Spirochaeta perfilievii sp. nov., an oxygen-tolerant, sulfide-oxidizing, sulfur- and thiosulfate-reducing spirochaete isolated from a saline spring

Abstract

A novel strain of fermenting, aerotolerant, chemo-organoheterotrophic spirochaete designated P T was isolated from a sulfur 'Thiodendron' mat in a saline spring at the Staraya Russa resort (Novgorod Region, Russia). Cells of strain P T exhibited a helical shape. The spirochaete required sulfide in the growth medium and was able to oxidize it non-enzymically to elemental sulfur via the interaction of H 2 O 2 with sulfide and deposit it in the periplasmic space. Growth occurred at 4-32 6C (optimum at 28-30 6C), pH 6.0-8.5 (optimum pH 7.0-7.5), and in 0.1-1 M NaCl (optimum 0.35 M). The isolate used several sugars and polysaccharides as carbon or energy sources but did not use peptides, amino acids, organic acids or alcohols. The products of glucose fermentation were formate, acetate, ethanol, pyruvate, CO 2 and H 2 . The genomic DNA G+C content was 41.7 mol%. 16S rRNA gene sequence analysis showed that strain P T fell within a group of species in the genus Spirochaeta, including Spirochaeta litoralis, S. isovalerica and S. cellobiosiphila, with which it shared less then 89 % sequence similarity. On the basis of its morphology, physiology and other phenotypic properties, as well as its phylogenetic position, the new isolate is considered to represent a novel species of the genus Spirochaeta, for which the name Spirochaeta perfilievii sp. nov. is proposed. The type strain is P T (5DSM 19205 T 5VKM

Identity of major sulfur-cycle prokaryotes in freshwater lake ecosystems revealed by a comprehensive phylogenetic study of the dissimilatory adenylylsulfate reductase

“…The aprBA gene locus was identified in the draft genome of Spirochaeta odontotermitis JC202, as the first case in the phylum Spirochaetes . Although spirochetes have been found in sulfidic environments such as the enrichment cultures of sulfate reducers and sulfur ‘Thiodendron’ mat17, their genes involved in dissimilatory sulfur metabolism have not been identified. The genome of Spirochaeta odontotermitis JC202 also encodes other key enzymes involved in dissimilatory sulfate reduction (Supplementary Fig.…”

Destruction of spirochete Borrelia burgdorferi round-body propagules (RBs) by the antibiotic Tigecycline

“…This morphological transition from periplasmically flagellated, helically motile spirochetes to RBs develops naturally in mixed and pure cultures under conditions that tend to limit growth, and is reversible (23). Many spirochetes under inhibitory changes in oxygen or sulfide concentration fail to form cross walls and elongate into unrecognizable filaments (7). Both the filamentous and round body forms of spirochetes are fully viable.…”

“…Transition from one growth medium to a second of different viscosity or temperature stimulates the formation of RBs. Starvation, threat of desiccation, exposure to oxygen gas, total anoxia and/or sulfide may induce RB formation (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). RBs revert to the active helical swimmers when favorable conditions that support growth return (3)(4)(5).…”

Calcium dynamics in microbialite‐forming exopolymer‐rich mats on the atoll of Kiritimati, Republic of Kiribati, Central Pacific

“…(<28%). Sulfide oxidizing members of the latter group were recently identified (Dubinina et al, 2011).…”