Organic Carbon Utilisation by Iron(II)-Oxidising Bacteria Sulfobacillus thermosulfidooxidans and Alicyclobacillus Strain FP1 that Inhabit Copper Sulfide Leaching Heaps

Abstract:

Strains of Sulfobacillus (S.) and Alicyclobacillus species have been identified/detected in managed bioleaching heaps and agitated tanks using culture-dependent and culture-independent methods. S thermosulfidooxidans oxidises both iron(II) and reduced inorganic sulfur compounds (RISC). Several strains were isolated from a copper sulfide heap in North Western Australia. Alicyclobacillus strain FP1 (FP1) was also isolated from the heap and oxidises iron(II) but not RISC. However, the species exhibit differentiating characteristics during growth on D-glucose, which has been explored using a suite of monitoring and measurement techniques. As examples, a growth factor (yeast extract) is essential for FP1 but not for S. thermosulfidooxidans, although yeast extract is beneficial to the latter. FP1 grows well on glucose, compared with the poor-to-no growth of S. thermosulfidooxidans on the substrate. Solution pH strongly influences the activity of both species when grown on organic substrates, suggesting a pivotal role for solution acidity in the growth and activity of heterotrophs or mixotrophs in heap leach systems. This research forms part of an ongoing development of a data base with which to interpret the impacts of leaching conditions in heaps on microbial activity without having to disrupt metal production by invasive sampling campaigns. The insights gained will assist in understanding the effects that changing conditions in heaps due to acid consumption and/or increased element concentrations in process water may have on microbial activity.

• Periodical: Advanced Materials Research (Volume 1130)
• Pages: 218-221
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1130.218
• Online since: November 2015
• Authors: Denis W. Shiers, David M. Collinson, Helen R. Watling
• Keywords: Alicyclobacillus, Heap Leaching, Organic Carbon, Sulfobacillus thermosulfidooxidans

References

[1] H.R. Watling: Hydrometallurgy Vol. 84 (2006), 81–108.

[2] H.R. Watling, E.L.J. Watkin, D.E. Ralph: Environmental Technology Vol. 31 (2010), 915–933.

[3] D.W. Shiers, D.E. Ralph, H.R. Watling: Biochemical Engineering Journal Vol. 54 (2011), 185–191.

[4] G. Deinhard, J. Saar, W. Krischke, K. Poralla: System. Appl. Microbiol. Vol 10 (1987), 68–73.