Halothiobacillus kellyi sp. nov., a mesophilic, obligately chemolithoautotrophic, sulfur-oxidizing bacterium isolated from a shallow-water hydrothermal vent in the Aegean Sea, and emended description of the genus Halothiobacillus.

Abstract

Wood 2000). Strain Milos-BII1T represents a new species of this genus, named Halothiobacillus kellyi. Cells were Gram-negative rods and highly motile. The organism was obligately autotrophic and strictly aerobic. Nitrate was not used as electron acceptor. Chemolithoautotrophic growth was observed with thiosulfate, tetrathionate, sulfur and sulfide. Growth was observed between pH values of 35 and 85, with an optimum at pH 65. The temperature limits for growth were 35 and 49 SC, with an optimum between 37 and 42 SC. Growth occurred between 0 and 2 M NaCl, with an optimum NaCl concentration between 400 and 500 mM. The mean maximum specific growth rate on thiosulfate was 045 h N1 .

Thiovirga sulfuroxydans gen. nov., sp. nov., a chemolithoautotrophic sulfur-oxidizing bacterium isolated from a microaerobic waste-water biofilm

“…In contrast to members of the genus Halothiobacillus, strain SO07 T did not require NaCl for growth and the growth of this strain was completely inhibited at NaCl concentrations greater than 180 mM (Table 1). In fact, all Halothiobacillus species have high NaCl tolerances (more than 860 mM NaCl and up to 4000 mM) and their optimal NaCl concentrations for growth are relatively high (more than 400 mM NaCl) (Kelly & Wood, 2000;Sievert et al, 2000). These distinctive characteristics of strain SO07 T allow it to be differentiated Table 1.…”

“…All species were obligately chemolithoautotrophic, mesophilic, neutrophilic motile rods and oxidized thiosulfate, sulfur and sulfide. Data from Kelly & Wood (2000), Sievert et al (2000) and Brinkhoff et al (1999a, b The type strain is SO07 T (=JCM 12417 T =ATCC BAA-1033 T ). The DNA G+C content of the type strain is 47?1 mol%.…”

Isolation, Characterization, and In Situ Detection of a Novel Chemolithoautotrophic Sulfur-Oxidizing Bacterium in Wastewater Biofilms Growing under Microaerophilic Conditions

“…The 16S rRNA gene sequences of strain SO07 and previously identified Halothiobacillus species were, however, 89% similar at most. The most notable difference between the genus Halothiobacillus and strain SO07 is that strain SO07 cannot grow under high NaCl concentrations (no growth above 150 mM NaCl), while the genus Halothiobacillus requires 400 to 1,000 mM NaCl and can tolerate up to 4,000 mM NaCl (22,36). Therefore, it seems inappropriate to class strain SO07 as a species of Halothiobacillus.…”

“…The diversity and in situ ecophysiology of sulfate-reducing bacteria in the wastewater biofilms have been intensively investigated by a 16S rRNA gene approach and microelectrodes (16,17,32,33,35), while the diversity and ecological importance of sulfur-oxidizing bacteria involved in the sulfur cycle are still largely unknown. Recently, novel sulfur-oxidizing bacteria belonging to the ␥ and ε subclasses of the Proteobacteria have been discovered and isolated from various habitats, e.g., marine mud (7,8), oil field waters (12,23), and a hydrothermal vent system (36). Moreover, sulfur-oxidizing bacteria originally classified as Thiobacillus species were reclassified into the ␣, ␤, and ␥ subclasses of the Proteobacteria based on their phylogenetic relatedness and their physiological similarities (14,19,21,22,29).…”

Thioprofundum hispidum sp. nov., an obligately chemolithoautotrophic sulfur-oxidizing gammaproteobacterium isolated from the hydrothermal field on Suiyo Seamount, and proposal of Thioalkalispiraceae fam. nov. in the order Chromatiales

“…In addition, several environmental strains belonging to the class Gammaproteobacteria have been retrieved from hydrothermal fields, cold-seep sediments and marine crusts (Arakawa et al, 2006;Inagaki et al, 2004;Li et al, 1999;Santelli et al, 2008), some of which have been suggested as having sulfur-oxidizing metabolism (Hirayama et al, 2007;Sunamura et al, 2004). As for cultivated Gammaproteobacteria, some species of the genera Halothiobacillus and Thiomicrospira have been isolated from these environments (Brinkhoff et al, 1999;Sievert et al, 2000;Takai et al, 2004).…”