Pesticides Removal Using Actinomycetes and Plants

ALVAREZ, A.; FUENTES, M.S.; BENIMELI CS; CUOZZO, S.A; SAEZ JM; AMOROSO M.J.

FUNGI AS BIOREMEDIATORS

Springer-Verlag

Año: 2013; p. 227 - 242

The present results clearly suggest that Streptomyces sp. M7 has the capacity to growth in a soil extract broth, a nutritionally poor medium, in the presence of lindane and to remove the pesticide. Since streptomycetes are metabolically diverse and relatively resistant to adverse conditions that may occur in the soil environment, Streptomyces sp. M7 could be considered as attractive targets for lindane degradation in situ. In addition, the development of bioremediation processes using indigenous microorganisms is advantageous, as strains isolated are already adapted to the substrate, and to local soil and climatic conditions, and regulatory and legislation issues are simpler, compared to the introduction and release of exogenous microorganisms and genetically modified organisms into the environment. On the other hand, Streptomyces sp. M7 bioremediation activity is not inhibited by the natural soil microbial flora. Moreover, Streptomyces sp. M7 growth was not inhibited by 300 g kg-1 of lindane. On the other hand, our results were the first report on dehalogenase activity in an actinomycete strain with lindane as specific substrate. This has only been reported in Sphingomonas and Frankia. In addition, we demonstrate that synthesis of the dechlorinase enzyme was induced by the presence of lindane and this activity was optimal in the culture medium at pH 7-9. Regarding the use of plants (or their products) for the treatment of contaminated sites, our preliminary results suggest that Streptomyces sp. M7 was stimulated by the root exudates of maize amended to the culture. In this context, phytostimulation may be a promising strategy for the remediation of HCH-contaminated soils. It is important to continue these studies not only at the laboratory but also in field trails in order to evaluate the potential of Streptomyces sp. M7 in the bioremediation of natural habitats. Further studies evaluating the soil-plant-microbe system and its influence on HCH biodegradation are necessary so as to better explore and exploit an undoubtedly huge potential.