Biomedical subjects

T P Tourova

Publications and source records attributed to T P Tourova.

At least 19 recordsLinked to original sources

PubMed2006

Tepidimicrobium ferriphilum gen. nov., sp. nov., a novel moderately thermophilic, Fe(III)-reducing bacterium of the order Clostridiales.

A moderately thermophilic, anaerobic bacterium (strain SB91T) was isolated from a freshwater hot spring at Barguzin Valley, Buryatiya, Russia. Cells of strain SB91T were straight to slightly curved rods, 0.5-0.6 microm in diameter and 3.0-7.0 mum in length. Formation of endospores was not observed. The temperature range for growth was 26-62 degrees C, with an optimum at 50 degrees C. The pH range for growth was 5.5-9.5, with an optimum at pH 7.5-8.0. The substrates utilized by strain SB91T in the presence of 9,10-anthraquinone 2,6-disulfonate included peptone, tryptone, Casamino acids, yeast extract, beef extract, casein hydrolysate, alanine plus glycine, alanine plus proline, L-valine and n-propanol. Carbohydrates were not utilized. Strain SB91T reduced amorphous Fe(III) oxide, Fe(III) citrate, Fe(III) EDTA or Fe(III) nitrilotriacetate with peptone, L-valine or n-propanol as an electron donor. Strain SB91T reduced 9,10-anthraquinone 2,6-disulfonate, thiosulfate, elemental sulfur, fumarate and selenite. Strain SB91T survived after exposure to gamma-radiation at a dose of 5.4 kGy. The G+C content of the DNA of strain SB91T was 33 mol%. Analysis of the 16S rRNA gene sequence revealed that the isolated organism belonged to cluster XII of the clostridia. On the basis of its physiological properties and the results of phylogenetic analyses, it is proposed that strain SB91T represents the sole species of a novel genus, Tepidimicrobium; the name Tepidimicrobium ferriphilum gen. nov., sp. nov. is proposed, with strain SB91T (=DSM 16624T=VKM B-2348T) as the type strain.

Bacteria, Anaerobic↗

PubMed2006

Extremely halophilic denitrifying bacteria from hypersaline inland lakes, Halovibrio denitrificans sp. nov. and Halospina denitrificans gen. nov., sp. nov., and evidence that the genus name Halovibrio Fendrich 1989 with the type species Halovibrio variabilis should be associated with DSM 3050.

Anaerobic enrichments with acetate as electron donor and nitrate as electron acceptor at 4 M NaCl from inland, hypersaline lake sediments from Central Asia resulted in the isolation of several extremely halophilic bacteria that comprised two subgroups, most with vibrio-shaped cells and a single strain with rod-shaped cells. Members of both subgroups were extremely halophilic, with growth occurring in 2-5 M NaCl with an optimum at 2-3 M. 16S rRNA gene sequence analysis showed a close affiliation of the new isolates with Pseudomonas halophila DSM 3050 in the Gammaproteobacteria. However, phenotypic comparison of the denitrifying halophiles with the original description of P. halophila demonstrated that they were more similar to another bacterium isolated from the same source at the same time, the extremely halophilic Halovibrio variabilis, which has since been reclassified as Halomonas variabilis (DSM 3051). Direct cross-comparison showed that the characteristics of these two halophilic bacteria do not correspond with the original descriptions associated with these names and DSM numbers. While it is desirable that this problem be solved, in connection with the present investigations, this is a matter that can only be solved by a Request for an Opinion. On the basis of the phenotypic and genetic comparison of these isolates, it is proposed that the new denitrifying vibrio-shaped isolates represent a novel species, Halovibrio denitrificans sp. nov. (type strain HGD 3T=DSM 15503T=UNIQEM U232T) and that the rod-shaped isolate represents a novel genus and species, Halospina denitrificans gen. nov., sp. nov. (type strain HGD 1-3T=DSM 15505T=UNIQEM U233T).

