PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
artículos
Título:
Dechlorination activity detection in Streptomyces sp M7
Autor/es:
CUOZZO, S.A.; CHAVARRÍA, C.N.; ROLLAN, G. C; ABATE, C.M.; AMOROSO, M.J
Revista:
JOURNAL OF BIOTECHNOLOGY
Editorial:
ELSEVIER
Referencias:
Lugar: AMSTERDAM; Año: 2008 p. 678 - 707
ISSN:
0168-1656
Resumen:
Abstract: The contamination with halogenated aliphatic compounds residues (as gamma-hexachlorocyclohexane) are often considered to be relatively recalcitrant because they can found in soil, water, air, plants, agricultural products, animals, food, and humans [1,2]. The lindane (gamma-hexachlorocyclohexane) is a lyphophilic compound, is considered a potential carcinogen and it is listed as priority pollutant by the US EPA. Little information is available on the ability of organochlorine pesticide biotransformation by  actinomycete species, the main group of bacteria present in soils and sediments [3]. However an indigenous isolated Streptomyces sp M7 strain demonstrated that it can grow in the lindane presence as only carbon sources [4]. The ability of actinomycetes to transform organochlorine pesticides has not been widely investigated, nevertheless the metabolic pathways for pesticide biodegradation by Gram negative bacteria have been more extensively studied than in Gram-positive bacteria, as the case of an aerobic degradation way of lindane until the mineralización by Sphingobium japonicum[5], where the first step is the dehalogenase activity to obtain pentachlorocyclohexene. The aim of this work is to determine if Streptomyces sp. M7 possess   the dehalogenase activity because so far there is no any information. Dehalogenase activity was measured using free-cell extract from Streptomyces sp. M7 cultured in flasks containing 30 ml liquid minimal medium supplemented with and without lindane 10 mg/1, on a rotatory shaker (100 rpm) at 30 ºC, for 96 h. Samples were centrifuged (9,900 g, 10 min), the cells were broken by the French Press and centrifuged. The supernatant was used by detecting the dechlorination reaction. The dechlorination activity was measured by spectrophotometer at 595 nm. Optimal temperature, pH were determined for optimizing the dechlorinase activity. The obtained results show that Streptomyces sp. M7 presents intracellular dechlorinase activity. It is also four-times more than the control.  On the other hand the best conditions for the dechlorinase activity are 30 ºC , alkaline pH (9.5).  These results show for the first time the presence of the dechlorinase activity in an actinomycete strain.