Actinobacteria Consortium as a Tool for Methoxychlor Remediation, in Soil and Slurry Systems

FUENTES, MARÍA S.; BENIMELI, CLAUDIA S.; AMOROSO, MARÍA J.

Puerto Vallarta

Simposio; 16th International Symposium on the Biology of Actinomycetes (ISBA16); 2011

Methoxychlor (MTX) is a pesticide developed for DDT replacement, which has been prohibited internationally since the 1970s due to its high toxicity. MTX is considered toxic, estrogenic and resistant to biodegradation. The bioremediation offers the possibility to destroy this toxic pollutant using biological activity and the use of actinobacteria is an attractive approach because of their ability to degrade pesticides. In the environment, organic compounds degradation is often carried out by mixed microbial communities. One of the best options for soils bioremediation and polluted sediments is their treatment through slurry bioreactors. The aim of this work was to evaluate the MTX removal capacity by a defined actinobacteria mixed culture under control laboratory conditions in soil and slurry systems.Streptomyces sp. A6 , Streptomyces sp. A12 , Streptomyces sp. A14 and Streptomyces sp. M7, previously selected for its ability for remove MTX, were individually pre-cultivated (72h) in minimal medium (MM) with MTX (1.66 mg L- 1) for its acclimation. Then, these strains were inoculated as a consortium, 28 days in soil and 7 days in slurry systems (with or without stimulation). Both tests were carried out in presence of MTX (1.66 mg L-1) or without this toxic as biotic control at 30 °C. The growth of this consortium was determinate as CFU/g of soil or as CFU/mL of slurry, and residual MTX was measured by gas chromatography (GC/mEDC).In soil and slurry systems, the growth was similar in both tests, but the generation times in slurry systems (3.5h) were significantly lower than in soils systems (17.3h). The MTX remotion percentage in the slurry-stimulation system (56.19%) was better than without stimulation (45.58%) and similar to MTX remotion percentage in soil system (56.43%).This actinobacteria consortium has the ability to grow and removes MTX in soil and in slurry systems and could be a promising tool for the bioremediation of MTX in processes ex-situ or in-situ.