Cry genes profile and proteolytic activity of native Bacillus thuringiensis strains against Spodoptera frugiperda

Abstract

Introduction: Bacillus thuringiensis (Bt) produces entomopathogenic Cry proteins which are activated to pathogenic form by proteases. Objective: Determination of cry genes and proteolytic activity in three native Bt strains. Material and methods: Total DNA was isolated with the CTAB technique. Cry 1 and 2 genes were amplified with general and specifics primers. Proteolytic activity was assayed by using azocasein as substrate. Results and Discussion: Specific cry genes and the biomass-bound protease activity are showed in the table. Bt RT displayed different cry specific content than the others strains. In addition to Cry protein, Bt is also an excellent source of protease activities. Bt RT has a proteolytic activity significantly different to that achieved for the reference strain Bt 4D1 (P> 0.05, Tukey test). This work was supported by grants PICTO-UNT 761 and PIP 6062 (CONICET).