Methoxychlor bioremediation by defined consortium of environmental Streptomyces strains

FUENTES, MARÍA S.; ALVAREZ, ANALÍA; SÁEZ, JULIANA M.; BENIMELI, CLAUDIA S.; AMOROSO, MARÍA J.

INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY

CTR ENVIRONMENT & ENERGY RESEARCH & STUDIES

Lugar: New York; Año: 2014 p. 1147 - 1156

1735-1472

Methoxychlor is an organochlorine pesticide used worldwide against several insect pests, resulting in human exposure. This pesticide mimics endocrine hormone functions, interfering with normal endocrine activity in humans and wild-life. For this reason it is imperative to develop methods to remove this pesticide from the environment, and though bioremediation using microorganisms results an excellent strategy. Five Streptomyces sp. strains previously isolated from organochlorine-polluted sites and capable to grow and remove methoxychlor, were combined as different mixed cultures to increase methoxychlor removal. From the 39 consortia tested, one consortium (Streptomyces sp. A6, A12, A14, M7) was selected because of its high pesticide removal and specific dechlorinase activity to be assayed on slurry and soil systems. This consortium showed higher biomass values (8.3 x 106 ± 5.7 x105 CFU mL-1) and methoxychlor removal (56.2% ± 2.3%) on enriched slurry than in non-enriched slurry (7.3 x 105 ± 1.2 x 105 CFU mL-1 and 45.6% ± 7.4% of pesticide removal). In soil systems, Streptomyces consortium showed higher growth (1.0 x 1011 ± 5.0 x 1010 CFU g-1) than in enriched slurry, although differences in methoxychlor removal between both culture conditions were not statistically significant. Therefore, the selected Streptomyces consortium may be suitable for development of in situ (soil) and ex situ (slurry bioreactor) bioremediation methods because of their potential to remove methoxychlor from different systems.