叶绿素降解工程菌株的构建

Construction of Chlorophyll Degradation Engineering Bacteria

为特异、高效地降解烟叶中的叶绿素,从模式植物拟南芥中克隆获得了叶绿素酶基因At CLH1片段,大小为975 bp。通过构建表达载体p ET28a-At CLH1,并转化大肠杆菌BL21,获得了重组工程菌株。该菌株在30℃下,经0.5 mmol/L IPTG诱导培养22 h,可较好地表达重组蛋白At CLH1,蛋白质电泳图谱显示其大小约为35 ku。该菌株的叶绿素酶活力可达24.9 U/m L,能够明显降解烟叶提取物中的叶绿素,在提升低次烟叶品质方面具有很好的应用前景。

For the specific and efficient degradation of chlorophyll in tobacco leaves, the chlorophyllase gene AtCLHl containing a full coding region of 975 bp was cloned from Arabidopsis thaliana. AtCLHl gene was cloned into vector pET28a,and the vector was then transformed into E. coli BL21 c e l ls , finally the recombinant engineering bacterium was obtained. After culturing under 30 °C for 22 h,the protein AtCLHl could express well with 0. 5 mmol/L IPTG （ isopropy-（3-D-thiogaIactopyranoside） as inducer. Sodium dodecyl sulfate（SDS） fingerprint results showed that the molecular mass of AtCLHl was 35 ku. The activity of AtCLHl was 24. 9 U/mL, which could degrade the chlorophyll in tobacco extract and had a good application prospect in improving the quality of low quality tobacco.