摘要
目的通过对季也蒙毕赤酵母原生质体进行紫外诱变,筛选遗传性稳定的木糖醇高产菌株。方法制备季也蒙毕赤酵母DQ11的原生质体,计算原生质体生成率及再生率,并对制备过程中的酶浓度(0.5%、1.0%、1.5%和2.0%)、酶解温度(26、28、30、32和34℃)及酶解时间(1、2、3、4和5 h)进行优化。对采用最佳酶解条件制备的原生质体进行紫外诱变,分别检测诱变30、60、90、120和150 s时原生质体的致死率,经重复筛选,采用高效液相色谱法测定菌株发酵液的木糖醇含量,并检测筛选出的木糖醇高产菌株的遗传稳定性。结果最佳酶解条件为:酶浓度1.5%,酶解温度30℃,酶解时间3 h,该条件下制备的原生质体经紫外诱变90 s(最佳诱变时间)后,获得1株高产木糖醇诱变菌株YZ-57,其发酵液的木糖醇含量为9.78 g/L,比出发菌株DQ11提高了186%,且具有良好的遗传稳定性。结论季也蒙毕赤酵母原生质体经紫外诱变,成功获得一株季也蒙毕赤酵母木糖醇高产菌株YZ-57,且具有良好的遗传稳定性。
Objective To screen high xylitol-producing strains with genetic stability by ultraviolet mutagenesis of Pichia guilliermondii protoplast. Methods The protoplast of P. guilliermondii DQ11 was prepared, of which the generation and regeneration rates were calculated, and the enzyme concentration（0. 5%, 1. 0%, 1. 5% and 2. 0%）as well as temperature（26, 28, 30, 32 and 34 ℃）and time（1, 2, 3, 4 and 5 h）for zymolysis were optimized. The protoplast prepared under the optimal condition was subjected to ultraviolet mutagenesis, of which the death rates after mutagenesis for 30, 60, 90, 120 and 150 s were determined. The fermentation liquid of strain obtained by repeat screening was determined for xylitol content by HPLC, and the high xylitol-producing strain was evaluated for genetic stability. Results The optimal enzyme concentration, temperature and time for zymolysis were 1. 5%, 30 ℃ and 3 h respectively. A high xylitol-producing strain YZ-57 was obtained after ultraviolet mutagenesis of protoplast prepared under the optimal condition for 90 s, of which the xylitol content in fermentation liquid was 9. 78 g / L, increasing by 186% as compared with that of starting strain. Strain YZ-57 showed good genetic stability. Conclusion A high xylitol-producing strain YZ-57 was successfully obtained by ultraviolet mutagenesis of P. guilliermondii protoplast, which showed good genetic stability.
出处
《中国生物制品学杂志》
CAS
CSCD
2015年第8期861-865,共5页
Chinese Journal of Biologicals
基金
黑龙江省垦区科研项目(HNK11A-10-03)
关键词
紫外诱变
季也蒙毕赤酵母
原生质体
木糖醇
Ultraviolet mutagenesis
Pichia guilliermondii
Protoplast
Xylitol
