Detection of ƒÔ-PCCH and 1,4-TCDN in Streptomyces cell-free extracts by the dechlorinase onƒÔ-HCH

SERGIO A. CUOZZO; CARLOS M. ABATE; MARÍA J. AMOROSO

San Miguel de Tucumán, Argentina

Congreso; XLV Reunión Anual de la (SAIB); 2009

Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular

The synthesis of dechlorinase in Streptomyces sp. M7 was induced when the microorganism was grown in the presence of lindane (d- HCH) as the only carbon source. It was grown in MM medium containing 100 mg ml-1 d-HCH and incubated at 30 ºC for 48 and 96 h. After incubation, pellets were aseptically harvested by centrifugation. The cell-free extract was used for extraction of d-HCH, d- pentachlorocyclohexene (d-PCCH) and 1,3,4,6-tetrachloro-1,4- cyclohexadiene (1,4-TCDN). They were extracted by solid phase extraction using C18 columns 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 d-PCCH and 1,4-TCDN were detected, both being products of the dechlorinase activity from the cell-free extract at 48 and 96 h of growth of Streptomyces sp. M7 in MM with lindane. The appearance of d-PCCH (Rt 6.26 min) and 1,4-TCDN, (Rt 5.29 min), the first and second product of the lindane catabolism by a specific dechlorinase was proposed by other researchers in Sphingomonas. The relative abundance of both increased one and half times, at 96 h compared to 48 h of growth. Were not found in MM with lindane. This is the first time that an enzyme with dechlorinase activity has been demonstrated in an actinomycete strain isolated in Tucumán, Argentina.