Actinobacteria Consortia as Lindane Bioremediation Tool for Liquid and Soil Systems

Abstract

The current study was carried out to compare lindane degradation by pure and mixed cultures of indigenous Streptomyces strains. Cell free extracts were assayed for potentiating dechlorinase activity and, based on these results, consortia of two to six microorganisms were assayed for their growth on and degradation of lindane. Four actinobacteria, previously isolated from a pesticide-contaminated area, were selected because of their tolerance to lindane and their ability to use the pesticide as sole carbon source. These strains as well as Streptomyces sp. M7 and Streptomyces coelicolor A3 were used to study specific dechlorinase activity (SDA) and lindane removal in mixed cultures. Pure cultures presented SDA in the presence of lindane as carbon source. SDA was improved by certain mixed cultures until twelve times compared with pure cultures. Mixed cultures with two, three and four strains showed maximum lindane removal of 46 to 68%, whereas combinations of five and six strains did not efficiently remove the pesticide from the culture medium. The consortium of strains Streptomyces sp. A2, A5, M7 and A11 presented the lowest ratio between residual lindane concentration and SDA and could be a promising tool for lindane biodegradation. Furthermore, the role of bacterial consortium of lindane-degrading strains was examined in lindane decontamination soil and slurry assays, in which lindane removal percentages were 25 and 21 respectively.