Molecular detection of enzymes involved in degradation of g--HCH by Streptomyces sp. M7.

CUOZZO, S.A.; BENIMELI, C.S.; AMOROSO, M.J.; ABATE, C.M.

Rosario, Santa Fe, Argentina

Congreso; XLII Reunion Anual de la Sociedad Argentina de Investigaciones en Bioquimica y Biologia Molecular (SAIB).; 2006

Sociedad Argentina de Investigaciones en Bioquimica y Biologia Molecular (SAIB).

The presence of linB and linC genes, which participate in the g-hexachlorocyclohexane (g-HCH) degradation was studied in Streptomyces M7. This strain can grow in culture medium with g-HCH as only carbon source. Streptomyces sp. M7 was grown in MM medium with and without g-HCH 100 mg L-1. A protein band, using SDS-PAGE, of approximately 66,2 kDa was detected in the cell-free extract; this band was not present when the microorganism was grown without the pesticide. Plasmids have not been detected by alkaline lysis procedure and by Pulsed Field Gel Electrophoresis (PFGE). These results suggest that genes encoding pesticide degradation enzymes could be localized in chromosomal DNA. PCR amplifications of linB and linC genes, that codify for g-pentachlorocyclohexane hydrolytic dehalogenase and 2,5-dichloro-2,5-cyclohexadiene-1,4-diol dehydrogenase respectively, were carry out using oligonucleotide designed based of the gene sequences involved in g-HCH degradative pathway of Sphingobium japonicum UT26 and Microbacterium sp. ITRC1. The size of amplification fragments obtained were according to the expected. These results show for the first time that Streptomyces M7 could has specific enzymes for degrading of g-HCH.