Peritrichous Flagella Research Articles

Isolation and characterization of a new carbendazim-degrading Ralstonia sp. strain

A bacterial strain 1-1 capable of utilizing carbendazim was isolated from carbendazim-treated Qiyang red soils Hunan Province, China. It is gram-negative, rod-shaped, motile with peritrichous flagella, which formed round, smooth, convex and transparent colonies of about 1.1 mm diameter after 3 days of incubation on the isolation and purification medium using carbendazim as the sole carbon and energy sources. The degradation ratios of carbendazim by strain 1-1 were 19.16 and 95.96 in the carbendazim (500 mg/l)-degrading medium and the carbendazim (500 mg/l)-degrading medium supplemented with yeast extract (150 mg/l) within 24 days, respectively. Strain 1-1 was identified as Ralstonia sp. (β-Proteobacteria) based on the results of phenotypic features, G+C mol and phylogenetic analysis of 16S rDNA. Strain 1-1 could become a new bacterial resource for biodegrading carbendazim and might play a bioremediation role for soils contaminated by carbendazim.

Ochrobactrum anthropi and Delftia acidovorans to Bacteremia in a Patient With a Gunshot Wound

We describe a case of bacteremia involving Ochrobactrum anthropi and Delftia acidovorans in a patient who suffered a thoracoabdominal gunshot wound. Human infections with each of these organisms are reviewed, including microbiologic characteristics for identification and proper antimicrobial treatment. The possible sources of infection in this particular patient are discussed.

Pontibacillus chungwhensis gen. nov., sp. nov., a moderately halophilic Gram-positive bacterium from a solar saltern in Korea

Three moderately halophilic, spore-forming strains, designated BH030062T, BH030049 and BH030080, were isolated from a solar saltern in Korea. Phylogenetic analyses and comparative 16S rRNA gene sequence studies revealed that the isolates represent a novel distinct monophyletic lineage within the phyletic group classically defined as the genus Bacillus and are most closely related to members of the genera Gracilibacillus (93.7-95.1 % similarity), Virgibacillus (93.5-94.8 %), Halobacillus (94.8-95.9 %), Filobacillus (94.4-94.8 %) and Lentibacillus (93.3-93.7 %). Strain BH030062T was strictly aerobic, rod-shaped, Gram-positive and motile by means of peritrichous flagella. It grew in the presence of 1-15 % (w/v) NaCl and at temperatures of 15-45 degrees C. The cell wall peptidoglycan contained A1gamma-meso-diaminopimelic acid as the diagnostic diamino acid. The predominant cellular fatty acids were iso-C(15 : 0), anteiso-C(15 : 0) and iso-C(16 : 0). DNA G+C content was about 41 mol% and the major isoprenoid quinone was MK-7. On the basis of their physiological and molecular properties, the isolates represent a new genus, Pontibacillus gen. nov., and novel species, Pontibacillus chungwhensis sp. nov. The type strain is BH030062T (=KCTC 3890T=DSM 16287T).

Exiguobacterium oxidotolerans sp. nov., a novel alkaliphile exhibiting high catalase activity

A novel alkaliphile was isolated from a drain of a fish processing plant. The isolate grew at a pH range of 7-10. Cells were Gram-positive, facultatively aerobic, motile rods with peritrichous flagella. Colonies were orange or yellow in colour. Catalase and oxidase reactions were positive. The isolate grew in 0-12 % NaCl but not above 15 % NaCl. Its cell extract exhibited 567 times higher catalase activity than an Escherichia coli cell extract. The major cellular fatty acids were iso-C(13 : 0), anteiso-C(13 : 0), iso-C(15 : 0), iso-C(16 : 0), iso-C(17 : 0), anteiso-C(17 : 0) and iso-C(17 : 1). Its DNA G+C content was 46.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing and chemotaxonomic data indicated that strain T-2-2(T) is a member of the genus Exiguobacterium. DNA-DNA hybridization revealed a low relatedness of the isolate to several phylogenetic neighbours (less than 25 %). On the basis of phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, the isolate merits classification as a novel species, for which the name Exiguobacterium oxidotolerans sp. nov. is proposed. The type strain is T-2-2(T) (=JCM 12280(T)=NCIMB 13980(T)).

