Autor(es): Promdonkoy, B.; Chewawiwat, N.; Tanapongpipat, S.; Luxananil, P.; Panyim, S.

Resumo: The cytolytic'-endotoxin gene from Bacillus thuringiensis subsp. darmstadiensis was amplified from genomic DNA by PCR by using primers designed from the sequence of cyt2Aa1 gene of B. thuringiensis subsp. kyushuensis. DNA sequence analysis revealed an open reading frame translating to a 259-amino acid sequence. The cloned gene was designated cyt2Aa2. This gene was highly expressed in Escherichia coli as inclusion bodies that could be solubilized in 50 mM Na sub(2)CO sub(3), pH 10.5. Activation of the solubilized protoxin by proteinase K (1% wt/wt, proteinase K/protoxin) yielded the active fragment of about 23 kDa. Cyt2Aa2 showed high hemolytic activity against sheep erythrocytes (hemolytic end- point 0.25 7g/ml) and was toxic to Culex quinquefasciatus and Aedes aegypti larvae (LC sub(50) 0.5-1.0 7g/ml).

Palavras-Chave: Biological control; Nucleotide sequence; Erythrocytes; Microbiology; Toxicity tests; Aquatic insects; Endotoxins; Hemolysis; Toxins

Imprenta: Current Microbiology, v. 46, n. 2, p. 94-98, 2003.

Descritores: Aedes aegypti - DNA

Data de Publicação: 2003