μg/g,硒的含量没有明显的变化,说明菌株没有发生回复突变,具有一定的稳定性。The bread yeast extracted from laboratory frozen bread yeast as original sWam, the content of organic selenium as a screening indicator in the mutagenesis process, using ultraviolet physical mutagenesis and diethyl sulfate （DES） chemical mutagenesis, mutagenesis strains diluted 10 fold dilution method to 10^-5, taking 10^-3, 10^-4 and 10^-5 coated tablet, each gradient coating the plate, record the bacterium number, and calculate the death rate. Select the best physical death rate of mutagenesis and chemical mutagenesis as a composite mutagenesis test condition. By screening, 12 strong strains were selected, and numbered from Y1 to Y12, followed by determination of the biomass dried yeast and organic selenium. The strain Y9 with high biomass and Se capabilities was selected and bred, and the biomass and the selenium content of the sWain were 12.91 g/L and 879 μg/g. The selenium content of this strain increased 1.5 times than that of the original sWain, and biomass of this strainincreased 39% than that of the original swain. Upon serially passaging three times, ferment the original strains and three passages strain together, spectrophotometric used to determine the organic selenium content. By comparing the absorbance values, obtain selenium contents were 875, 869, 870 and 872 μg/g. The selenium content did not change significantly, indicating that the strain did not happen back mutations, so it had certain stability.

关 键 词：富硒酵母 诱变 抗性筛选 硒的测定 

分 类 号：TS201.3[轻工技术与工程—食品科学]