Acidithiobacillus

A.ci.di.thi.o.ba.cil'lus. L. masc. adj. acidus sour, tart; Gr. neut. n. theîon sulfur, brimstone (transliterated to L. neut. n. thium); L. masc. n. bacillus a short rod, a short wand; N.L. masc. n. Acidithiobacillus acid‐loving sulfur rodlet. Proteobacteria / Acidithiobacillia / Acidithiobacillales / Acidithiobacillaceae / Acidithiobacillus Cells are short, motile rods with a single polar flagellum. Some strains have an obvious glycocalyx. Gram‐stain‐negative. Endospores, exospores, and cysts are not produced. Obligate chemolithoautotrophs, with electron donors including reduced inorganic sulfur species such as thiosulfate, tetrathionate, and elementary sulfur (viz. α‐S8 and μ‐S∞). Some species can also use molecular hydrogen, ferrous iron, or metal sulfides such as pyrite (FeS2) as electron donors. Some species are diazotrophic. Heterotrophy, methylotrophy, and the so‐called C1 autotrophy are not observed. Carbon assimilated from CO2 via the transaldolase variant of the Calvin–Benson–Bassham cycle. Carboxysomes are used for CO2 concentration. Obligately respiratory, with molecular oxygen, ferric iron, or elementary sulfur as terminal electron acceptors, varying by species. Most strains grow in the range of 20–37°C, though some have a narrower range, and one species is thermophilic. Optimal growth from pH 2.0 to 5.8 and an overall range of pH −0.6 to 6.0. The major respiratory quinone is ubiquinone‐8 (UQ‐8), and traces of ubiquinone‐9 (UQ‐9), ubiquinone‐7 (UQ‐7), and menaquinones (MK) are found in some species. The dominant fatty acids are palmitic acid (C16:0), vaccenic acid (C18:1), cis‐11‐cyclopropyl‐nonadecanoic acid (C19:0 cyclo ω8c), palmitoleic acid (C16:1), myristic acid (C14:0), and lauric acid (C12:0). The dominant polar lipids are cardiolipin, aminolipids, phospholipid, phosphatidylglycerol, and phosphatidylethanolamine. The G + C fraction of genomic DNA is around 52.0–63.9 mol%. Form IAc (carboxysomal) and Form II (cytoplasmic) d‐ribulose 1,5‐bisphosphate carboxylase/oxygenase are used, as are forms bo 3 and bd‐I ubiquinol oxidases and, in the iron‐oxidizing species, the aa 3‐type cytochrome c oxidase. A description of Acidithiobacillus concretivorus comb. nov. is also given. DNA G + C content (mol%): 52.0–63.9. Type species: Acidithiobacillus thiooxidans Kelly and Wood 2000VP (Thiobacillus thiooxidans Waksman and Joffe 1922AL)

Phylogenetic assessment of culture collection strains of Thiobacillus thioparus, and definitive 16S rRNA gene sequences for T. thioparus, T. denitrificans, and Halothiobacillus neapolitanus

The 16S rRNA gene sequences of 12 strains of Thiobacillus thioparus held by different culture collections have been compared. A definitive sequence for the reference type strain (Starkey; ATCC 8158T) was obtained. The sequences for four examples of the Starkey type strain were essentially identical, confirming their sustained identity after passage through different laboratories. One strain (NCIMB 8454) was reassigned as a strain of Halothiobacillus neapolitanus, and a second (NCIMB 8349) was a species of Thermithiobacillus. These two strains have been renamed in their catalog by the National Collection of Industrial and Marine Bacteria. The 16S rRNA gene sequence of the type strain of Halothiobacillus neapolitanus (NCIMB 8539T) was determined and used to confirm the identity of other culture collection strains of this species. The reference sequences for the type strains of Thiobacillus thioparus and Halothiobacillus neapolitanus have been added to the online List of Prokaryotic Names with Standing in Nomenclature. Comparison of the 16S rRNA gene sequences available for strains of Thiobacillus denitrificans indicated that the sequence for the type strain (NCIMB 9548T) should always be used as the reference sequence for new and existing isolates

Thiobacillus plumbophilus spec. nov., a novel galena and hydrogen oxidizer

From an uranium mine three strains of rodshaped, mesophilic, chemolithoautotrophic bacteria were isolated. They grow by oxidation of H2S, galena (PbS) and H2. Anglesite (PbSO4) is formed from galena. No ferrous iron is oxidized by the isolates. They grow between pH 4 and 6.5 at temperatures of about 9 to 41°C (optimum around 27°C). The G+C content of the DNA is around 66 mol %. Based on their ability to oxidize sulfur compounds, the new organisms belong to the genus Thiobacillus. No significant homology with Thiobacillus ferrooxidans and Thiobacillus cuprinus was detected by DNA-DNA hybridization. Therefore the new isolates represent a new species within the genus Thiobacillus. Based on the unusual growth on galena, we name the new species Thiobacillus plumbophilus (type strain Gro 7; DSM 6690)