Abstract
An enrichment consortium and an isolate (isolate TKW) of sulfate-reducing bacteria (SRB) have been obtained from metal-contaminated marine sediments of Tokwawan, Hong Kong SAR. These bacteria are capable of reducing highly toxic and soluble hexavalent chromium (Cr6+) enzymatically into less toxic and insoluble trivalent chromium (Cr3+) under anaerobic conditions. The enrichment consortium almost completely (98.5%) reduced 0.6 mM Cr6+ in 168 h and the rate of reduction was 0.5 g (Cr6+) g (protein) -1 h-1. In comparison, with Cr6+ as the sole electron acceptor (as a surrogate for SO42-), isolate TKW reduced 94.5% of the initially added Cr6+ (0.36 mM) in 288 h, with the rate of 0.26 g (Cr6+) g (protein)-1 h-1. Adsorption by these bacteria was not the major mechanism contributing to the transformation or removal of Cr6+. The biomass and Cr3+ in the cultures increased simultaneously with the reduction of Cr6+. These indigenous SRB might have potential application in bioremediation of metal contaminated sediments.
| Original language | English |
|---|---|
| Pages (from-to) | 1523-1529 |
| Number of pages | 7 |
| Journal | Chemosphere |
| Volume | 52 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2003 |
| Externally published | Yes |
Keywords
- Bioremediation
- Hexavalent chromium
- Marine enrichment consortium
- Metal reduction
- Sole electron acceptor
- Sulfate-reducing bacteria
