乳糖对产木聚糖酶基因工程菌1020的诱导作用及碳氮源优化

研究了国产及进口LB培养基对产嗜热性木聚糖酶基因工程菌1020生长及产酶的影响,并以国产原料为基准,优化了培养基。结果表明,国产的酵母膏及蛋白胨和进口原料相比,缺少某些成分,单纯增加用量不能弥补这种差别;乳糖可以代替昂贵的IPTG起到有效的诱导作用;10g·L-1的乳糖可兼起能源及诱导剂的双重效果,菌的生物量和产酶量达到最佳;发酵8h后补加5g·L-1乳糖,生物量及酶活皆有提高。复合氮源优于单一的无机或有机氮源。优化后的酶活从进口LB培养基的270U～290U提高到1700U～1800U。

Inductive Effects of Lactose on Xylanase of Recombinant Bacteria 1020 and the Optimization of Carbon and Nitrogen Source

The influence of LB culture from different company on biomass and xylanase activity of recombinant bacteria 1020, expressing thermostable xylanase was studied. Based on homemade material, the culture medium was optimized. The results showed that just because of the absence of some substance, the enzyme activity differed greatly from each other. Lactose could act as both carbon source and induction in place of expensive IPTG. The suitable concentration of lactose was 1.0%. And the biomass and xylanase activity could be further improved by adding 0.5% lactose in culture after cultivating for 8 hours. The complex nitrogen source was more suitable than single nitrogen source. Under the optimized medium, the enzyme activity was enhanced to 1700~1800U from 270~290U in LB medium.