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.
"Ferroplasma spp. are iron-oxidizing acidophilic archaea and appear to be a very diverse group of microorganisms (Dopson et al. 2004; Golyshina et al. 2000; Hawkes et al. 2006). F. thermophilum L1 is a mixotrophic and moderate thermophilic archaeon. "
[Show abstract][Hide abstract] ABSTRACT: To compare oxidative dissolution rates of chalcopyrite by different consortia of moderately thermophilic acidophiles, various defined mixed cultures of three bacteria Acidithiobacillus caldus s2, Leptospirillum ferriphilum YSK, and Sulfobacillus sp. LN and one archaeon Ferroplasma thermophilum L1 were studied in batch shake flask cultures incubated at 45 degrees C. Chalcopyrite dissolution was determined by measuring variations of soluble copper, ferric iron, and pH. Microbial population dynamics involved in bioleaching process were monitored using real-time quantitative polymerase chain reaction (PCR) technology. The complex consortia containing both chemoautotrophic (L. ferriphilum and At. caldus) and chemomixotrophic (Sulfobacillus LN and F. thermophilum) moderate thermophiles were found to be the most efficient in all of those tested. Mutualistic interactions between physiologically distinct moderately thermophilic acidophiles, involving transformations of iron and sulfur and transfer of organic compound, were considered to play a critical role in promoting chalcopyrite dissolution. The real-time PCR assay was reliable to analyze population dynamics of moderate thermophiles in bioleaching systems, and the analysis results were consistent with physiological characteristics of these strains.
[Show abstract][Hide abstract] ABSTRACT: The main representatives of acidophilic chemolithotrophs oxidizing sulfide minerals, ferrous iron, elemental sulfur, and reduced sulfur compounds and forming microbial communities in the natural and technogenic ecosystems with low pH values and high concentrations of heavy metal ions are listed. The species and strain diversity of the communities and environmental factors affecting their composition (temperature, pH value, energy substrate, mineralogical composition of sulfide ore concentrates, the presence of organic substances, and level of aeration) are analyzed. Involvement of mobile genetic elements (IS elements and plasmids) in the structural changes of the chromosomal DNA in the course of switching microbial metabolism to the oxidation of new energy substrates or under increased concentrations of metal ions is shown to be a probable mechanism responsible for the intraspecific genetic heterogeneity of the populations. Importance of determination of the dominant strains of different microbial species in the communities and of their physiological peculiarities for stabilization, optimization, and enhancement of efficiency of biotechnological processes for sulfide mineral oxidation is stressed.
[Show abstract][Hide abstract] ABSTRACT: Based on a new selective isolation strategy that mimicked physiological characteristics of leptospirilla, such as pH, temperature
and its less sensitivity to the high ferric-ferrous iron ratio, a bacterial strain, called strain YSK, was isolated from an
extreme acid mine drainage (AMD) site. Cells were Gram-negative, small curved rods measuring 0.27–0.52 by 0.81–3.17 μm. The
cell shape suggested that strain YSK was likely a strain ofLeptospirillum ferrooxidans. However, based on the 16S rDNA sequence analysis, strain YSK possessed 100% sequence similarity with that of the typicalLeptospirillum ferriphilum strain Fairview; furthermore, the G+C content, the size of the 16S–23S rRNA gene spacer regions and the ability to grow at
45°C further indicated that strain YSK belonged to the speciesLeptospirillum ferriphilum.
Annals of Microbiology 06/2007; 57(2):171-176. DOI:10.1007/BF03175203 · 0.99 Impact Factor
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