摘要
将来源于Clostridium cellulolyticum H10的DPEase基因在食品级表达系统Bacillus subtilis中进行产酶研究,在3L发酵罐中高密度发酵最终酶活可达495U/ml,得到高表达量的DPEase酶液。通过硅藻土-海藻酸钠（吸附包埋法）对重组细胞进行固定化研究,结果表明,当海藻酸钠浓度为2%、细胞包埋量为50g/L、CaCl_2浓度为2%、硅藻土浓度为1%时,固定化细胞酶活回收率可达64%,固定化细胞与游离细胞相比最适pH不变,最适温度提高5℃,热稳定性明显提高,连续反应7个批次后转化率仍然为28%,仍保持81%的残余酶活,具有很高的工业应用价值。
The DPEase gene from Clostridium cellulolyticum H10 was studied on the enzyme production in the food grade expression system Bacillus subtilis. The final enzyme activity was 495 U/ml by high-cell-density fermentation in the 3 L fermentor. The recombinant cells were immobilized by diatomite-sodium alginate（ adsorption-occlusion method）; the optimized immobilized conditions were as follows： 2% sodium alginate,50 g/L cell concentration,2% CaCl_2 and 1% diatomite. Under the optimum condition,the recovery rate reached64%. Compared with the free cells,the immobilized cells had the same optimal pH,the optimal temperature was increased by 5℃; and the thermal stability was significantly improved. The conversion rate was still 28% after 7 times repeated operations; it was also maintained 81% of the residual enzyme activity,which had a high industrial application value.
作者
孙帆
宿玲恰
张康
吴敬
SUN Fan;SU Ling-qia;ZHANG Kang;WU jing(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education,Jiangnan University,Wuxi 214122,China;International Joint Laboratory on Food Safety,Jiangnan University,Wuxi 214122,China)
出处
《中国生物工程杂志》
CAS
CSCD
北大核心
2018年第7期83-88,共6页
China Biotechnology
基金
国家自然科学基金(31501419)
国家杰出青年基金(31425020)资助项目
