Batch studies were conducted to evaluate the effect of environmental factors on the rate of Cr(VI) reduction by two organisms, Bacillus sp. (a new isolate), and Pseudomonas fluorescens LB 300. Both organisms utilized glucose for Cr(VI) reduction under aerobic conditions. Higher Cr(VI) reduction rates were obtained with higher initial cell concentrations, but the specific rate (normalized against initial cell concentration), was higher at lower initial cell concentrations. The rate of Cr(VI) reduction by Bacillus sp. increased with initial Cr(VI) concentrations ranging from 20 to 70 mg/l and decreased at higher concentrations. The rate of Cr(VI) reduction by LB 300 steadily increased with the initial Cr(VI) concentrations over the entire test range of 20-100 mg/l Cr(VI). Further studies with the new isolate, Bacillus sp., showed that neither sulfate nor nitrate affected Cr(VI) reduction. Also no correlations were found between the rate of Cr(VI) reduction and the redox potential of culture media. Experiments with cell-free extracts of Bacillus sp. indicated that soluble type of enzymes were responsible for Cr(VI) reduction in this organism.
|Number of pages
|Published - Nov 1995
Bibliographical noteFunding Information:
Acknowledgements The information described in this article has been funded, in part, by the U.S. Environmental Protection Agency by an exploratory research grant awarded to Yi-Tin Wang under agreement No. R-816872-01-0. However, it has not been subjected to the Agency's required peer and administrative review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. The authors wish to thank Lawrence Bopp for donating his isolate, Pseudomonas fluorescens LB 300; Alan Bowers for sending chromium contaminated soils; and Hai Shen for his assistance in data collection and analysis.
- electron donor
- redox potential
ASJC Scopus subject areas
- Water Science and Technology
- Ecological Modeling
- Waste Management and Disposal
- Environmental Engineering
- Civil and Structural Engineering