Resumo

GALVIS, Fabián  e  YOLIMA MORENO, Laura. Molecular  characterization  using rep-PCR of native isolates of Bacillus thuringiensis, obtained from soil samples. Agron. Costarricense [online]. 2014, vol.38, n.1, pp.223-229. ISSN 0377-9424.

Bacillus thuringiensis is a Gram-positive bacteria forming spores, which produces parasporal crystals of a proteic nature, toxic against various  orders  of  insects  and  biodegradable and  harmless to other species. This research use the experimental model, allowing, through observation techniques, microbiological and biochemical identification of B thuringiensis from soil samples from municipalities of Cúcuta, El  Zulia, Los Patios, San Cayetano and Villa del Rosario, Norte de Santander, Colombia, and its subsequent characterization with molecular markers Bc-Rep and MB1. Microbiological and biochemical tests identified 10 isolates as B. thuringiensis; the results of phylogenetic analysis showed significant differences in the clusters obtained with Bc-Rep and MB1 markers. With Bc-Rep a low index of similarity (18%) was recorded, while with the marker MB1 a higher similarity index, 58%, was obtained. This work indicated a great genetic variability among isolates, showing that markers Bc-Rep and MB1 are highly effective to differentiate closely related strains, thus becoming a genetic tool of great value for studies of identification and diversity in B. thuringiensis.

Palavras-chave : B. thuringiensis; bioinsecticide; rep-PCR; phylogenetic analysis.

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