Chromium (VI) remediation by a native strain: effect of environmental conditions and removal mechanisms involved

GONZÁLEZ PAOLA SOLANGE; AMBROSIO LAURA FERNANDA; PAISIO CINTIA ELIZABETH; TALANO MELINA; MEDINA MARIA INES; AGOSTINI ELIZABETH

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Año: 2014 vol. 21 p. 13551 - 13559

0944-1344

Abstract A native bacterial strain with high capability for Cr(VI) removal was isolated from tannery sediments located inElena (Córdoba Province, Argentina). The strain was characterizedby amplification of 16S rRNA gene and identified asSerratia sp. C8. It was able to efficiently remove different Cr(VI) concentrations in a wide range of pHs and temperatures.The addition of different carbon sources as well as initialinoculum concentration were analyzed, demonstrating that Serratia sp. C8 could reduce 80 % of 20 mg/L Cr (VI) in a medium containing glucose 1 g/L, at pH 6?7 and 28 °C as optimal conditions, using 5 % inoculum concentration. The mechanisms involved in Cr (VI) removal were also evaluated. The strain was capable of biosorpting around 7.5?8.5 % of 20 mg/L Cr on its cell surface and to reduce Cr (VI). In addition, approximately a 54 and 46 % of total Cr was detectedin the biomass and in the culture medium, respectively, and in the culture medium, Cr (III) was the predominant species. In conclusion, Serratia sp. C8 removed Cr (VI) and the mechanisms involved in decreasing order of contribution were as follows: reduction catalyzed by intracellular enzymes, accumulation into the cells, and biosorption to the microbial biomass. This strain could be a suitable microorganism for Cr (VI) bioremediation of tannery sediments and effluents or even for other environments contaminated with Cr.