- Volume 56, Issue 4, 2006

Three strains (so36, so42T and wo26) representing a novel Gram-negative, obligately aerobic, bacteriochlorophyll a-containing species of the α-4 subgroup of the Proteobacteria were isolated from freshwater lakes using a high-throughput cultivation technique. The non-motile and slender rod-shaped cells formed orange–red-pigmented colonies. The main carotenoids were nostoxanthin and keto-nostoxanthin. According to the absorption spectrum, two different photosynthetic light-harvesting complexes, an LHI complex and a B800-830-type peripheral LHII complex, were present in the cells. The predominant fatty acids of strain so42T were hexadecenoic acid (16 : 1ω7c) and octadecenoic acid (18 : 1ω7c), whereas 17 : 1ω6c and 14 : 0 iso 2-OH were present in smaller amounts. The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, glycolipid and sphingoglycolipids. The major respiratory lipoquinone was ubiquinone-10, whereas ubiquinone-9 was present in smaller amounts. The three strains were cytochrome oxidase-negative and catalase-positive and formed alkaline and acid phosphatases. The strains grew chemoorganoheterotrophically in mineral media supplemented with various organic acids, amino acids or complex substrates such as peptone and yeast extract. The G+C content of the genomic DNA of strain so42T was 64·3 mol%. The three novel isolates contained the same 16S rRNA gene sequence. The 16S rRNA gene sequence similarity to the closest phylogenetic relative Sandaracinobacter sibiricus was only 92·8 %. Accordingly, the three strains represent a new genus and species, for which the name Sandarakinorhabdus limnophila gen. nov., sp. nov., is proposed, with strain so42T (=DSM 17366T=CECT 7086T) as the designated type strain.

A Gram-negative, chemoheterotrophic, facultatively anaerobic, slightly halophilic, oval-shaped marine bacterium, designated HTCC2601T, was isolated from the western Sargasso Sea by high-throughput culturing involving dilution to extinction. Although the 16S rRNA gene sequence similarity between the isolate and Salipiger mucosus was 96·5 %, phylogenetic analyses using different treeing algorithms clearly indicated that the strain forms a distinct lineage within a clade containing the recently classified genera Salipiger and Palleronia in the order Rhodobacterales of the Alphaproteobacteria. The DNA–DNA relatedness between strain HTCC2601T and S. mucosus was 26·3 %. Strain HTCC2601T utilized a wide range of carbohydrates, including hexose monomers, sugar alcohols, organic acids and amino acids, as sole carbon sources. The DNA G+C content of strain HTCC2601T was 65·4 mol%, and the predominant constituents of the cellular fatty acids were 18 : 1ω7c (79·7 %) and 11-methyl 18 : 1ω7c (7·5 %). The strain differed from members of the closely related genera Salipiger and Palleronia in its morphological, biochemical and ecological characteristics. On the basis of the taxonomic data obtained in this study, a novel genus and species, Pelagibaca bermudensis gen. nov., sp. nov., is proposed; HTCC2601T (=KCTC 12554T=JCM 13377T) is the type strain of Pelagibaca bermudensis.

A Gram-negative, rod-shaped, non-spore-forming betaproteobacterium (TRO-001DR8T) was isolated from humic-lake samples collected from northern Wisconsin, USA. On the basis of 16S rRNA gene sequence analysis, strain TRO-001DR8T belonged to the family Neisseriaceae, and the phylogenetic distance from its closest relative, Chromobacterium violaceum, was 95 %. Strain TRO-001DR8T lacked the violet pigmentation of C. violaceum and shared only 26 % DNA–DNA relatedness with C. violaceum. The DNA G+C content of strain TRO-001DR8T was 59 mol%. The predominant fatty acids were C16 : 1 ω7c + C16 : 1 ω7c 2-OH iso (52·5 %), C16 : 0 (21·7 %), C18 : 1 ω7c (8·0 %) and C12 : 0 (5·1 %). Strain TRO-001DR8T grew optimally at 35 °C and pH 6·0, did not utilize sucrose, but did use glucose, some organic acids and most protein amino acids. Biochemical, physiological, chemotaxonomic and phylogenetic analyses showed that strain TRO-001DR8T could not be assigned to any known genus of the Betaproteobacteria. Therefore, the isolate represents a novel genus and species, for which the name Aquitalea magnusonii gen. nov., sp. nov. is proposed. The type strain is TRO-001DR8T (=ATCC BAA-1216T=BCCM/LMG 23054T).

