Demonstration of the use of Scenedesmus and Carteria biomass to drive bacterial sulfate reduction by Desulfovibrio alcoholovorans isolated from an artificial wetland
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Date
2003-10
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Elsevier
Abstract
A major factor limiting application of bacterial sulfate reduction to removal of sulfate and heavy metals in wetland systems is the requirement to supply carbon and energy to drive the process. Primary production by aquatic plants and algae is a cheap option for driving sustainable bacterial sulfate reduction and most operational systems have relied on plants. The use of harvested, non-growing algal biomass to support bacterial sulfate reduction was investigated. Two genera of green algae, strains N9 and A3, were isolated from treatment cells from the Artificial Wetland Filter at the Ranger uranium mine (Northern Territory, Australia) which successfully removes UO22+, Mn2+ and nitrate, but little sulfate, from mine waters. These algae were identified as Carteria sp. and Scenedesmus sp. and were used as the sole carbon and energy source to enrich a sulfate-reducing mixed bacterial culture from the constructed wetland. Bacterial sulfate reduction supported solely by degradation of algal biomass was demonstrated at laboratory scale using both algae. In excess of 300 mg/L, sulfate was reduced in 17 days following an initial period of approximately 8 days during which sulfate levels did not decrease. The amount and rate of reduction was shown to be dependent on the concentration of algal biomass added. Carteria algae at low concentration showed reduction earlier; however, yields at higher concentration were affected by unknown inhibition. Scenedesmus strain N9 produced a maximum specific yield of 94.3 g of sulfate reduced per gram biomass added compared with 43.5 for Carteria strain A3. Sequence analysis of the 16S rRNA gene of members of the bacterial consortium indicated that the sulfate-reducing bacteria (SRB) showed highest homology (98.5%) with Desulfovibrio alcoholovorans. A second bacterium, which showed homologies of 91–92% with organisms of the Clostridial assemblage, was also present in the culture and represents a new species, or possibly a new genus. Crown Copyright 2003 Published by Elsevier B.V.
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Keywords
Biomass, Sulfate-reducing Bacteria, Wetlands, Algae, Carbon, Organic matter, Heavy metals, Microorganisms
Citation
Russell, R. A., Holden, P. J., Wilde, K. L., & Neilan, B. A. (2003). Demonstration of the use of Scenedesmus and Carteria biomass to drive bacterial sulfate reduction by Desulfovibrio alcoholovorans isolated from an artificial wetland. Hydrometallurgy, 71(1-2), 227-234. doi:10.1016/S0304-386X(03)00160-9