Cloning And Analysis Of Pectate Lyase Gene And Construction Of Its Expression Vectors

Pectinase is a series of enzymes for degrading pectin. It is widespread in high plants and micro-organisms, while it can not be synthesized in zooblast. Pectinase includes the propectinase, pectin esters, pectin hydrolase and pectate lyase.Pectinase is one of the major commercial enzymes in the world. During recent years, pectinase has been widely used in the ungluing process of cotton and harl in the textile industry. The significant achievement has been obtained: it not only improves the quality of products, but also decreases the use of chemicals in the ungluing process, which results in the reducing of pollution. In addition, Pectinase has been of great value in food processing, feed processing, papermaking, inducing plant disease-resistance, improving wood antisepsis ability, gastrolith treatment and single-cell-food producing. Nowadays, pectinase used in industry is commonly obtained from microorganisms. As is reported, there are more than 40 kinds of microorganisms which can produce pectinase. The research and application are focused on the mildew pectinase whose enzyme system is more entire.Pectinase has been researched for a long time. A lot of research work has been done abroad in the field of molecular biology of pectinase in microorganisms. On the contrary, such work has rarely been done inland. Domestic research are focused on the screening of the bacteria strains, inducing variation and optimizing the conditions. With the development of biotechnology, the use of genetic engineering technology in bacteria screening and breeding has not only enhanced the yield of enzymes in bacteria, but also altered the character of enzymes, which concentrated a variety of beneficial properties in one bacteria strain. It has shortened the time from the research to application and overcome the blindness in the traditional breeding research.In this research, searching the alignment of pectin lyase in Genbank by BLAST tool, a pair of primers were designed according to the conservative sequence of the reported pectate lyase gene. The genomic DNA of a strain of bacteria which has the ability to degrade pectate was extracted, using which a 877bp segment was obtained by PCR. The results of Blastx showed that this fragment is 94% homology with the gene pectate lyase (pelC, Accession number: AJ132325) of Erwinia chrysanthemi. The nested primers were designed according to the sequence of the fragment obtained before and the AD primers were designed according to the different sequences of the pectate lyase obtained in...