“AISLAMIENTO Y CARACTERIZACIÓN DE CEPAS DE BACILLUS THURINGIENSIS CON ACTIVIDAD MOSQUITOCIDA NATIVAS DE OAXACA”

Abstract

ABSTRACT This study demonstrated the potencial of the isolation and characterization of Bacillus thuringiensis Berliner in soil samples, animal droppings and cobwebs of Oaxaca, Mexico. 80% of the samples indicated the presence of B.thuringiensis. From 29 isolated corps-3 presented toxicity against Aedes aegypti. The effect on mosquito larvae in fourth instar Aedes aegypti was quantified by bioassay using the spore crystal and comparing it with standard B. thuringiensis subsp. israelensis. Of the three potential mosquitocida know two showed high levels of toxicity, which presented an LC50 of 10.82 and 13.20ng/ml respectively, similar to the standard Bti (9.43ng/ml). The isolated strains showed a pattern similar to the standard plasmids. And the PCR was positive for flagellin gene. The ultra structure paraespopales bodies indicated a similarity to the typical standard spherical crystal. These study demonstrated the existence of B. thuringiensis in Oaxaca, Mexico and it is the first record of these strains mosquitocidas in this state.