Three yellow-pigmented strains associated with rice plants were characterized by using a polyphasic approach. The nitrogen-fixing abilities of these strains were confirmed by acetylene reduction assay and nifH gene detection. The three strains were found to be very closely related, with 99·9 % 16S rRNA gene sequence similarity and greater than 70 % DNA–DNA hybridization values, suggesting that the three strains represent a single species. 16S rRNA gene sequence analysis indicated that the strains were closely related to Sphingomonas trueperi, with 99·5 % similarity. The chemotaxonomic characteristics (G+C content of the DNA of 68·0 mol%, ubiquinone Q-10 system, 2-OH as the only hydroxy fatty acid and homospermidine as the sole polyamine) were similar to those of members of the genus Sphingomonas. Based on DNA–DNA hybridization values and physiological characteristics, the three novel strains could be differentiated from other recognized species of the genus Sphingomonas. The name Sphingomonas azotifigens sp. nov. is proposed to accommodate these bacterial strains; the type strain is Y39T (=NBRC 15497T=IAM 15283T=CCTCC AB205007T).

A taxonomic study was carried out on two isolates, strains BL1T and BL11, from marine sediment collected from the East Sea, Korea. Comparative 16S rRNA gene sequence studies showed that these isolates clearly affiliated with the Gammaproteobacteria. BL1T and BL11 were most closely related to Oceanisphaera litoralis KMM 3654T (97·6 and 97·7 % 16S rRNA gene sequence similarity, respectively). The level of 16S rRNA gene sequence similarity between strains BL1T and BL11 was 99·7 %. The two isolates were Gram-negative, aerobic, moderately halophilic, and grew in 0·5–8·0 % NaCl and at 4–42 °C. Strains BL1T and BL11 shared some physiological and biochemical properties with O. litoralis KMM 3654T, although they differed in that BL1T and BL11 were able to utilize ethanol, proline and alanine. The G+C contents of the genomic DNA of strains BL1T and BL11 were 56·6 and 57·1 mol%, respectively. Both strains possessed C16 : 1 ω7c and/or iso-C15 : 0 2-OH, C16 : 0 and C18 : 1 ω7c as the major fatty acids. DNA–DNA relatedness data indicated that strains BL1T and BL11 represent a genomic species that is separate from O. litoralis KMM 3654T. On the basis of polyphasic evidence, it is proposed that strain BL1T (=KCTC 12522T=DSM 17589T) represents the type strain of a novel species, Oceanisphaera donghaensis sp. nov.

Two strains of heterotrophic, aerobic, marine bacteria, designated strains PIT1T and PIT2, were isolated from sea-water samples collected at the shallow coastal region of An-Ping Harbour, Tainan, Taiwan. Both strains were Gram-negative. Cells grown in broth cultures were straight rods that were non-motile, lacking flagella. Both strains required NaCl for growth and exhibited optimal growth at 30–35 °C, 1–4 % NaCl and pH 8. They grew aerobically and were incapable of anaerobic growth by fermentation of glucose or other carbohydrates. Cellular fatty acids were predominantly iso-branched, with C15 : 0 iso and C17 : 0 iso representing the most abundant components. The DNA G+C contents of strains PIT1T and PIT2 were 49·3 and 48·6 mol%, respectively. Phylogeny based on 16S rRNA gene sequences, together with data from phenotypic and chemotaxonomic characterization, revealed that the two isolates could be assigned to a novel genus in the family Idiomarinaceae, for which the name Pseudidiomarina gen. nov. is proposed. Pseudidiomarina taiwanensis sp. nov. is the type species of the novel genus (type strain PIT1T=BCRC 17465T=JCM 13360T).

Strains TU-16T and TU-18, two non-pigmented bacterial isolates with an optimum growth temperature of about 45 °C and an optimum pH of about 8·5–9·0, were recovered from the Furnas geothermal area on the Island of São Miguel in the Azores. Phylogenetic analysis of the 16S rRNA gene sequence of these strains indicated that they represent a novel species in a new genus of the phylum Betaproteobacteria. The major fatty acids of strains TU-16T and TU-18 were 16 : 0 and 18 : 1ω7c. Ubiquinone 8 was the major respiratory quinone and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The novel isolates were aerobic; thiosulfate was oxidized to sulfate in the presence of a metabolizable carbon source. The organism assimilated organic acids and amino acids, but did not assimilate carbohydrates or polyols. Based on phylogenetic analyses and physiological and biochemical characteristics, it is proposed that strain TU-16T (=LMG 23030T=CIP 108724T) represents the type strain of a novel species in a new genus, Tepidicella xavieri gen. nov., sp. nov.