Mahella australiensis gen. nov., sp. nov., a moderately thermophilic anaerobic bacterium isolated from an Australian oil well

A novel Gram-positive, anaerobic and moderately thermophilic bacterium, strain 50-1 BON(T), was isolated from an Australian terrestrial oil reservoir. Cells were spore-forming straight rods, motile by peritrichous flagella. The optimum growth conditions were 50 degrees C, pH 7.5 and 0.1 % NaCl. Strain 50-1 BON(T) fermented arabinose, cellobiose, fructose, galactose, glucose, mannose, sucrose, xylose and yeast extract. Glucose was fermented mainly into lactate, formate, hydrogen and CO(2). The major end product of pyruvate fermentation was acetate together with H(2) and CO(2). Thiosulfate, sulfate, elemental sulfur and nitrate were not used as terminal electron acceptors. The DNA G+C content was 55.5 mol%. The closest phylogenetic relative of strain 50-1 BON(T) was Thermoanaerobacterium thermosulfurigenes (16S rRNA gene sequence similarity of 85.7 %). As strain 50-1 BON(T) was physiologically and phylogenetically different from members of the order 'Thermoanaerobacteriales', it is proposed that strain 50-1 BON(T) (=DSM 15567(T)=CIP 107919(T)) be classified as the type strain of a novel species of a new genus, Mahella australiensis gen. nov., sp. nov.

Alkalibacterium psychrotolerans sp. nov., a psychrotolerant obligate alkaliphile that reduces an indigo dye

A psychrotolerant, obligately alkaliphilic bacterium, IDR2-2(T), which is able to reduce indigo dye was isolated from a fermented polygonum indigo (Polygonum tinctorium Lour.) produced in Date, Hokkaido, using a traditional Japanese method. The isolate grew at pH 9-12 but not at pH 7-8. It was a Gram-positive, facultatively anaerobic, straight rod-shaped bacterium with peritrichous flagella. The isolate grew in 0-17 % (w/v) NaCl but not at NaCl concentrations higher than 18 % (w/v). Its major cellular fatty acids were C(14 : 0), C(16 : 0), C(16 : 1)9c and C(18 : 1)9c, and its DNA G+C content was 40.6 mol%. dl-lactic acid was the major end-product from d-glucose. No quinones could be detected. The peptidoglycan type was A4beta, Orn-d-Glu. A phylogenetic analysis based on 16S rRNA gene sequence data indicated that strain IDR2-2(T) is a member of the genus Alkalibacterium. DNA-DNA hybridization revealed low relatedness (less than 25 %) between the isolate and two phylogenetically related strains, Alkalibacterium olivapovliticus and Marinilactibacillus psychrotolerans. On the basis of phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, the isolate merits classification as a novel species, for which the name Alkalibacterium psychrotolerans sp. nov. is proposed. The type strain is IDR2-2(T) (=JCM 12281(T)=NCIMB 13981(T)).

Bacillus asahii sp. nov., a novel bacterium isolated from soil with the ability to deodorize the bad smell generated from short-chain fatty acids

In a screening campaign to isolate strains with the ability to remove the bad smell associated with animal faeces, strain MA001(T) was isolated from a soil sample obtained from Shizuoka prefecture, Japan. The isolate grew at pH 6-9 but not at pH 10. Cells were Gram-positive, straight rods with peritrichous flagella and produced ellipsoidal spores. The isolate was positive for catalase and oxidase tests but negative for indole production, deamination of phenylalanine and H(2)S production. The isolate did not produce acid from any carbohydrates tested and could not grow in more than 2 % NaCl. The DNA G+C content was 39.4 mol%. The cellular fatty acids profile consisted of significant amount of C(15) branched-chain fatty acids, iso-C(15 : 0) and anteiso-C(15 : 0). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain MA001(T) was closely related to Bacillus simplex and Bacillus psychrosaccharolyticus. DNA-DNA hybridization revealed a low relatedness of the isolate to several phylogenetically close neighbours (less than 9 %). On the basis of the phenotypic characteristics observed, phylogenetic data based on 16S rRNA gene sequencing and DNA-DNA relatedness data, it is concluded that the isolate should be classified as representing a novel species, for which the name Bacillus asahii is proposed. The type strain is MA001(T) (=JCM 12112(T)=NCIMB 13969(T)).

