Characterization of melanin produced by a wild-type strain of Bacillus thuringiensis

The Journal of General and Applied Microbiology

Yinyue Deng¹  Jinhong Wang¹  Gaixin Ren¹  Yuehua Chen¹  Jun Cai¹ 

[1] Department of Microbiology, College of Life Sciences, Nankai University

关键词: Bacillus thuringiensis;    melanin;    UV protection;    wild type;   

DOI  :  10.2323/jgam.50.183

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

Bt L-7601 is a UV resistant wild-type strain, which belongs to Bacillus thuringiensis subsp. dendrolimus serotype H4a4b. It was isolated from nature, and produced a dark brown pigment during the exponential phase of growth. Bt L-7601 had the ability to produce pigment in a general nutrition-abundant medium, which had no L-tyrosine. The pigment was identified as melanin based on chemical testing, its light absorbance, and FT-IR analysis. Bt L-7601 has a strong resistance to UV light. After 30 min irradiation its survival rate was 17 times higher than that of the strain B. thuringiensis subsp. colmeri 15A3, which had no pigment. Results of the bioassays of residual insecticidal activity of Bt formulation with and without pigment produced by Bt L-7601 against larvae of Helicoverpa armigera and Spodoptera exigua after exposure to UV irradiation showed that the pigment is an excellent UV protective agent for the insecticidal proteins.

【 授权许可】

Unknown