Statistical evaluation of medium components of entomopathogenic protein production

Abstract

Bacillus thuringiensis produces proteins with entomopathogenic action. Advances in the production of bio-insecticides involve the application of suitable fermentation technologies, especially with the use of appropriate media, overcoming the metabolic limitations of the microorganisms. The use of agro-industrial residues as substrate in the production by fermentation can significantly reduce the final price and add value to low-cost materials. The objective of the present work was to screening substrates that have a positive impact on the production of entomopathogenic proteins from Bacillus thuringiensis RT. Evaluation was performed by Plackett-Burman experimental design. Eleven medium components were evaluated. Mortality bioassays were carried out using 3rd instar larvae of Spodoptera frugiperda. The most significant variables affecting positively the production were starch, milk powder and whey. Medium with highest protein production (0,8 mg/ml) was 4 times better than Luria Bertani medium (0,2mg/ml). There were significant differences in mortality with the media tested. In conclusion, many substrates were identified to improve production, which could be considered for optimization medium and studies inbioreactors.This work was supported by grants PIP-CONICET 297 and CIUNT 26/D409.