嗜热脂肪芽孢杆菌产β-半乳糖苷酶发酵条件优化

Optimization of fermentation conditions for β-galactosidase produced by Bacillus stearothermophilus

研究了嗜热脂肪芽孢杆菌C953产β-半乳糖苷酶的发酵条件。研究得出C953产酶适宜培养基为:牛肉膏、大豆蛋白胨、NaCl、K2HPO4、KH2PO4;产酶的适宜发酵条件为:培养温度50℃,接种量10%,1000mL三角瓶的装液量200mL,初始pH7.0,摇床转速220r/min,培养时间24h。发酵液中β-半乳糖苷酶酶活力可达4.39NLU/mL。十二烷基磺酸钠-聚丙烯酰胺凝胶电泳法测定表明,β-半乳糖苷酶由分子质量为104.9kDa和114.3kDa的亚基组成。

Fermentation conditions of β-galactosidase produced by Bacillus stearothermophilus C953 were studied and presented.The study results showed that suitable culture compositions for β-galactosidase production were beef extract, soybean peptone, NaCL, K2 HPO4, KH2 PO4. The suitable fermentation conditions for β- galactosidase production were as follows：culture temperature was 50%, inoculation volume was 10%, liquid level was 200mL in 1000mL triangle bottle, original pH was 7.0, rotating speed was 220r/min and culture time was 24h. The final β-galactosidase activity in culture was about 4.39NLU/mL.The β-galactosidase produced by C953 was analyzed with SDS-PAGE,which showed that two subunits existed in β-galactosidase had molecular weight of 104.9kDa and 114.3kDa.