Expression of parasporal crystal protein (δ-endotoxin) gene(s) of Bacillus thuringiensis var. israelensis in sporogenic and asporogenic mutant strains of Bacillus cereus.

ABSTRACT

The expression of parasporal crystal protein (δ-endotoxin) coding gene(s) of Bacillus thuringlensis var. israelensis and its association, if any, with sporulation was studied in sporogenic Bacillus cereus and its asporogenic mutant strains. Five asporogenous mutants of Bacillus cereus blocked at different stages of sporulation, were isolated from a streptomycin-resistant strain, The transconjugants isolated from the plasmid transfer experiments between Bacillus thuringiensis var. israelensis and streptomycin resistant Bacillus cereus and its asporogenous mutants, showed larvicidal activity. The crystal protein gene(s) are, therefore, expressed both in sporulating and in non-sporulating mutant strains of Bacillus cereus suggesting that the expression of crystal protein gene(s), is independent of sporulation specific functions in Bacillus cereus.