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BioMed Research International
Volume 2013 (2013), Article ID 392573, 9 pages
http://dx.doi.org/10.1155/2013/392573
Research Article

Enhanced Removal of a Pesticides Mixture by Single Cultures and Consortia of Free and Immobilized Streptomyces Strains

1Planta Piloto de Procesos Industriales Microbiológicos (PROIMI-CONICET), Avenida Belgrano y Pasaje Caseros, 4000 Tucumán, Argentina
2Núcleo de Desarrollo Científico Tecnológico, Universidad de La Frontera, Avenida Francisco Salazar 01145, 4780000 Temuco, Chile
3Departamento de Ingeniería Química, Universidad de La Frontera, Avenida Francisco Salazar 01145, 4780000 Temuco, Chile
4Universidad del Norte Santo Tomás de Aquino, 9 de Julio 165, 4000 Tucumán, Argentina
5Unidad de Administración Territorial, Centro Científico Tecnológico, CONICET-Tucumán, Crisóstomo Álvarez 722, 4000 Tucumán, Argentina
6Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 491, 4000 Tucumán, Argentina

Received 24 April 2013; Revised 7 June 2013; Accepted 13 June 2013

Academic Editor: Kannan Pakshirajan

Copyright © 2013 María S. Fuentes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Pesticides are normally used to control specific pests and to increase the productivity in crops; as a result, soils are contaminated with mixtures of pesticides. In this work, the ability of Streptomyces strains (either as pure or mixed cultures) to remove pentachlorophenol and chlorpyrifos was studied. The antagonism among the strains and their tolerance to the toxic mixture was evaluated. Results revealed that the strains did not have any antagonistic effects and showed tolerance against the pesticides mixture. In fact, the growth of mixed cultures was significantly higher than in pure cultures. Moreover, a pure culture (Streptomyces sp. A5) and a quadruple culture had the highest pentachlorophenol removal percentages (10.6% and 10.1%, resp.), while Streptomyces sp. M7 presented the best chlorpyrifos removal (99.2%). Mixed culture of all Streptomyces spp. when assayed either as free or immobilized cells showed chlorpyrifos removal percentages of 40.17% and 71.05%, respectively, and for pentachlorophenol 5.24% and 14.72%, respectively, suggesting better removal of both pesticides by using immobilized cells. These results reveal that environments contaminated with mixtures of xenobiotics could be successfully cleaned up by using either free or immobilized cultures of Streptomyces, through in situ or ex situ remediation techniques.