Versatility of Streptomyces sp M7 to bioremediate soils co-contaminated with Cr(VI) and lindane

APARICIO JD; SIMÓN SOLÁ MZ; BENIMELI CS; AMOROSO MJ; POLTI MA

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2015 vol. 116 p. 34 - 39

0147-6513

The aim of this work was to study the impact of environmental factors on the bioremediation of Cr(VI) and lindane contaminated soil by an actinobacterium Streptomyces sp. M7, in order to optimize the process. Soil samples were contaminated with 25 g Kg-1 of lindane and 50 mg Kg-1 of Cr(VI) and inoculated with Streptomyces sp. M7. The lowest inoculum concentration wichh simultaneously produced highest removal of Cr(VI) and lindane was 1 g Kg-1. The influence of physical and chemical parameters was assessed using a full factorial design. The factors and levels tested were: Temperature: 25, 30, 35 ºC; Humidity: 10%, 20%, 30%; Initial Cr(VI) concentration: 20, 50, 80 mg Kg-1; Initial lindane concentration: 10, 25, 40 g Kg-1. Streptomyces sp. M7 exhibited strong versatility, showing the ability to bioremediate co-contaminated soil samples at several physicochemical conditions. Streptomyces sp. M7 inoculum size was optimized. Also, it was fitted a model to study this process, and it was possible to predict the system performance, knowing the initial conditions. Moreover, optimum temperature and humidity condition for the bioremediation soil with different concentrations of Cr(VI) and lindane were determined. Lettuce seedlings were a suitable biomarker to evaluate the contaminants mixture toxicity. Streptomyces sp. M7 carried out a successful bioremediation, which was demonstrated through ecotoxicity tests with Lactuca sativa.