环状芽孢杆菌几丁质酶基因序列分析、表达和生物活性测定

真菌病害一直是影响作物的主要病害之一 ,每年造成巨大经济损失。几丁质酶可水解许多病原真菌细胞壁所含有的主要成分—几丁质 ,是研究得最多的抗真菌蛋白质。许多几丁质酶基因已从微生物中克隆到 ,芽孢杆菌是一类重要的几丁质酶产生菌。环状芽孢杆菌可产生并分泌多种多糖降解酶类 ,包括几丁质酶、β 1 ,3 葡聚糖酶、β 1 ,6葡聚糖酶和半纤维素酶1] 。Ｗａｔａｎａｂｅ克隆了环状芽孢杆菌ＷＬ 1 2菌株的几丁质酶基因ｃｈｉＡ和ｃｈｉＤ ,对该几丁质酶基因的结构和功能进行了深入研究2～ 4 ] 。我国的陈三凤克隆了黄杆菌的几丁质酶基因 ,…

Study on the Sequence Analysis,Expression and Application of Chitinase Gene From Bacillus circulans

Sequence analysis of the chitinase gene cht1 of Bacillus circulans showed that it contained 2151 nucleotides,which codes the precursor of chitinase CHT1 with 717 amino acid residues.The nucleotide and deduced amino acid sequences of cht1 showed 81% and 95% homology with those of ChiA of B.circulans WL-12,respectively.The cht1 gene was cloned into the Escherichia coli-Bacillus subtilis shuttle vector pSUGV4 and two recombinant plasmids, named pUSCH1 and pUSCH2 which contained 2.9kb and 4.0 kb insert respectively,were obtained.The recombinant plasmids were transformed into B.subtilis DB104 and WB600.Chitinase activity was detected both in transformed E.coli and B.subtilis.The DB104/pUSCH1 strain was found to be effective in the bio-controlling the infection of Magnaporthe grisea under greenhouse condition,which showed 71.67% decrease in rice disease incidence.