Identification and analysis of the Bio-Reduction of Chromium (VI) by Pseudomonas Fluorescens

Abstract

This paper focuses on the identification and analysis of the ability of Pseudomonas fluorescens to reduce chromium (VI) in aqueous media. To develop this bio-reduction capability, microorganisms which potentially can grow in a medium containing up to 100 mg/L of chromium, were selected and used. In order to determine the extension of the reduction of hexavalent chromiun (VI) in lab water, samples of 20 and 50 mg/L were added with 5, 10 and 15 % of final inoculum, respectively to the volume of the samples. Inoculum had a population of approximately 12x108 CFU/mL. Results suggest the occurrence of reduction in all the samples studied. This reduction occurred significantly in the tests P-20.5, P-20.10 and P-20.15, which yielded a reduction of chromium (VI) of 3.6, 1.88 and 5.95 mg/L respectively, for samples P-50.5, P-50.10 and P-50.15 were obtained reductions of 2.36, 4.19 and 4.47 mg/L. The highest levels of bio-reduction were obtained in P- 20.15 and P-50.15 tests.