Bacterial Typing Techniques↗

PubMed2005

Citreicella thiooxidans gen. nov., sp. nov., a novel lithoheterotrophic sulfur-oxidizing bacterium from the Black Sea.

Four strains of obligately heterotrophic bacteria isolated from the oxygen-sulfide interface of the Black Sea are characterized. The bacteria are aerobic, Gram-negative, with lemon-like, nonmotile cells. Bacteriochlorophyll a is not detected. They are mesophilic and neutrophilic with a temperature range of 8-35 degrees C (optimum 25) and pH range of 6.5-8.5 (optimum 7.8). Their growth is NaCl dependent within a range of 5 and 60 (optimum 20) g l(-1). They are able to oxidize thiosulfate, sulfide and elemental sulfur to sulfate and to use metabolic energy from these reactions (lithoheterotrophy). According to the level of DNA reassociation of more than 40%, all isolates represent a single generic group. The G+C content of the DNA was in the range of 67.5-69.2mol%. According to phylogenetic analysis, the new isolates form a separate branch in the alpha-3 subdivision of the Proteobacteria together with two undescribed marine bacterial strains. On the basis of phenotypical and genomic properties, the new isolates are described as a new genus and species Citreicella thiooxidans gen. nov., sp. nov. The type strain is CHLG 1T ( = DSM 10146, UNIQEM U 228).

Alphaproteobacteria↗

PubMed2005

Desulfurococcus fermentans sp. nov., a novel hyperthermophilic archaeon from a Kamchatka hot spring, and emended description of the genus Desulfurococcus.

An obligately anaerobic, hyperthermophilic, organoheterotrophic archaeon, strain Z-1312(T), was isolated from a freshwater hot spring of the Uzon caldera (Kamchatka Peninsula, Russia). The cells were regular cocci, 1-4 microm in diameter, with one long flagellum. The cell envelope was composed of a globular layer attached to the cytoplasmic membrane. The temperature range for growth was 63-89 degrees C, with an optimum between 80 and 82 degrees C. The pH range for growth at 80 degrees C was 4.8-6.8, with an optimum at pH 6.0. Strain Z-1312(T) grew by hydrolysis and/or fermentation of a wide range of polymeric and monomeric substrates, including agarose, amygdalin, arabinose, arbutin, casein hydrolysate, cellulose (filter paper, microcrystalline cellulose, carboxymethyl cellulose), dextran, dulcitol, fructose, lactose, laminarin, lichenan, maltose, pectin, peptone, ribose, starch and sucrose. No growth was detected on glucose, xylose, mannitol or sorbitol. Growth products when sucrose or starch were used as the substrate were acetate, H(2) and CO(2). Elemental sulfur, thiosulfate and nitrate added as potential electron acceptors for anaerobic respiration did not stimulate growth when tested with starch as the substrate. H(2) at 100 % in the gas phase did not inhibit growth on starch or peptone. The G+C content of the DNA was 42.5 mol%. 16S rRNA gene sequence analysis placed the isolated strain Z-1312(T) as a member of the genus Desulfurococcus, where it represented a novel species, for which the name Desulfurococcus fermentans sp. nov. (type strain Z-1312(T) = DSM 16532 (T) = VKM V-2316(T)) is proposed.

Acetic Acid↗

PubMed2003

Tepidibacter thalassicus gen. nov., sp. nov., a novel moderately thermophilic, anaerobic, fermentative bacterium from a deep-sea hydrothermal vent.