Swaminathania salitolerans gen. nov., sp. nov., a salt-tolerant, nitrogen-fixing and phosphate-solubilizing bacterium from wild rice (Porteresia coarctata Tateoka).

A novel species, Swaminathania salitolerans gen. nov., sp. nov., was isolated from the rhizosphere, roots and stems of salt-tolerant, mangrove-associated wild rice (Porteresia coarctata Tateoka) using nitrogen-free, semi-solid LGI medium at pH 5.5. Strains were Gram-negative, rod-shaped and motile with peritrichous flagella. The strains grew well in the presence of 0.35% acetic acid, 3% NaCl and 1% KNO3, and produced acid from l-arabinose, d-glucose, glycerol, ethanol, d-mannose, d-galactose and sorbitol. They oxidized ethanol and grew well on mannitol and glutamate agar. The fatty acids 18 : 1omega7c/omega9t/omega12t and 19 : 0cyclo omega8c constituted 30.41 and 11.80% total fatty acids, respectively, whereas 13 : 1 AT 12-13 was found at 0.53%. DNA G+C content was 57.6-59.9 mol% and the major quinone was Q-10. Phylogenetic analysis based on 16S rRNA gene sequences showed that these strains were related to the genera Acidomonas, Asaia, Acetobacter, Gluconacetobacter, Gluconobacter and Kozakia in the Acetobacteraceae. Isolates were able to fix nitrogen and solubilized phosphate in the presence of NaCl. Based on overall analysis of the tests and comparison with the characteristics of members of the Acetobacteraceae, a novel genus and species is proposed for these isolates, Swaminathania salitolerans gen. nov., sp. nov. The type strain is PA51T (=LMG 21291T=MTCC 3852T).

Emendation of the genus Acidomonas Urakami, Tamaoka, Suzuki and Komagata 1989.

The genus Acidomonas and the species Acidomonas methanolica were recharacterized by using the type strain (NRIC 0498(T)), three reference strains and 10 methanol-utilizing bacteria that were isolated from activated sludge from three different sewage-treatment plants in Tokyo. Based on 16S rDNA sequences, all strains formed a single cluster within the Acetobacteraceae that was clearly different from the genera Acetobacter, Gluconobacter, Gluconacetobacter, Asaia and KOZAKIA: The 14 strains were identified as a single species, Acidomonas methanolica, by DNA-DNA similarities, showed DNA G+C contents that ranged from 62 to 63 mol% and had Q-10 as the major quinone, accounting for >87 % of total ubiquinones. Cells of Acidomonas methanolica had a single polar flagellum (or occasionally polar tuft flagella); this differs from a previous study that described peritrichous flagella. Oxidation of acetate was positive for all strains, but oxidation of lactate was weakly positive and varied with strains. Dihydroxyacetone was not produced from glycerol. Pantothenic acid was an essential requirement for growth. The strains tested grew at mostly the same extent at pH 3.0-8.0. Therefore, Acidomonas methanolica should be regarded as acidotolerant, not acidophilic. The descriptions of the genus Acidomonas and the species Acidomonas methanolica Urakami, Tamaoka, Suzuki and Komagata 1989 are emended with newly obtained data.

Anaerobranca californiensis sp. nov., an anaerobic, alkalithermophilic, fermentative bacterium isolated from a hot spring on Mono Lake.

A novel, obligately anaerobic, alkalithermophilic, chemo-organotrophic bacterium was isolated from the sediment of an alkaline hot spring located on Paoha Island in Mono Lake, California, USA. This rod-shaped bacterium was motile via peritrichous flagella. Isolated strains grew optimally in 5-25 g NaCl l(-1), at pH 9.0-9.5 and at a temperature of 58 degrees C and were fermentative and mainly proteolytic, utilizing peptone, Casamino acids and yeast extract. Optimal growth was seen in the presence of elemental sulfur, polysulfide or thiosulfate with concomitant reduction to hydrogen sulfide. Sulfite was also formed in an equal ratio to sulfide during reduction of thiosulfate. The novel isolate could also reduce Fe(III) and Se(IV) in the presence of organic matter. On the basis of physiological properties, 16S rRNA gene sequence and DNA-DNA hybridization data, strain PAOHA-1(T) (=DSM 14826(T)=UNIQEM 227(T)) belongs to the genus Anaerobranca and represents a novel species, Anaerobranca californiensis sp. nov.

