Detection of GAMA-PCCH and 1,4-TCDN in Streptomyces sp. M7cell-free extracts by the dechlorinase activity on degradation GAMA-HCH

Abstract

The Synthesis of dechlorinase in Streptomyces sp. M7 was induced when the microorganism was grown in the presence of lindane (g-HCH) as the only carbon source. Was grown in MM (minimum media) containing 100 mg ml-1 g-HCH and incubated at 30ºC for 48 and 96 h. The inoculum was started with spore suspension (109 c.f.u. ml-1). After incubation pellets were aseptically harvested by centrifugation. The cell-free extract was used for extraction of g-HCH, g-pentachlorocyclohexene (g-PCCH) and 1,3,4,6-tetrachloro-1,4-cyclohexadiene (1,4-TCDN).Were extracted by solid phase extraction using C18 columns, evaporated until dry underreduced pressure and the residue was resuspended in hexane. Routine quantitative determinations of lindane catabolism were carried out with gas chromatograph- electron capture detection-mass spectrometry analysis. The g-PCCH and 1,4-TCDN were detected, both being products of the dechlorinase activity from the cell-free extracts obtained at 48 and 96 h of growth of Streptomyces sp. M7 in MM with lindane revealed the appearance of g-PCCH (Rt 6.26 min) and 1,4-TCDN, (Rt 5.29 min), the first and second product of the lindane catabolism by the specific dechlorinase in the catabolic way proposed by Nagata. The relative abundance of g-PCCH and the 1,4- TCDN increased one and half times, at 96 h compared to 48 h of growth, these metabolites were not found in MM with lindane. The first time that the presence of an enzyme with dechlorinase activity has been demonstrated in an actinomycete strain isolated in Tucumán, Argentina.