A moderately thermophilic, anaerobic, endospore-forming bacterium (strain SC 562T) was isolated from a hydrothermal vent chimney located at 13 degrees N on the East-Pacific Rise at a depth of 2650 m. Cells of strain SC 562T were straight to slightly curved rods, which were 0.7-0.9 microm in diameter and 3.5-6.0 microm in length with peritrichous flagella. Strain SC 562T formed round, refractile endospores in terminally swollen sporangia. The temperature range for growth was 33-60 degrees C, with an optimum at 50 degrees C. The pH range for growth was 4.8-8.5, with an optimum at pH 6.5-6.8. Growth of strain SC 562T was observed at NaCl concentrations ranging from 1.5 to 6% (w/v). The substrates utilized by strain SC 562T included casein, peptone, albumin, yeast extract, beef extract, alanine plus proline and starch. Glucose, maltose, pyruvate, valine and arginine each slightly stimulated growth in the presence of yeast extract. The products of glucose fermentation were ethanol, acetate, H2 and CO2. Strain SC 562T reduced elemental sulfur to hydrogen sulfide. The G + C content of the DNA of strain SC 562T was 24 mol%. 16S rDNA sequence analysis revealed that the isolated organism belonged to cluster XI of the Clostridium subphylum. On the basis of its physiological properties and phylogenetic analyses, it is proposed that strain SC 562T represents the sole species of a novel genus, Tepidibacter; the name Tepidibacter thalassicus is proposed for strain SC 562T (=DSM 15285T=UNIQEM 215T).

Base Composition↗

PubMed2002

Thermovenabulum ferriorganovorum gen. nov., sp. nov., a novel thermophilic, anaerobic, endospore-forming bacterium.

A thermophilic, anaerobic, spore-forming bacterium (strain Z-9801T) was isolated from a terrestrial hydrothermal source in the Uzon caldera on the Kamchatka peninsula. Cells of strain Z-9801T were straight, sometimes branched rods, 0.5-0.6 microm in diameter and 1.5-7.0 microm in length, with peritrichous flagella. The temperature range for growth was 45-76 degrees C, with an optimum at 63-65 degrees C. The pH range for growth was 4.8-8.2, with an optimum at 6.7-6.9. The substrates utilized by strain Z-9801T included peptone, yeast extract, beef extract, Casamino acids, starch, pyruvate, melibiose, sucrose, fructose, maltose, xylose and ribose. The fermentation products from melibiose were ethanol, acetate, H2 and CO2. Strain Z-9801T used H2 in the presence of Fe(III) and an organic electron donor. Strain Z-9801T reduced Fe(III), Mn(IV), nitrate, fumarate, sulfite, thiosulfate, elemental sulfur and 9,10-anthraquinone 2,6-disulfonate. The G+C content of strain Z-9801T DNA was 36 mol%. 16S rDNA sequence analysis revealed that the isolated organism forms a separate branch within the Bacillus/Clostridium group. On the basis of physiological properties and phylogenetic analysis, it is proposed that strain Z-9801T (= DSM 14006T = UNIQEM 210T) should be assigned to a novel species of a new genus, Thermovenabulum ferriorganovorum gen. nov., sp. nov.

Bacteria, Anaerobic↗

PubMed2002

Carboxydocella thermautotrophica gen. nov., sp. nov., a novel anaerobic, CO-utilizing thermophile from a Kamchatkan hot spring.

A novel anaerobic, thermophilic, CO-utilizing bacterium, strain 41(T), was isolated from a terrestrial hot vent on the Kamchatka Peninsula. Strain 41(T) was found to be a Gram-positive bacterium, its cells being short, straight, motile rods. Chains of three to five cells were often observed. The isolate grew only chemolithoautotrophically on CO, producing equimolar quantities of H2 and CO2 (according to the equation CO+H2O --> CO2+H2). Growth was observed in the temperature range 40-68 degrees C, with an optimum at 58 degrees C, and in the pH range 6.5-7.6, with an optimum at pH 7.0. The generation time under optimal conditions for chemolithotrophic growth was 1.1 h. The DNA G+C content was 46 +/- 1 mol%. Growth was completely inhibited by penicillin, ampicillin, streptomycin, kanamycin and neomycin. On the basis of the phenotypic and phylogenetic features, it is proposed that this isolate represents a new genus and species, Carboxydocella thermautotrophica gen. nov., sp. nov. (type strain 41(T) = DSM 12356(T) = VKM B-2282(T)).

Bacteria, Anaerobic↗

PubMed2001

Methanosarcina lacustris sp. nov., a new psychrotolerant methanogenic archaeon from anoxic lake sediments.

