Sideroxyarcus emersonii gen. nov. sp. nov., a neutrophilic, microaerobic iron- and thiosulfate-oxidizing bacterium isolated from iron-rich wetland sediment
Shingo Kato, Takashi Itoh, Takao Iino, Moriya Ohkuma
Abstract
A neutrophilic iron-oxidizing bacterium, strain MIZ01 T , which was previously isolated from a wetland in Ibaraki, Japan, was taxonomically characterized in detail. Strain MIZ01 T was a motile, curved-rod shaped, Gram-stain-negative bacterium. It was able to grow at 10–40 °C (optimally at 30–35 °C) and at pH 5.5–7.0 (optimally at pH 6.0). It grew microaerobically and chemolithoautotrophically using thiosulfate, in addition to ferrous iron, as the sole electron donor. Major cellular fatty acids of strain MIZ01 T were C 16 : 1 ω 7 c /C 16 : 1 ω 6 c and C 16 : 0 . The complete genome sequence (2.74 Mbp) was determined, showing that its DNA G+C content was 60.0 mol%. Phylogenetic analyses indicated that strain MIZ01 T belonged to the family Gallionellaceae , class Betaproteobacteria , and was closely related to an isolate tentatively named ‘ Sideroxydans lithotrophicus ’ ES-1 (98.2 % of 16S rRNA gene sequence similarity). Based on its phenotypic and phylogenetic characteristics, we conclude that strain MIZ01 T represents a new genus and species in the family Gallionellaceae for which we propose the name Sideroxyarcus emersonii gen. nov., sp. nov. The type strain is strain MIZ01 T (=JCM 39089 T =DSM 111897 T ).