Comparative study of single and mixed cultures of actinobacteria for the bioremediation of co-contaminated matrices

Abstract

With the aim of comparing the behavior of single and mixed cultures of actinobacteria for the removal of chromium and lindane from different co-contaminated systems, the actinobacteria Streptomyces sp. M7, MC1, A5 and Amycolatopsis tucumanensis DSM 45259 were assayed as simple, double, triple, and quadruple cultures in minimal medium and soil artificially polluted with Cr(VI) and lindane. In liquid medium, Streptomyces sp. MC1 and the quadruple consortium reached the highest Cr(VI) and lindane removal (94% and 52%, respectively, in both cultures), although they did not present statistically significant differences in Cr(VI) removal respect to six other consortia. The best removal of bioavailable chromium and lindane from artificially contaminated soil were achieved by Streptomyces sp. M7 (50% and 60%, respectively) and the quadruple consortium (60% and 55%, respectively). The bioassay with Lactuca sativa demonstrated the success of the bioremediation in soil by Streptomyces sp. M7 and the quadruple consortium through an increase in the vigor index measured in lettuce seedlings compared to non-treated soil. The quadruple consortium demonstrated to be appropriate to bioremediate Cr(VI) and lindane co-contaminated both liquid and soil systems. The viability of the four strains after the bioremediation process was confirmed. These results represent an approximation for conducting a field-scale bioremediation strategy.