Thermosinus carboxydivorans gen. nov., sp. nov., a new anaerobic, thermophilic, carbon-monoxide-oxidizing, hydrogenogenic bacterium from a hot pool of Yellowstone National Park

Abstract

A new anaerobic, thermophilic, facultatively carboxydotrophic bacterium, strain Nor1 T , was isolated from a hot spring at Norris Basin, Yellowstone National Park. Cells of strain Nor1 T were curved motile rods with a length of 2?6-3 mm, a width of about 0?5 mm and lateral flagellation. The cell wall structure was of the Gram-negative type. Strain Nor1 T was thermophilic (temperature range for growth was 40-68 6C, with an optimum at 60 6C) and neutrophilic (pH range for growth was 6?5-7?6, with an optimum at 6?8-7?0). It grew chemolithotrophically on CO (generation time, 1?15 h), producing equimolar quantities of H 2 and CO 2 according to the equation CO+H 2 ORCO 2 +H 2 . During growth on CO in the presence of ferric citrate or amorphous ferric iron oxide, strain Nor1 T reduced ferric iron but produced H 2 and CO 2 at a ratio close to 1 : 1, and growth stimulation was slight. Growth on CO in the presence of sodium selenite was accompanied by precipitation of elemental selenium. Elemental sulfur, thiosulfate, sulfate and nitrate did not stimulate growth of strain Nor1 T on CO and none of these chemicals was reduced. Strain Nor1 T was able to grow on glucose, sucrose, lactose, arabinose, maltose, fructose, xylose and pyruvate, but not on cellobiose, galactose, peptone, yeast extract, lactate, acetate, formate, ethanol, methanol or sodium citrate. During glucose fermentation, acetate, H 2 and CO 2 were produced. Thiosulfate was found to enhance the growth rate and cell yield of strain Nor1 T when it was grown on glucose, sucrose or lactose; in this case, acetate, H 2 S and CO 2 were produced. In the presence of thiosulfate or ferric iron, strain Nor1 T was also able to grow on yeast extract. Lactate, acetate, formate and H 2 were not utilized either in the absence or in the presence of ferric iron, thiosulfate, sulfate, sulfite, elemental sulfur or nitrate. Growth was completely inhibited by penicillin, ampicillin, streptomycin, kanamycin and neomycin. The DNA G+C content of the strain was 51?7±1 mol%. Analysis of the 16S rRNA gene sequence revealed that strain Nor1 T belongs to the Bacillus-Clostridium phylum of the Gram-positive bacteria. On the basis of the studied phenotypic and phylogenetic features, we propose that strain Nor1 T be assigned to a new genus, Thermosinus gen. nov. The type species is Thermosinus carboxydivorans sp. nov. (type strain, Nor1 T =DSM 14886 T =VKM B-2281 T ).

Complete Genome Sequence of Geobacillus strain Y4.1MC1, a Novel CO-Utilizing Geobacillus thermoglucosidasius Strain Isolated from Bath Hot Spring in Yellowstone National Park

“…Researchers have isolated obligate anaerobic thermophiles from a number of environments including the first and most-studied acetogen, Moorella thermoacetica (formerly Clostridium thermocellum) whose genome was sequenced and analyzed [6]. Since then, other thermophilic CO oxidizers that utilize the WoodLjungdahl pathway have been isolated including Thermosinus carboxydivorans [7], Thermolithobacter carboxydivorans [8], and many from Yellowstone hot springs. All the isolated thermophiles with the Wood-Ljungdahl pathway are strict anaerobes, and no aerobic or facultative anaerobic thermophiles have been isolated.…”

CO Metabolism in the Thermophilic Acetogen Thermoanaerobacter kivui

“…However, some organisms can use carbon monoxide as an electron and carbon source (1,2). These organisms are aerobic carboxydotrophic bacteria such as Oligotropha carboxydovorans (3), phototrophic purple sulfur bacteria such as Rhodospirillum rubrum (4), hydrogenogenic bacteria and archaea such as Thermosinus carboxydivorans (5) or Thermococcus sp. strain AM4 (6), or some organisms that employ the Wood-Ljungdahl pathway (WLP), such as methanogens (7)(8)(9) or acetogens (10)(11)(12)(13).…”

Hitherto Unknown [Fe-Fe]-Hydrogenase Gene Diversity in Anaerobes and Anoxic Enrichments from a Moderately Acidic Fen

“…2) and were only distantly related to those previously amplified from a saline microbial mat or domestic sewage (data not shown) (3,34). Hydrogenases were grouped into five distinct clusters and were affiliated with hydrogenases of species from the cellulolytic fermenter Clostridium thermocellum (68 to 69% amino acid sequence identity to enrich_clones 2 and 7 [36]), the sulfate and metal reducer Desulfotomaculum reducens (71% identity to enrich_clone 6 [27]), the primary fermenter and carboxydotroph Thermosinus carboxydivorans (70% identity to enrich_clone 8 [26] HydH1f TTIACITSITGYWSYCCIGSHTGG This study 523 192 85 71 28 3 1 0 HydH3r CAICCIYMIGGRCAISNCAT This study 1126 64 138 16 26 8 0 0 hydF1 GCCGACCTKACMATMATGGA 34 445 8 8 19 29 43 43 46 hydR1 ATRCARCCRCCSGGRCAGGCCAT 34 1126 32 11 20 39 40 32 46 FeFe-272F GCHGAYMTBACHATWATGGARGA 3 445 432 39 47 52 21 10 19 FeFe-427R GCNGCYTCCATDACDCCDCCNGT 3 895 864 82 48 20 12 7 19 a I, inosine. IUPAC nomenclature was used for mixed bases (5).…”