Article

Ferroplasma cupricumulans sp nov., a novel moderately thermophilic, acidophilic archaeon isolated from an industrial-scale chalcocite bioleach heap

Murdoch University, Perth City, Western Australia, Australia
Extremophiles (Impact Factor: 2.17). 01/2007; 10(6):525-30. DOI: 10.1007/s00792-006-0527-y
Source: PubMed

ABSTRACT A new species of Archaea was isolated from an industrial mineral sulphide bioleach heap. Strain BH2, a non-motile pleomorphic coccus, was capable of chemomixotrophic growth on ferrous sulphate and yeast extract. Growth was not supported in the absence of yeast extract. Phylogenetic analysis based on the 16S rRNA gene showed that strain BH2 was most closely related to the species Ferroplasma acidiphilum; however, it showed only 95% sequence similarity with this species. Strain BH2 had a temperature optimum of 53.6 degrees C and a temperature range for growth between 22 and 63 degrees C. Thus, it is the first moderately thermophilic member of the genus Ferroplasma. The optimum pH for the growth of the strain occurred between pH 1.0 and 1.2 and the lowest pH at which growth was observed was 0.4. Based on 16S rRNA gene sequence analysis and other physiological characteristics, strain BH2 constitutes a new species within the genus Ferroplasma. The name Ferroplasma cupricumulans is proposed for the new species and strain BH2 (DSM 16651) is proposed as the type strain.

0 Followers
 · 
122 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: With a projected steady decline of gold ore grade in mineral resources, mining applications enabling efficient metal extraction from low-grade ores are of increasing interest to the minerals industry. Microbial processes may provide one such solution since they can participate in the biogeochemical cycling of gold in many direct and indirect ways. This review examines current literature on the role of microorganisms in gold processing and recovery. The review covers aspects such as the biotechnical pre-treatment of gold ores and concentrates, microbially catalysed permeability enhancement of ore bodies, gold solubilisation through biooxidation and complexation with biogenic lixiviants, and microbially mediated gold recovery and loss from leach liquors.
    Hydrometallurgy 02/2014; 142:70–83. DOI:10.1016/j.hydromet.2013.11.008 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Three kinds of samples (acid mine drainage, coal mine waste water and thermal spring) derived from different sites were collected in China. Thereafter, these samples were combined and then inoculated into a basal salts solution in which different substrates (ferrous sulfate, elemental sulfur or chalcopyrite) served as energy sources. After that, the mixed cultures growing on different substrates were pooled equally, resulting in a final mixed culture. After being adapted to gradually increasing pulp densities of flotation chalcopyrite by serial sub-culturing for more than two years, the final culture was able to efficiently leach the chalcopyrite at a pulp density of 20% (w/v). At that pulp density, the culture extracted 60.4% of copper from the chalcopyrite in 25 days. The bacterial and archaeal diversities during adaptation were analyzed by denaturing gradient gel electrophoresis and constructing clone libraries of 16S rRNA gene. The results show that the culture was consisted mainly of four species before adapting to a pulp density of 4%, including Leptospirillum ferriphilum, Acidithiobacillus caldus, Sulfobacillus acidophilus and Ferroplasma thermophilum. However, L. ferriphilum could not be detected when pulp density was greater than 4%. Real-time quantitative PCR was employed to monitor the microbial dynamics during bioleaching at a pulp density of 20%. The results show that A. caldus was the predominant species in the initial stage, while S. acidophilus instead of A. caldus became the predominant species in the middle stage. F. thermophilum accounted for the greatest proportion in the final stage.
    Applied and Environmental Microbiology 11/2013; DOI:10.1128/AEM.02907-13 · 3.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The shift of microbial community under the adjustment of different pH was analyzed by denaturing gradient gel electrophoresis (DGGE). The results indicated, at initial pH 1.0, 2.0 and 3.0, the copper extraction in 22days amounted to 84.6%, 88.2% and 77.5%, respectively; however, when the initial pH was 2.0, processing pH was adjusted to 1.0 and 3.0 on day 16, the copper extraction in 32days was 85% and 62.6%, respectively. DGGE analysis showed Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans and Ferroplasma thermophilum existed in bioleaching systems. At initial pH 1.0 and 3.0, S. thermosulfidooxidans and A. caldus were main microorganisms. While at initial pH 2.0, L. ferriphilum, A. caldus and S. thermosulfidooxidans were always detected. At processing pH 1.0 and 3.0, the adjustment of pH greatly inhibited the growth of L. ferriphilum; it was also found microbial community would recover gradually only if pH stimulation did not fatally affect microorganisms.
    Bioresource Technology 04/2014; 162C:300-307. DOI:10.1016/j.biortech.2014.03.163 · 5.04 Impact Factor