摘要
从内蒙古锡林郭勒酸马奶中分离筛选出一株酵母菌A9,通过A9的紫外(UV)诱变、硫酸二乙酯(DES)单因素实验,确定最佳诱变参数。结果表明,最佳紫外诱变参数为于30 W紫外灯下、距灯30 cm处、紫外照射75 s时,紫外诱变的致死率为78.9%;最佳的硫酸二乙酯诱变参数为将加入1%DES的菌悬液、在35℃的水浴恒温振荡箱中、振荡15 min,硫酸二乙酯诱变的致死率为76.1%。经过3轮连续复合诱变,筛选出4株突变菌株,与出发菌株A9共同进行耐高渗(高糖)实验,当耐高渗(高糖)培养基中的葡萄糖浓度为65%时,出发菌株A9的生长完全被抑制,而突变菌株A9-2在此条件下依旧生长,A9-2的耐高渗(高糖)性能明显高于A9,最终筛选出A9-2为最佳耐高渗(高糖)菌株。通过酒精发酵实验,突变菌株A9-2的10代发酵液,其CO2的总失重量为13.20 g,残糖量为13.9°Bé,酒精度5.1%(v/v),与3代发酵液各项指标相似,确定遗传性能稳定,且菌株发酵力、酒精度明显高于出发菌株A9。
A strain of yeast A9 was screened out from koumiss in Xinlingol, Inner Mongolia.The best conditions for mutagen of A9 were investigated by UV and single-factor test of DES.The results showed that, by UV screening experiment, the optimal parameters of UV was confirmed.Under the 30 W UV lamp,distance from UV lamp 30 cm, shining 75 s, the fztality rate of UV mutation was 78.9% .The optimal parameters were DES of 1% and shocked conditions of water-bath shocking box at the 35 ℃ for 15 min, and fatality rate of DES mutation was 76.1%.After three times continuous UV-DES compound mutations,4 mutant stains were selected to screen of high sugar-tolerant with A9.When the glucose concentration was 65% in the high-sugar- tolerant medium, the growth of A9 was suppressed but the A9-2 still grown under the same conditions.The high-sugar-tolerant performance of A9-2 was better than A9, so the best high-sugar-tolerant strain was A9-2.By the experiment of alcoholic fermentation,the weight loss of CO2, residual sugar, and alcoholic strength of the tenth fermentation of A9-2 were 13.20 g, 13.9° B6 and 5.1% （v/v） , which was similar to the third fermentation and its heredity performance was stable.The fermentation performance of A9-2 was higher than that of the original strain A9 obviously.
出处
《食品工业科技》
CAS
CSCD
北大核心
2017年第15期50-54,共5页
Science and Technology of Food Industry
基金
内蒙古自治区自然科学基金(2014MS0359)
