Biological removal of carcinogenic chromium(VI) using mixed Pseudomonas strains

Abstract

The contamination of soil and wastewaters with Cr(VI) is a major problem. It has been suggested that microbial methods for Cr(VI) reduction are better than chemical methods, as they do not add other ions or toxic chemicals to the environment. In this study an aerobic reduction of Cr(VI) to Cr(III) by employing mixed Pseudomonas cultures isolated from a marshy land has been reported. The role of chromium concentration, temperature, pH and additives on the microbial reduction of Cr(VI) has been investigated. NADH was found to enhance the rate of reduction of Cr(VI). Complete reduction of chromium(VI) has been possible even at chromium(VI) concentrations of 300 ppm. Ions like SO 4 2؊ and poly-phenols inhibited the metabolic activity relating to Cr(VI) reduction. Under optimal conditions 100 mg/L of Cr(VI) was completely reduced within 180 min.

Genetic correlation between chromium resistance and reduction inBacillus brevisisolated from tannery effluent

“…1987). Reduction of Cr(VI) to Cr(III) has been reported with many bacterial types (Shen and Wang 1993; Pal and Paul 2004; Aravindhan et al . 2007; Ma et al .…”

Microbial Fingerprinting of Potential Biodegrading Organisms

“…Microbial remediation of Cr (VI) by the implementing mixed cultures of Pseudomonas sp. was investigated by some researchers [8]. Few other fungal species like Aspergillus niger [143], Fusarium oxysporum NCBT-156 [7], Pichia anomala M10 [96], and Saccharomyces cerevisiae [94] could be able to remove Cr (VI).…”

Turning Waste to Resource: An Example of Dehydrogenation Catalyst Cr/ZrO2 Derived from Photoreduction Treatment of Chromium-Containing Wastewater with ZrO2

“…The production of chromium in China is only about 1% of its consumption . Various methods such as adsorption, − chemical precipitation, bacterial reduction, − ion-exchange resin, , photocatalytic reduction ,− have been developed to remove and recycle chromium contaminant from the waste stream. However, few of them are economically available and can lead to discharging water stream which meets with the stringent regulation.…”