Lindane Removal Induction by Streptomyces sp M7

BENIMELI C.S.; CHAILE P; CASTRO G.R.; AMOROSO M.J.

JOURNAL OF BASIC MICROBIOLOGY

WILEY-VCH Verlag GmbH & Co. KGaA

Año: 2006 vol. 46 p. 348 - 357

0233-111X

Gamma-hexachlorocyclohexane (ã-HCH or lindane), one of the most commonly used pesticides, hasbeen mainly used in agriculture; this pesticide is known to be highly toxic and persistent, causingserious water and soil contamination. The objective of the present work is to study the effect of lowglucose concentration and the addition of lindane at different growing time on the pesticidedetoxification ability of Streptomyces M7.After 96 h of incubation in synthetic medium containing glucose 0.6 g l–1 with the addition oflindane 100 ìg l–1 at 20 h of incubation, a typical diauxic curve was obtained: glucose was thepreferred substrate until 24 h, at 48 h, when the carbohydrate was depleted, the microorganismconsumed the pesticide like carbon source. On the other hand, lindane removal induction wasobserved, which was greater when the pesticide was added to the medium at 20 h than 6 h ofincubation. Between 72 and 96 h, a maximum of ~86% of the Cl– was released when lindane wasadded to the medium at 20 h, whereas ~70% and 67% Cl– was released in the medium when thepesticide was added at 0 and 6 h of incubation respectively. This is the first report of chloride releasefrom inoculated medium supplemented with lindane, suggesting that the pesticide was degraded byStreptomyces sp. under aerobic conditions.