A new psychrotolerant methanogenic archaeon strain ZS was isolated from anoxic lake sediments (Switzerland). The cells of the organism were non-motile cocci, 1.5-3.5 microm in diameter. The cells aggregated and formed pseudoparenchyma. The cell wall was Gram-positive. The organism utilized methanol, mono-, di-, trimethylamine and H2/CO2 with methane production. The temperature range for growth was 1-35 degrees C with an optimum at 25 degrees C. The DNA G+C content of the organism was 43.4. mol%. Analysis of the 16S rRNA gene sequence showed that strain ZS was phylogenetically closely related to members of the genus Methanosarcina, but clearly differed from all described species of this genus (95.6-97.6% of sequence similarity). The level of DNA-DNA hybridization of strain ZS with Methanosarcina barkeri and Methanosarcina mazei was 15 and 31%, respectively. Based on the results of physiological and phylogenetic studies strain ZS can be assigned to a new species of the genus Methanasarcina. The name Methanosarcina lacustris sp. nov. is proposed. The type strain is ZS (= DSM 13486T, VKM B-2268).

Base Sequence↗

PubMed2001

Carboxydobrachium pacificum gen. nov., sp. nov., a new anaerobic, thermophilic, CO-utilizing marine bacterium from Okinawa Trough.

A new anaerobic, thermophilic, CO-utilizing marine bacterium, strain JMT, was isolated from a submarine hot vent in Okinawa Trough. Cells of strain JMT were non-motile thin straight rods, sometimes branching, with a cell wall of the Gram-positive type, surrounded with an S-layer. Chains of three to five cells were often observed. The isolate grew chemolithotrophically on CO, producing equimolar quantities of H2 and CO2 (according to the equation CO+H2O-->CO2+H2) and organotrophically on peptone, yeast extract, starch, cellobiose, glucose, galactose, fructose and pyruvate, producing H2, acetate and CO2. Growth was observed from 50 to 80 degrees C with an optimum at 70 degrees C. The optimum pH was 6.8-7.1. The optimum concentration of sea salts in the medium was 20.5-25.5 g l(-1). The generation time under optimal conditions was 7.1 h. The DNA G+C content was 33 mol %. Growth of isolate JMT was not inhibited by penicillin, but ampicillin, streptomycin, kanamycin and neomycin completely inhibited growth. The results of 16S rDNA sequence analysis revealed that strain JMT belongs to the Thermoanaerobacter phylogenetic group within the Bacillus-Clostridium subphylum of Gram-positive bacteria but represents a separate branch of this group. On the basis of morphological and physiological features and phylogenetic data, this isolate should be assigned to a new genus, for which the name Carboxydobrachium is proposed. The type species is Carboxydobrachium pacificum; the type strain is JMT (= DSM 12653T).

Bacteria, Anaerobic↗

PubMed2001

Taxonomic study of aerobic thermophilic bacilli: descriptions of Geobacillus subterraneus gen. nov., sp. nov. and Geobacillus uzenensis sp. nov. from petroleum reservoirs and transfer of Bacillus stearothermophilus, Bacillus thermocatenulatus, Bacillus thermoleovorans, Bacillus kaustophilus, Bacillus thermodenitrificans to Geobacillus as the new combinations G. stearothermophilus, G. th.