Spongiochrysis hawaiiensis gen. et sp. nov. is described from material collected at two sites on O'ahu, Hawaiian Islands. This alga produced golden-yellow crusts on the bark of Casuarina trees and consisted of globular cells with an axial stellate chloroplast. The only form of reproduction was a specialized type of autosporulation in which a budding-like division of the mother cell produced daughter cells of different sizes. Phylogenetic analyses of the 18S rRNA gene showed that Spongiochrysis hawaiiensis is a member of the freshwater clade of the Cladophorales/Siphonocladales lineage in the green algal class Ulvophyceae. On the basis of its unicellular habit and terrestrial habitat, this species is well differentiated from all other members of the same lineage and can be considered as the first known successful step of a member of the order Cladophorales into terrestrial habitats. The implications of the description of this species with regard to both green algal evolution and conservation of little-known tropical habitats are discussed. The holotype specimen of Spongiochrysis hawaiiensis is GALW015489 and isotype specimens have also been deposited in the BISH and BM herbaria.

Strain 15T is a novel spore-forming, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard. Sulfate could be replaced by sulfite or thiosulfate. Hydrogen, formate, lactate, propionate, butyrate, hexanoate, methanol, ethanol, propanol, butanol, pyruvate, malate, succinate, fumarate, proline, alanine and glycine were used as electron donors in the presence of sulfate. Growth occurred with pyruvate as sole substrate. Optimal growth was observed at pH 7·1–7·5 and concentrations of 1–1·5 % NaCl and 0·4 % MgCl2. Strain 15T grew between 26 and 46·5 °C and optimal growth occurred at 44 °C. Therefore, strain 15T apparently cannot grow at in situ temperatures of Arctic sediments from where it was isolated, and it was proposed that it was present in the sediment in the form of spores. The DNA G+C content was 48·9 mol%. Strain 15T was most closely related to Desulfotomaculum thermosapovorans MLFT (93·5 % 16S rRNA gene sequence similarity). Strain 15T represents a novel species, for which the name Desulfotomaculum arcticum sp. nov. is proposed. The type strain is strain 15T (=DSM 17038T=JCM 12923T).

A Gram-negative, strictly anaerobic, halophilic, motile, sporulating and rod-shaped bacterium, designated strain HY-42-06T, was isolated from tidal flat sediment from Ganghwa Island in South Korea. The isolate produced glycerol, ethanol and CO2 as fermentation end-products from glucose. Strain HY-42-06T grew optimally at 35 °C, pH 7·5 and 3 % (w/v) artificial sea salts. No growth was observed in the absence of sea salts. In phylogenetic analyses based on 16S rRNA gene sequence, strain HY-42-06T showed a distinct phyletic line within the members of cluster I of the order Clostridiales. The closest phylogenetic neighbour to strain HY-42-06T was Clostridium novyi ATCC 17861T (94·91 % 16S rRNA gene sequence similarity). Several phenotypic characters readily differentiate the tidal flat isolate from phylogenetically related clostridia. On the basis of polyphasic evidence, strain HY-42-06T should be classified as a representative of a novel species, for which the name Clostridium ganghwense sp. nov. is proposed. The type strain is HY-42-06T (=IMSNU 40127T=KCTC 5146T=JCM 13193T).

Seven unidentified strictly anaerobic, Gram-negative, non-spore-forming bacteria from spoiled beer or the brewery environment were characterized. Based on 16S rRNA gene sequence analyses, all strains were affiliated to the Sporomusa sub-branch of the class ‘Clostridia’. Three of the strains were non-motile cocci, on average 1·5×1·2 μm or 1·2×1·0 μm, occurring mainly singly or in pairs. They shared nearly identical (>99 %) 16S rRNA gene sequences, being most closely related to the species of the Megasphaera–Anaeroglobus group (⩽93·9 % similarity). According to DNA–DNA hybridization results, the coccoid strains represented two genospecies, neither of which was related to any of the recognized Megasphaera species. Several phenotypic characteristics and/or DNA G+C content also differentiated the strains from each other and from their closest relatives. The other four novel strains were motile, slightly curved to helical rods, 0·6−0·8×3−50 μm or more in size. They shared identical 16S rRNA gene sequences and ribofragment patterns. The highest 16S rRNA gene similarity was found between these isolates and Pectinatus cerevisiiphilus ATCC 29359T (95·6 %) and Pectinatus frisingensis ATCC 33332T (93·6 %). The novel strains also differed from recognized Pectinatus species in their sugar utilization, proteolytic activity, catalase activity, antibiotic resistance and temperature tolerance. The results suggest that the bacteria belong to three novel species, for which the names Megasphaera paucivorans sp. nov. (type strain VTT E-032341T=DSM 16981T), Megasphaera sueciensis sp. nov. (type strain VTT E-97791T=DSM 17042T) and Pectinatus haikarae sp. nov. (type strain VTT E-88329T=DSM 16980T) are proposed.