Chemotaxis-mediated biodegradation of cyclic nitramine explosives RDX, HMX, and CL-20 by Clostridium sp. EDB2

Cyclic nitramine explosives, RDX, HMX, and CL-20 are hydrophobic pollutants with very little aqueous solubility. In sediment and soil environments, they are often attached to solid surfaces and/or trapped in pores and distribute heterogeneously in aqueous environments. For efficient bioremediation of these explosives, the microorganism(s) must access them by chemotaxis ability. In the present study, we isolated an obligate anaerobic bacterium Clostridium sp. strain EDB2 from a marine sediment. Strain EDB2, motile with numerous peritrichous flagella, demonstrated chemotactic response towards RDX, HMX, CL-20, and NO 2 −. The three explosives were biotransformed by strain EDB2 via N-denitration with concomitant release of NO 2 −. Biotransformation rates of RDX, HMX, and CL-20 by the resting cells of strain EDB2 were 1.8 ± 0.2, 1.1 ± 0.1, and 2.6 ± 0.2 nmol h −1 mg wet biomass −1 (mean ± SD; n=3), respectively. We found that commonly seen RDX metabolites such as TNX, methylenedinitramine, and 4-nitro-2,4-diazabutanal neither produced NO 2 − during reaction with strain EDB2 nor they elicited chemotaxis response in strain EDB2. The above data suggested that NO 2 − released from explosives during their biotransformation might have elicited chemotaxis response in the bacterium. Biodegradation and chemotactic ability of strain EDB2 renders it useful in accelerating the bioremediation of explosives under in situ conditions.

Wautersia gen. nov., a novel genus accommodating the phylogenetic lineage including Ralstonia eutropha and related species, and proposal of Ralstonia [Pseudomonas] syzygii (Roberts et al. 1990) comb. nov.

Comparative 16S rDNA sequence analysis indicates that two distinct sublineages, with a sequence dissimilarity of >4 % (bootstrap value, 100 %), exist within the genus RALSTONIA: the Ralstonia eutropha lineage, which comprises Ralstonia basilensis, Ralstonia campinensis, R. eutropha, Ralstonia gilardii, Ralstonia metallidurans, Ralstonia oxalatica, Ralstonia paucula, Ralstonia respiraculi and Ralstonia taiwanensis; and the Ralstonia pickettii lineage, which comprises Ralstonia insidiosa, Ralstonia mannitolilytica, R. pickettii, Ralstonia solanacearum and Ralstonia syzygii comb. nov. (previously Pseudomonas syzygii). This phylogenetic discrimination is supported by phenotypic differences. Members of the R. eutropha lineage have peritrichous flagella, do not produce acids from glucose and are susceptible to colistin, in contrast to members of the R. pickettii lineage, which have one or more polar flagella, produce acid from several carbohydrates and are colistin-resistant. Members of the R. pickettii lineage are viable for up to 6 days on tryptic soy agar at 25 degrees C, whereas members of the R. eutropha lineage are viable for longer than 9 days. It is proposed that species of the R. eutropha lineage should be classified in a novel genus, Wautersia gen. nov. Finally, based on the literature and new DNA-DNA hybridization data, it is proposed that Pseudomonas syzygii should be renamed Ralstonia syzygii comb. nov.

Tepidibacter formicigenes sp. nov., a novel spore-forming bacterium isolated from a Mid-Atlantic Ridge hydrothermal vent.

A novel anaerobic, Gram-positive, sporulating and strictly chemoorganoheterotrophic bacterium, designated strain DV1184(T), was isolated from a deep-sea hydrothermal vent sample from the Mid-Atlantic Ridge. The cells were short, straight rods (4 micro m long and 0.8 micro m wide) and were motile with peritrichous flagella. They grew between 35 and 55 degrees C (optimum, 45 degrees C), between pH 5.0 and 8.0 (optimum, 6.0) and at 20-60 g sea salts l(-1) (optimum sea salts concentration, 30 g l(-1)). Strain DV1184(T) was able to ferment yeast extract, tryptone, peptone, glucose, sucrose, maltose and pyruvate. The main fermentation products from glucose were (in decreasing order) formate, acetate and ethanol. The genomic DNA G+C content was 29 mol%. Phylogenetic analysis of the 16S rRNA gene located the strain within cluster XI of the lineage that encompasses the genus Clostridium and related genera in the bacterial domain. On the basis of 16S rDNA sequence comparison and physiological and biochemical characteristics, it is proposed that the isolate should be described as a novel species, Tepidibacter formicigenes sp. nov. The type strain is DV1184(T) (=CIP 107893(T)=DSM 15518(T)).