Five hydrocarbon-oxidizing strains were isolated from formation waters of oilfields in Russia, Kazakhstan and China. These strains were moderately thermophilic, neutrophilic, motile, spore-forming rods, aerobic or facultatively anaerobic. The G+C content of their DNA ranged from 49.7 to 52.3 mol%. The major isoprenoid quinone was menaquinone-7; cellular fatty acid profiles consisted of significant amounts of iso-15:0, iso-16:0 and iso-17:0 fatty acids (61.7-86.8% of the total). Based on data from 16S rDNA analysis and DNA-DNA hybridization, the subsurface isolates could be divided into two groups, one of which consisted of strains UT and X and the other of which consisted of strains K, Sam and 34T. The new strains exhibited a close phylogenetic relationship to thermophilic bacilli of 'Group 5' of Ash et al. [Ash, C., Farrow, J. A. E., Wallbanks, S. & Collins, M. D. (1991). Lett Appl Microbiol 13, 202-206] and a set of corresponding signature positions of 16S rRNA. Comparative analysis of the 16S rDNA sequences and fatty acid compositions of the novel isolates and established species of thermophilic bacilli indicated that the subsurface strains represent two new species within a new genus, for which the names Geobacillus subterraneus gen. nov., sp. nov., and Geobacillus uzenensis sp. nov. are proposed. It is also proposed that Bacillus stearothermophilus, Bacillus thermoleovorans, Bacillus thermocatenulatus, Bacillus kaustophilus, Bacillus thermoglucosidasius and Bacillus thermodenitrificans be transferred to this new genus, with Geobacillus stearothermophilus (formerly Bacillus stearothermophilus) as the type species.

Bacillus↗

PubMed2001

Thioalkalimicrobium aerophilum gen. nov., sp. nov. and Thioalkalimicrobium sibericum sp. nov., and Thioalkalivibrio versutus gen. nov., sp. nov., Thioalkalivibrio nitratis sp.nov., novel and Thioalkalivibrio denitrificancs sp. nov., novel obligately alkaliphilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria from soda lakes.

Forty-three strains of obligately chemolithoautotrophic sulfur-oxidizing bacteria were isolated from highly alkaline soda lakes in south-east Siberia (Russia) and in Kenya using a specific enrichment procedure at pH 10. The main difference between the novel isolates and known sulfur bacteria was their potential to grow and oxidize sulfur compounds at pH 10 and higher. The isolates fell into two groups that were substantially different from each other physiologically and genetically. Most of the Siberian isolates belonged to the group with a low DNA G+C content (48.0-51.2 mol%). They were characterized by a high growth rate, a low growth yield, a high cytochrome content, and high rates of oxidation of sulfide and thiosulfate. This group included 18 isolates with a DNA homology of more than 40%, and it is described here as a new genus, Thioalkalimicrobium, with two species Thioalkalimicrobium aerophilum (type species) and Thioalkalimicrobium sibericum. The other isolates, mainly from Kenyan soda lakes, fell into a group with a high DNA G+C content (61.0-65.6 mol%). In general, this group was characterized by a low growth rate, a high molar growth yield and low, but relatively equal, rates of oxidation of thiosulfate, sulfide, elemental sulfur and polythionates. The group included 25 isolates with a DNA homology of more than 30%. It was less compact than Thioalkalimicrobium, containing haloalkalophilic, carotenoid-producing, nitrate-reducing and facultatively anaerobic denitrifying strains. These bacteria are proposed to be assigned to a new genus, Thioalkalivibrio, with three species Thioalkalivibrio versutus (type species), Thioalkalivibrio denitrificans and Thioalkalivibrio nitratis. Phylogenetic analysis revealed that both groups belong to the gamma-Proteobacteria. The Thioalkalimicrobium species were closely affiliated with the neutrophilic chemolithoautotrophic sulfur bacteria of the genus Thiomicrospira, forming a new alkaliphilic lineage in this cluster. In contrast, Thioalkalivibrio was not related to any known chemolithoautotrophic taxa, but was distantly associated with anaerobic purple sulfur bacteria of the genus Ectothiorhodospira.

Alkalies↗

PubMed2001

Albibacter methylovorans gen. nov., sp. nov., a novel aerobic, facultatively autotrophic and methylotrophic bacterium that utilizes dichloromethane.

