Screening and characterization of Bacillus thuringiensis isolates from Brazil for the presence of coleoptera-specific cry genes

Forty-three Bacillus thuringiensis isolates from Brazil and 3 from Agentina were screened, using the polymerase chain reaction (PCR), for various cole optera-specific cry genes. Seven isolates produced specific and/or nonspeci fic DNA fragments in a PCR reaction with primers specific for two coleopter an cry genes and 4 of these produced DNA fragments with primers specific fo r 7 known coleopteran cry genes. These isolates showed, by electron microsc opy, the presence of spherical crystals. They also showed proteins of aroun d 70 kDa which were immunologically similar to the Cry3Aa protein from B. t huringiensis subsp. tenebrionis. The 3 isolates from Argentina were toxic t o T. molitor, and although no isolate from Brazil showed toxicity, they mig ht show toxicity to another insect species.