A Secreted Expression Vector Construction of β-Glucosidase Gene and Its Expression in Picchia pastoris
About 2500 bp gene without signal peptide from Aspergillus niger encoding sequence bgl1 was connected to the Pichia pastoris expression vector pPICZ α-A, resulting in the recombinant expression plasimid pPICZα-A-bgl1. It was transformed into P. pastoris GS115 competent cells after Pme I digestion. With the induction of methanol, bgl1 gene in P. pastoris has got a higher level secretory expression. Shake flask experiments showed that there was a corresponding increase in extracellular protein secretion in fermentation broth as the methanol induction time increased. After 8d induced fermentation, the content of extracellular protein reached 1.36 mg /ml and the β-glucosidase activity was up to 7.75IU/ml which was 2.8 times compared to original strain. The relative molecular weight of recombinant β-glucosidase was about 125kD by SDS-PAGE analysis. The optimal enzyme reaction temperature and pH were 60 and 4.0 ℃ respectively; it maintained good stability below 50 and at pH 3 ～7.
β-Glucosidase Construction of Expression Vector Expression Pichia pastoris
Lin-guo ZHAO Li-jin YOU, Li-jin YOU Fei LI Shi-yuan YU
College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037
国际会议
南京
英文
142-146
2010-10-22（万方平台首次上网日期，不代表论文的发表时间）