A novel genus, Albibacter, with one species, Albibacter methylovorans sp. nov., is proposed for a facultatively chemolithotrophic and methylotrophic bacterium (strain DM10T) with the ribulose bisphosphate (RuBP) pathway of C1 assimilation. The bacterium is a Gram-negative, aerobic, asporogenous, nonmotile, colourless rod that multiplies by binary fission. The organism utilizes dichloromethane, methanol, methylamine, formate and CO2/H2, as well as a variety of polycarbon compounds, as carbon and energy sources. It is neutrophilic and mesophilic. The major cellular fatty acids are straight-chain unsaturated C18:1, saturated C16:0 and cyclopropane C19:0 acids. The main ubiquinone is Q-10. The dominant phospholipids are phosphatidyl ethanolamine, phosphatidyl glycerol, phosphatidyl choline and cardiolipin. The DNA G+C content is 66.7 mol%. Strain DM10T has a very low degree of DNA-DNA hybridization (4-7%) with the type species of the genera Paracoccus, Xanthobacter, Blastobacter, Angulomicrobium, Ancylobacter and Ralstonia of RuBP pathway methylobacteria. Another approach, involving comparative 16S rDNA analysis, has shown that the novel isolate represents a separate branch within the alpha-2 subgroup of the Proteobacteria. The type species of the new genus is Albibacter methylovorans sp. nov.; the type strain is DM10T (= VKM B-2236T = DSM 13819T).

DNA, Bacterial↗

PubMed2001

Microbial thiocyanate utilization under highly alkaline conditions.

Three kinds of alkaliphilic bacteria able to utilize thiocyanate (CNS-) at pH 10 were found in highly alkaline soda lake sediments and soda soils. The first group included obligate heterotrophs that utilized thiocyanate as a nitrogen source while growing at pH 10 with acetate as carbon and energy sources. Most of the heterotrophic strains were able to oxidize sulfide and thiosulfate to tetrathionate. The second group included obligately autotrophic sulfur-oxidizing alkaliphiles which utilized thiocyanate nitrogen during growth with thiosulfate as the energy source. Genetic analysis demonstrated that both the heterotrophic and autotrophic alkaliphiles that utilized thiocyanate as a nitrogen source were related to the previously described sulfur-oxidizing alkaliphiles belonging to the gamma subdivision of the division Proteobacteria (the Halomonas group for the heterotrophs and the genus Thioalkalivibrio for autotrophs). The third group included obligately autotrophic sulfur-oxidizing alkaliphilic bacteria able to utilize thiocyanate as a sole source of energy. These bacteria could be enriched on mineral medium with thiocyanate at pH 10. Growth with thiocyanate was usually much slower than growth with thiosulfate, although the biomass yield on thiocyanate was higher. Of the four strains isolated, the three vibrio-shaped strains were genetically closely related to the previously described sulfur-oxidizing alkaliphiles belonging to the genus Thioalkalivibrio. The rod-shaped isolate differed from the other isolates by its ability to accumulate large amounts of elemental sulfur inside its cells and by its ability to oxidize carbon disulfide. Despite its low DNA homology with and substantial phenotypic differences from the vibrio-shaped strains, this isolate also belonged to the genus Thioalkalivibrio according to a phylogenetic analysis. The heterotrophic and autotrophic alkaliphiles that grew with thiocyanate as an N source possessed a relatively high level of cyanase activity which converted cyanate (CNO-) to ammonia and CO2. On the other hand, cyanase activity either was absent or was present at very low levels in the autotrophic strains grown on thiocyanate as the sole energy and N source. As a result, large amounts of cyanate were found to accumulate in the media during utilization of thiocyanate at pH 10 in batch and thiocyanate-limited continuous cultures. This is a first direct proof of a "cyanate pathway" in pure cultures of thiocyanate-degrading bacteria. Since it is relatively stable under alkaline conditions, cyanate is likely to play a role as an N buffer that keeps the alkaliphilic bacteria safe from inhibition by free ammonia, which otherwise would reach toxic levels during dissimilatory degradation of thiocyanate.

Alkalies↗

PubMed2000

A new facultatively autotrophic hydrogen- and sulfur-oxidizing bacterium from an alkaline environment.

