Cloning of a chitinase gene into Bacillus thuringiensis subsp. aizawai for enhanced insecticidal activity

The Journal of General and Applied Microbiology

Somsak Pantuwatana²  Amaret Bhumiratana¹  Watanalai Panbangred¹  Srisurang Tantimavanich¹ 

[1]Department of Biotechnology

[2]Microbiology, Faculty of Science, Mahidol University

关键词: Bacillus licheniformis;    Bacillus thuringiensis;    B.t.a.-toxicity;    chitinase;    delta-endotoxin;    Spodoptera exigua;   

DOI  :  10.2323/jgam.43.341

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

Chitinase from a high producing strain (TP-1) of Bacillus licheniformis was used with B. thuringiensis subsp. aizawai (B.t.a.) in a combined larvicidal assay against the pest, Spodoptera exigua. With 10mU of this chitinase, the LD50 of B.t.a. was reduced by 7.6, 13.8 and 15 times on days 3, 5 and 7, respectively when compared to use of B.t.a. alone. In addition, a combination of chitinase (10mU) and B.t.a. at a sub-lethal dose retarded growth and development of S. exigua. In preparation for transformation of B.t.a., the TP-1 chitinase gene was cloned in E. coli DH5α and sequenced to reveal a single open reading frame of 1, 815bp. This open reading frame encoded for a protein of 604 amino acids and a characteristic signal peptide sequence of 35 amino acids. The gene was subsequently introduced into B.t.a. where it was expressed constitutively. The transformed strain showed slightly improved activity against S. exigua when compared to the non-transformed strain. This was probably due to the low chitinase activity (15mU/ml) of the transformant, which might be improved by further gene manipulation to overexpress enzyme production.

【 授权许可】

Unknown