VC二步发酵产酸菌氧化葡萄糖酸杆菌的选育

Screening of Associated Bacteria Gluconobacter Oxydans in Two-step Fermentation of VC

实验通过紫外线两轮诱变的方法诱变选育氧化葡萄糖酸杆菌(Gluconobacteroxydans),以实现提高2-酮基-L-古龙酸(2-KLG)产量的目的,获得1株高产2-KLG的菌株G5。结果证明该突变菌株在pH6.5-6.7的发酵培养基中与蜡质芽孢杆菌(Bcilluscereus)混合发酵,G5的平均糖酸转化率提高了13.49%,酸量达到83.6mgmL,发酵周期缩短了2-3h。经连续10代转接发酵实验,证明其产酸稳定性较好。结论:氧化葡萄糖酸杆菌(Gluconobacteroxydans)的突变体G5提高了糖酸转化率,缩短了发酵周期。

Gluconobacter oxydans was converted into G5 which produces high 2- KLG by UV mutation with ultraviolet light for two times continuously. The result indicated the convertion ratio of L- sorbose to 2 - KLG was increased 13.49% and 2 - KLG added up to 83.6mg/mL in the medium of pH 6.5 - 6.7 when they were cultured with Bacillus cereus. The fermentation time of mutant strain G5 was 2 - 3 hours in advance than CK. The characteristics of G5 was shown stable after continuously transferred for 10 generations. Conclusion： Gluconobacter oxydans mutant increased the convertion ratio of L-sorbose,furthermore the fermentation time was shorter than before.