An alkaliphilic bacterium, strain AHO 1, was isolated from an enrichment culture with hydrogen at pH 10 inoculated with a composite sample of sediments from five highly alkaline soda lakes (Kenya). This bacterium is a gram-negative, nonmotile, rod-shaped, obligately aerobic, and facultatively autotrophic hydrogen-oxidizing organism. It was able to oxidize reduced sulfur compounds to sulfate during heterotrophic growth. It utilized a wide range of organic compounds as carbon and energy sources and grew mixotrophically with hydrogen and acetate. With sulfur compounds, mixotrophic growth was observed only in acetate-limited continuous culture. The normal pH range for autotrophic growth with hydrogen was pH 8.0-10.25, with a pH optimum at 9-9.5. Growth at pH values lower than 8.0 was extremely slow. Heterotrophic growth with acetate was optimal at pH 10.0. The hydrogen-oxidizing activity of whole cells was maximal at pH 9.0 and still substantial up to pH 11. NAD-dependent hydrogenase activity was found in the soluble fraction of the cell-free extract, but no methylene blue-dependent activity in either the soluble or membrane fractions was observed. On the basis of its pH profile, the soluble hydrogenase of strain AHO 1 was a typical pH-neutral enzyme. Phylogenetic analysis revealed that strain AHO 1 belongs to the alpha-3 subgroup of the Proteobacteria with a closest relation to a recently described alkaliphilic aerobic bacteriochlorophyll a-containing bacterium "Roseinatronobacter thiooxidans."

Alkalies↗

PubMed2000

Alkaliphilic heliobacterium Heliorestis baculata sp. nov. and emended description of the genus Heliorestis.

A rod-shaped heliobacterium motile by peritrichous flagella, designated strain OS-H1, was isolated from a sample of shoreline soil of the soda lake Ostozhe (pH 9.2, total salt content 0.22%) located in the steppe of south-east Siberia. In the first few transfers, the isolate produced heat-resistant endospores. Like other heliobacteria, strain OS-H1 contained bacteriochlorophyll g and lacked intracytoplasmic membranes. The new isolate was a strict anaerobe and photoheterotroph. In the light and in the presence of organic compounds, strain OS-H1 oxidized sulfide to elemental sulfur and polysulfides, but was not capable of photoautotrophic growth. The isolate was an obligate alkaliphile able to grow at pH 8-10.2. The best growth was observed at pH 8.5-9.5, a temperature of 30 degrees C and at 5-10 g sodium carbonate l(-1). Biotin was required as a growth factor. The G+C content of strain OS-H1 was 45.0 mol%. Comparison of the 16S rRNA gene sequence to that of phototrophic bacteria showed strain OS-H1 to group within gram-positive bacteria of the family Heliobacteriaceae with the closest relationship to Heliorestis daurensis (95.6% similarity). Based on physiological, genetic and chemotaxonomic characteristics, the new heliobacterium is described as a new species of the genus Heliorestis, Heliorestis baculata.

Bacteria↗

PubMed2000

Methylopila helvetica sp. nov. and Methylobacterium dichloromethanicum sp. nov.--novel aerobic facultatively methylotrophic bacteria utilizing dichloromethane.

Eight strains of Gram-negative, aerobic, asporogenous, neutrophilic, mesophilic, facultatively methylotrophic bacteria are taxonomically described. These icl- serine pathway methylobacteria utilize dichloromethane, methanol and methylamine as well as a variety of polycarbon compounds as the carbon and energy source. The major cellular fatty acids of the non-pigmented strains DM1, DM3, and DM5 to DM9 are C18:1, C16:0, C18:0, Ccy19:0 and that of the pink-pigmented strain DM4 is C18:1. The main quinone of all the strains is Q-10. The non-pigmented strains have similar phenotypic properties and a high level of DNA-DNA relatedness (81-98%) as determined by hybridization. All strains belong to the alpha-subgroup of the alpha-Proteobacteria. 16S rDNA sequence analysis led to the classification of these dichloromethane-utilizers in the genus Methylopila as a new species - Methylopila helvetica sp.nov. with the type strain DM9 (=VKM B-2189). The pink-pigmented strain DM4 belongs to the genus Methylobacterium but differs from the known members of this genus by some phenotypic properties, DNA-DNA relatedness (14-57%) and 16S rDNA sequence. Strain DM4 is named Methylobacterium dichloromethanicum sp. nov. (VKM B-2191 = DSMZ 6343).

