BIOREMEDIATION OF METHOXYCHLOR BY NATIVE ACTINOMYCETES. EFFECT OF TEMPERATURE, pH AND PESTICIDE CONCENTRATION

CUOZZO, SERGIO A.; BOURGUIGNON, NATALIA; FUENTES, MARÍA S.; SÁEZ, JULIANA M.; BENIMELI, CLAUDIA S.; AMOROSO, MARÍA J.

Puerto Madryn

Congreso; XLVI Reunión Anual-Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010

  Methoxychlor (MTX) is an organochlorine pesticide. It was developed as a replacement for DDT and it was used in industrial and agricultural activities. MTX is a persistent, bioaccumulative, and toxic chemical and it was prohibited in countries, nevertheless it is even found as contaminate environmental. The aims of this work were selected an actinomycete strain available to degraded MTX and optimized the environmental conditions for these process. Streptomyces sp. M7, S. coelicolor A3 and four actinomycetes isolates of contaminated soil were cultivated in minimal medium with MTX (1,66 mg/L) as sole carbon source. Microbial growth, MTX remained and chlorine ions released were determined. The actinomycete selected was cultivated at different temperature, pH and MTX concentration conditions. The isolates were characterized by 16S rDNA amplifications and sequenced and they were identified as members of Streptomyces genus. Streptomyces A14 showed the best growing (0.39 mg/L), MTX remotion (100%) and chlorine released (DA540=0.14). Temperature of 30 ºC and pH 7 were the best conditions for MTX biodegradation by Streptomyces A14. Finally these strain obtained 97.6% of MTX removed at the higher MTX concentration (16.60 mg/L). Our results suggest that Streptomyces A14 has a big potential for bioremediation of MTX contaminated soils and these is the first evidence of aerobic MTX degradation.