Evidence of a-, b- and c-HCH mixture aerobic degradation by the native actinobacteria Streptomyces sp. M7

SINELI P; TORTELLA G; DAVILA COSTA JS; BENIMELI C.S.; CUOZZO S.A

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2016 vol. 32 p. 81 - 90

0959-3993

The organochlorine insecticide c-hexachlorocyclohexane(c-HCH, lindane) and its non-insecticidal aandb-isomers continue to pose serious environmental andhealth concerns, although their use has been restricted orcompletely banned for decades. In this study we report thefirst evidence of the growth ability of a Streptomyces strainin a mineral salt medium containing high doses of a- andb-HCH (16.6 mg l-1) as a carbon source. Degradation ofHCH isomers by Streptomyces sp. M7 was investigatedafter 1, 4, and 7 days of incubation, determining chlorideion release, and residues in the supernatants by GC withlECD detection. The results show that both the a- andb-HCH isomers were effectively metabolized by Streptomycessp. M7, with 80 and 78 % degradation respectively,after 7 days of incubation. Moreover, pentachlorocyclohexenesand tetrachlorocyclohexenes were detected asmetabolites. In addition, the formation of possible persistentcompounds such as chlorobenzenes and chlorophenolswere studied by GC?MS, while no phenolic compoundswere detected. In conclusion, we have demonstrated for thefirst time that Streptomyces sp. M7 can degrade a- andb-isomers individually or combined with c-HCH and couldbe considered as a potential agent for bioremediation ofenvironments contaminated by organochlorine isomers.