Bacterial Typing Techniques↗

PubMed2000

Thermanaerovibrio velox sp. nov., a new anaerobic, thermophilic, organotrophic bacterium that reduces elemental sulfur, and emended description of the genus Thermanaerovibrio.

A moderately thermophilic, organotrophic bacterium with vibrioid cells was isolated from a sample of a cyanobacterial mat from caldera Uzon, Kamchatka, Russia, and designated strain Z-9701T. Cells of strain Z-9701T were curved, Gram-negative rods, 0.5-0.7 x 2.5-5.0 microm in size, with tapering ends and with fast, wavy movement by means of lateral flagella located on the concave side of the cell. Colonies were small, white, irregular or round, 0.2 mm in diameter, and with even edges. Strain Z-9701T was an obligate anaerobe with a temperature optimum at 60-65 degrees C and a pH optimum at 7.3. It fermented glucose, fructose, mannose, N-acetyl-D-glucosamine, adonite, arginine, serine, peptone, yeast extract and Casamino acids. The fermentation products formed during growth on glucose were acetate, lactate, H2, CO2 and ethanol. Strain Z-9701T reduced elemental sulfur to H2S during organotrophic growth with glucose or peptides as energy and carbon sources. In the presence of S0, strain Z-9701T was capable of lithotrophic growth with molecular hydrogen as energy substrate and 0.1 g yeast extract l(-1) as carbon source. Sulfate, thiosulfate, nitrate, Fe(III) and sulfite were not reduced and did not stimulate growth. The G+C content of strain Z-9701T DNA was 54.6 mol%. The results of 16S rDNA sequence analyses revealed that strain Z-9701T belongs to the cluster within the Clostridium group formed by Thermanaerovibrio acidaminovorans, Dethiosulfovibrio peptidovorans, Anaerobaculum thermoterrenum and Aminobacterium colombiense, but the level of sequence similarity with the members of this cluster was not very high (87.6-92.2%). Among these organisms, Thermanaerovibrio acidaminovorans is phenotypically close to strain Z-9701T. However, the two organisms showed a relatively low level of similarity of their 16S rRNA sequences (92.2%) and of DNA-DNA hybridization (15 +/- 1%). Nevertheless, on the basis of the similar morphology and physiology of the new isolate and Thermanaerovibrio acidaminovorans, strain Z-9701T was placed in the genus Thermanaerovibrio and a new species, Thermanaerovibrio velox, proposed for it. The type strain is Z-9701T (= DSM 12556T).

Culture Media↗

PubMed2000

Proposal of Oscillochloridaceae fam. nov. on the basis of a phylogenetic analysis of the filamentous anoxygenic phototrophic bacteria, and emended description of Oscillochloris and Oscillochloris trichoides in comparison with further new isolates.

The nucleotide sequences of the genes of 16S rRNAs were determined for the type strain Oscillochloris trichoides DG-6T and three new strains of Oscillochloris-like mesophilic filamentous green bacteria. Two major clusters have been found within the family Chloroflexaceae by phylogenetic-analysis: one cluster includes thermophilic species of Chloroflexus and the second includes mesophilic strains of Oscillochloris. The degree of relatedness of these clusters was below an intergeneric level, having only 82.5-86.5% of 16S rDNA sequence similarity. These phylogenetic data correlate well with the significant physiological, biochemical and chemotaxonomical differences between members of both groups. Therefore, the Oscillochloris and Chloroflexus clusters should be considered as two separate families. The description of the new family, Oscillochloridaceae fam. nov., and emended descriptions of the genus Oscillochloris and the species Oscillochloris trichoides are presented.

Bacteria↗