Bacillus krulwichiae sp. nov., a halotolerant obligate alkaliphile that utilizes benzoate and m-hydroxybenzoate.

Obligate alkaliphilic strains, AM31D(T) and AM11D, that utilize benzoate and m-hydroxybenzoate were isolated from soil obtained from Tsukuba, Ibaraki, Japan. The isolates grew at pH 8-10, but not at neutral pH. They were Gram-positive, facultatively anaerobic, straight rods with peritrichous flagella and produced ellipsoidal spores. The isolates reduced nitrate to nitrite and grew in 0-14 % NaCl, but not in higher concentrations. The major isoprenoid quinones were menaquinone-5, -6 and -7, and the cellular fatty acid profile consisted of significant amounts of 15-C branched-chain acids, isoC(15 : 0) and anteisoC(15 : 0). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain AM31D(T) was a member of group 6 (alkaliphiles) in the genus Bacillus. DNA-DNA hybridization revealed a low relatedness of the isolates with several phylogenetically close neighbours, including Bacillus alcalophilus and Bacillus pseudalcaliphilus (less than 19.3 %). Based on phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, it was concluded that these isolates merited classification as a new species, for which the name Bacillus krulwichiae is proposed. The type strain of this species is AM31D(T) (=NCIMB 13904(T)=JCM 11691(T)=IAM 15000(T)).

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).

Lateral flagella are required for increased cell adherence, invasion and biofilm formation by Aeromonas spp.

Two types of flagella are responsible for motility in mesophilic Aeromonas strains. A polar unsheathed flagellum is expressed constitutively that allows the bacterium to swim in liquid environments and, in media where the polar flagellum is unable to propel the cell, Aeromonas express peritrichous lateral flagella. Recently, Southern blot analysis using a DNA probe based on the Aeromonas caviae Sch3N lateral flagellin gene sequence showed a good correlation between strains positive for the DNA probe, swarming motility and the presence of lateral flagella by microscopy. Here, we conclude that the easiest method for the detection of the lateral flagellin gene(s) is by PCR (polymerase chain reaction); this showed good correlation with swarming motility and the presence of lateral flagella. This was despite the high degree of DNA heterogeneity found in Aeromonas gene sequences. Furthermore, by reintroducing the laf (lateral flagella) genes into several mesophilic lateral-flagella-negative Aeromonas wild-type strains, we demonstrate that this surface structure enhances the adhesion to and invasion of HEp-2 cells and the capacity for biofilm formation in vitro. These results, together with previous data obtained using Laf − mutants, demonstrate that lateral flagella production is a pathogenic feature due to its enhancement of the interaction with eukaryotic cell surfaces.

Marinilactibacillus psychrotolerans gen. nov., sp. nov., a halophilic and alkaliphilic marine lactic acid bacterium isolated from marine organisms in temperate and subtropical areas of Japan.

A novel marine lactic acid rod bacterium has been described for eight strains isolated from living and decomposing marine organisms collected from temperate and subtropical areas of Japan. The isolates were Gram-positive, catalase-negative, non-sporulating and motile with peritrichous flagella. They were slightly halophilic, highly halotolerant and alkaliphilic; the optimum NaCl concentration for growth was 2.0-3.75% (w/v) with a range from 0 to 17.0-20.5% (depending on the strain); the optimum pH was between 8.0 and 9.5 with a range from 6.0 to 10.0. They were psychrotolerant, growing well at -1.8 degrees C with a maximum at 40-45 degrees C and the optimum at 37-40 degrees C. Lactate yields were 87-100% per consumed glucose; the residual products were formate, acetate and ethanol with a molar ratio of approximately 2 : 1 : 1. The product composition was markedly affected by the pH of fermentation medium; at higher pH, the yield of lactate decreased (60-65% at pH 9.0) and that of other products increased conversely. The cell-wall peptidoglycan type was type A4beta, Orn-D-Glu, whereas that of the genus Alkalibacterium, the phylogenetically closest lactic acid bacterium, was type A4beta, Orn-D-Asp. The major cellular fatty acids were C16 : 0, C16 : 1delta9, C18 : 0 and C18 : 1delta9 (oleic acid). The G + C content of the DNA was 34.6-36.2 mol%. The eight isolates were phenotypically homogeneous and formed a single genomic species. The 16S rRNA gene sequence analysis indicated that the isolates constituted an independent phylogenetic lineage within the radiation of lactic acid bacteria with 96.2% similarity to the genus Alkalibacterium. The secondary structure and the nucleotide sequence of the V6 region of the 16S rRNA were characteristic of the organism among other related lactic acid genera. On the bases of phenotypic and phylogenetic distinctness, the organism was proposed to belong to a new genus and species, Marinilactibacillus psychrotolerans gen. nov., sp. nov. The type strain, M13-2(T) (G + C = 36.2 mol%), has been deposited in the IAM, NBRC, NCIMB and NRIC culture collections as IAM 14980(T), NBRC 100002(T), NCIMB 13873(T) and NRIC 0510(T), respectively.

