Acidocella aromatica sp. nov.: an acidophilic heterotrophic alphaproteobacterium with unusual phenotypic traits
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Three obligately heterotrophic bacterial isolates were identified as strains of a proposed novel species of extremely acidophilic, mesophilic Alphaproteobacteria, Acidocella aromatica. They utilized a restricted range of organic substrates, which included fructose (but none of the other monosaccharides tested), acetate and several aromatic compounds (benzoate, benzyl alcohol and phenol). No growth was obtained on complex organic substrates, such as yeast extract and tryptone. Tolerance of the proposed type strain of the species (PFBC) to acetic acid was much greater than that typically reported for acidophiles. The bacteria grew aerobically, and catalyzed the dissimilatory reductive dissolution of the ferric iron mineral schwertmannite under both micro-aerobic and anaerobic conditions. Strain PFBC did not grow anaerobically via ferric iron respiration, though it has been reported to grow in co-culture with acid-tolerant sulfidogenic bacteria under strictly anoxic conditions. Tolerance of strains of Acidocella aromatica to nickel were about two orders of magnitude greater than those of other Acidocella spp., though similar levels of tolerance to other metals tested was observed. The use of this novel acidophile in solid media designed to promote the isolation and growth of other (aerobic and anaerobic) acidophilic heterotrophs is discussed.
KeywordsAcidophilic heterotrophs Acidocella Aromatic compounds Acetic acid
RMJ is grateful to the European Union and Nelsons UK for the provision of a research studentship under the Knowledge Economy Skills Scholarship (KESS) scheme. We are grateful to Dr. Olga Golyshina (Bangor University) for carrying out the G + C analysis of genomic DNA.
- Hallberg KB, Kolmert ÅK, Johnson DB, Williams PA (1999) A novel metabolic phenotype among acidophilic bacteria: aromatic degradation and the potential use of these organisms for the treatment of wastewater containing organic and inorganic pollutants. In: Amils R, Ballester A (eds) Biohydrometallurgy and the environment toward the mining of the 21st century, Part A. Elsevier, Amsterdam, pp 719–728Google Scholar
- Kermer R, Hedrich S, Taubert M, Baumann S, Schlömann M, von Bergen M, Seifert J (2012) Elucidation of carbon transfer in a mixed culture of Acidiphilium cryptum and Acidithiobacillus ferrooxidans using protein-based stable isotope probing. J Integr Omics 2:37–45Google Scholar
- Kimoto K, Aizawa T, Urai M, Ve NB, Suzuki K, Nakajima M, Sunairi M (2010) Acidocella aluminiidurans sp. nov., an aluminium tolerant bacterium isolated from Panicum repens grown in a highly acidic swamp in actual acid sulfate soil area of Vietnam. Int J Syst Evol Microbiol 60:764–768PubMedCrossRefGoogle Scholar
- Meulenberg R, Pronk JT, Hazeu W, Bos P, Kuenen JG (1992) Oxidation of inorganic sulfur compounds by intact cells of Thiobacillus acidophilus. Arch Microbiol 157:161–168Google Scholar
- Okibe N, Gericke M, Hallberg KB, Johnson DB (2003) Enumeration and characterization of acidophilic microorganisms isolated from a pilot plant stirred tank bioleaching operation. Appl Environ Microbiol 69:1936–1943Google Scholar
- Servin-Garcidueňas LE, Garrett RA, Amils R, Martinez-Romero E (2013) Genome sequence of the acidophilic bacterium Acidocella sp. strain MX-AZ02. Genom Announ 1:e00041–e000412Google Scholar
- Tamaoka J, Komagata K (1984) Determination of DNA base composition by reversed-phase high-performance liquid chromatography. FEMS Microbiol Lett 25:25–128Google Scholar