富含古罗糖醛酸的褐藻多糖生产菌株的构建  

Construction of high-guluronate-containing-alginate producing mutant of Pseudomonas sp.QDA

作　　者：胡斌[1] 韩峰[1] 林育姿[1] 宫倩红[1] 于文功[1] 

机构地区：[1]中国海洋大学医药学院教育部海洋药物重点实验室,山东青岛266003

出　　处：《海洋科学》2008年第1期14-18,共5页Marine Sciences

基　　金：国家自然科学基金资助项目(30371683)

摘　　要：为获得古罗糖醛酸(Guluronate)含量高的细菌胞外褐藻多糖,利用PCR从海洋细菌Pseudomonassp.QDA中克隆了其甘露糖醛酸C-5差向异构酶基因(algG),连接入质粒pMF 54Km,构建了重组表达载体pMF54 Km-algG。利用三亲接合法将pMF54 Km-algG转入菌株QDA中,获得algG过量表达重组菌株QDA-G1。H-NMR测定结果表明,QDA-G所产的褐藻多糖中β-D-甘露糖醛酸(M)与它的C-5差向异构体α-L-古罗糖醛酸(G)的比值为0.38,G的质量分数达到74.2%,比野生菌株QDA提高了26.4%。且重组菌株遗传稳定性良好,连续传代20代后,M/G的比值无明显变化。Pseudomonas sp. QDA, which was isolated from seawater, has the ability of producing extracellular alginate. In order to obtain the high-guluronate-containing alginate, C-5-mannuronan epimerase gene （algG） of Pseudomonas sp. QDA was cloned by PCR and ligated in to plasmid pMF54Km. The resulting plasmid pMF54Km-algG was transferred to QDA by triparental mating, and an algG over-expresslng strain, QDA-G, was obtained. The results of 1H-NMR showed that the M/G ratio of alginate fragments by QDA-G was 0.38 and the content of guluronate was 74.2%, about 26.4% higher than that of wild strain QDA. The genetic stability of QDA-G was good. No significant changes were found in M/G ratio of algi- nate fragments of QDA-G after 20 passages.

关 键 词：甘露糖醛酸C-5差向异构酶 假单胞菌 褐藻多糖 过量表达 

分 类 号：Q539[生物学—生物化学]