Conexibacter woesei gen. nov., sp. nov., a novel representative of a deep evolutionary line of descent within the class Actinobacteria.

A novel Gram-positive bacterial strain was isolated from forest soil. According to its 16S rRNA sequence, this strain is a deep-rooting member of the class Actinobacteria. The 16S rRNA sequence is most closely related (approximately 94% identity) to clones of uncultured bacteria detected in different terrestrial environments, while showing only a remote relationship (approximately 90% identity or less) to sequences of cultured species. Cells of the first cultured representative of this phylogenetic cluster are small, short rods that are motile by peritrichous flagella, catalase- and oxidase-positive and grow under aerobic conditions. In liquid culture, flagella from different cells can aggregate to form networks, clearly visible under the light microscope. The peptidoglycan contains meso-diaminopimelic acid and is directly cross-linked (type A1gamma). Mycolic acids are not present. The polar lipids are phosphatidylinositol and an unidentified phospholipid. Menaquinone MK-7(H4) was detected as the predominant isoprenoid quinone. Oleic, 14-methylpentadecanoic, hexadecanoic and omega6c-heptadecenoic acids are the predominant components of the cellular fatty acid profile. The DNA G + C content is 71 mol%. The distinct phylogenetic position and the unusual combination of chemotaxonomic characteristics justify the proposal of a new genus and species, Conexibacter woesei gen. nov., sp. nov., with the type strain ID131577T (=DSM 14684T =JCM 11494T).

Caminicella sporogenes gen. nov., sp. nov., a novel thermophilic spore-forming bacterium isolated from an East-Pacific Rise hydrothermal vent.

A novel thermophilic, anaerobic, strictly chemoorganoheterotrophic bacterium, designated as AM1114T, was isolated from a deep-sea hydrothermal vent sample from the East-Pacific Rise (EPR 13 degrees N). The cells were long (3-10 microm) rods, motile with peritrichous flagella, and exhibited a gram-negative cell wall ultrastructure. In the late stationary phase of growth, cells formed an ovoid, refractile, terminal endospore. They grew at 45-65 degrees C inclusive (optimum 55-60 degrees C; doubling time approx. 45 min), at pH 4.5-8.0 inclusive (optimum pH 7.5-8.0) and at sea salt concentrations of 20-60 g l(-1) inclusive (optimum 25-30 g l(-1)). Strain AM1114T was an obligately heterotrophic bacterium able to ferment a mixture of 20 amino acids, complex proteinaceous substrates (such as yeast extract, brain-heart infusion or peptone), and carbohydrates such as glucose, galactose or maltose. The main fermentation products on glucose/yeast extract/peptone/sulfur medium were hydrogen, carbon dioxide, butyrate, ethanol, acetate, formate and L-alanine. The G+C content of the genomic DNA (determined by thermal denaturation) was 24.2+/-1 mol%. Phylogenetic analyses of the 16S rRNA gene located the strain within cluster XI of the lineage encompassing the genus Clostridium and related genera (sensu Collins et al., 1994), in the bacterial domain. On the basis of 16S rDNA sequence comparisons and physiological and biochemical characteristics, it is proposed that the isolate should be described as a novel genus, namely Caminicella gen. nov., of which Caminicella sporogenes sp. nov. is the type species. The type strain is AM1114T (= DSM 14501T = CIP 107141T).

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.