Proteomic analysis of the influence of Cu2+ on the crystal protein production of Bacillus thuringiensis X022

Microbial Cell Factories

Research

Meifang Quan¹  Yunjun Sun¹  Xuemei Liu¹  Qi Yang¹  Liqiu Xia¹  Jie Rang¹  Xuezhi Ding¹  Mingxing Zuo¹  Shengbiao Hu¹  Hao He¹  Ting Wang¹  Shuang Liu¹ 

[1] College of Life Science, Hunan Provincial Key Laboratory of Microbial Molecular Biology-State Key Laboratory Breeding Base of Microbial Molecular Biology, Hunan Normal University, 410081, Changsha, China;

关键词: Bacillus thuringiensis;    Cu;    Insecticidal crystal proteins;    Proteome;    PhaR;   

DOI  :  10.1186/s12934-015-0339-9

 received in 2015-05-01, accepted in 2015-09-11,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundBacillus thuringiensis X022, a novel strain isolated from soil in China, produces diamond-shaped parasporal crystals. Specific mineral nutrients, such as Mg, Cu, and Mn, influence insecticidal crystal proteins (ICP) expression and the effects of these elements vary significantly. However, the molecular mechanisms of the effects caused by mineral elements have yet to be reported.ResultsThe ICP are mainly composed of Cry1Ca, Cry1Ac, and Cry1Da, which have molecular weights of about 130 kDa. ICP production was most efficient when Cu2+ was added at concentrations ranging from 10−6 to 10−4 mol/L at an initial pH of 8.0. Addition of Cu2+ also evidently increased the toxicity of fermentation broth to Spodoptera exigua and Helicoverpa armigera. After analyzing changes in proteome and fermentation parameters caused by Cu2+ addition, we propose that Cu2+ increases PhaR expression and consequently changes the carbon flow. More carbon sources was used to produce intracellular poly-β-hydroxybutyrate (PHB). Increases in PHB as a storage material bring about increases of ICP production.ConclusionsBacillus thuringiensis X022 mainly expresses Cry1Ca, Cry1Ac, and Cry1Da. Cu2+ increases the expression of Cry1Da, Cry1Ca, and also enhances the toxicity of fermentation broth to S. exigua and H. armigera.

【 授权许可】

CC BY   
© Liu et al. 2015