中文摘要：

克隆出大肠杆菌编码葡萄糖脱氢酶（PQQGDH）的gcd基因,构建了诱导型表达载体pET28a-gcd,转化大肠杆菌E.coli BL21后获得阳性克隆菌株BL21/pET28a-gcd。IPTG诱导后,经SDS-PAGE分析表明,该工程菌PQQG-DH的表达量约为对照菌的18倍,约为18.2 mg/L,实现了高表达。此外,研究发现添加MgCl2能提高PQQGDH的表达量。

英文摘要：

The gcd gene-encoding pyrroloquinoline quinine（PQQGDH） has been cloned using the polymerase chain reaction（PCR） from E.coli BL21,and an inducible expression vector pET28a-gcd was constructed and transformed into E.coli BL21.Sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDS-PAGE） analysis showed a high expression of PQQGDH upon isopropyl β-D-1-thiogalactopyranoside（IPTG） induction（18.2 mg/L）,corresponding to a 18-fold increase compared with that in control strain.Addition of MgCl2 further enhanced the expression of PQQGDH.