A novel obligately anaerobic, proteolytic bacterium, designated AP15T, was isolated from lake sediments of Schirmacher Oasis, Antarctica. The bacterium produced maximum cell mass between 5 and 10 °C in an anaerobic basal medium containing 0·5 % tryptone and peptone. The strain grew optimally at a pH around 8·0 and tolerated NaCl up to a concentration of 7·5 %. It contained diphosphatidylglycerol as the major phospholipid and C15 : 0, C16 : 0 and C17 : 0 as the major cellular fatty acids. Several amino acids, including arginine, leucine, isoleucine, cysteine, glutamate and serine, supported growth. Glutamate was degraded to acetate, propionate, CO2 and H2. In addition, the strain degraded carbohydrates including glucose, raffinose, adonitol, ribose and rhamnose. The main fermentation products during growth on glucose were H2, CO2, formate, acetate, propionate and isovalerate. The DNA G+C content of the bacterium was 24 mol%. On the basis of a phylogenetic analysis, strain AP15T is identified as a close relative of Clostridium subterminale ATCC 25774T, with which it shares 99·5 % similarity at the 16S rRNA gene sequence level; however, it exhibits a low DNA–DNA binding value (55 %) to this strain at the whole-genome level. In addition to showing other major differences with respect to C. subterminale and other members of the genus Clostridium, AP15T also exhibits phenotypic differences. On the basis of these differences, strain AP15T is identified as representing a novel species of the genus Clostridium, for which the name Clostridium schirmacherense sp. nov. is proposed. The type strain is AP15T (=DSM 17394T=JCM 13289T).

Two mesophilic, anaerobic bacterial strains (ZLJ115T and L4-2) were isolated from the sludge of an anaerobic digester treating municipal solid waste and sewage in Fujian province, China. The strains were Gram-positive, spore-forming, motile rods (0·9–1·0×3·6–7·3 μm). Growth of the strains was observed at 20–42 °C and pH 6·0–9·5. Both strains fermented several mono- and disaccharides. The main fermentation products from glucose were acetate, ethanol, hydrogen and carbon dioxide. Optimal hydrogen production by the new isolates was observed at pH 8·8 and 39 °C, and 1·4 mol H2 was detected from fermentation of 1 mol glucose. The DNA G+C contents of strains ZLJ115T and L4-2 were 53·9 and 54·3 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolates represented a novel phyletic sublineage within cluster XI of the clostridia, clustering with four thermophilic species, with <93·8 % 16S rRNA gene sequence similarity to previously described species. Phenotypically, the new isolates were distinguished from their phylogenetic relatives by growing mesophilically and by fermenting a variety of pentoses, as well as their higher genome DNA G+C content. On the basis of polyphasic evidence from this study, a novel genus and species are proposed, Sporacetigenium mesophilum gen. nov., sp. nov.; strain ZLJ115T (=DSM 16796T=AS 1.5019T) is the type strain of Sporacetigenium mesophilum.

Seven strains of anaerobic Gram-positive cocci isolated from human oral sites were subjected to a comprehensive range of phenotypic and genotypic tests. 16S rRNA gene sequence analysis revealed that the strains constituted a homogeneous group that was distinct from species with validly published names, but related to Peptostreptococcus anaerobius. All oral strains tested belonged to this group, whereas all non-oral strains studied were confirmed as P. anaerobius. A novel species, Peptostreptococcus stomatis sp. nov., is proposed to accommodate these oral strains. P. stomatis is weakly saccharolytic and produces acetic, butyric, isobutyric, isovaleric and isocaproic acids as end products of fermentation. The type strain of P. stomatis is W2278T (=DSM 17678T=CCUG 51858T); the G+C content of the DNA of this strain is 36 mol%.

Two strictly anaerobic bacterial strains (YUAN-3T and X-29) were isolated from anaerobic activated sludge of molasses wastewater in a continuous stirred-tank reactor. The strains were Gram-positive, non-spore-forming, mesophilic and motile. Cells were regular rods (0·4–0·8×1·5–8·0 μm) and occurred singly, in pairs and sometimes in chains of up to eight. Autoaggregative and autofluorescent growth of strain YUAN-3T and non-aggregative growth of strain X-29 were observed at 20–44 °C and pH 3·5–9·0. Both strains hydrolysed gelatin and aesculin and fermented several kinds of mono-, di- and oligosaccharides. Fermentation end products formed from glucose were acetate, ethanol, hydrogen and carbon dioxide. The predominant cellular fatty acids were the branched-chain fatty acids iso-C16 : 0 (44·18 %) and iso-C12 : 0 (26·67 %). The DNA G+C contents of strains YUAN-3T and X-29 were 47·8 and 49·0 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolates represent a novel phyletic sublineage within the Clostridium cellulosi rRNA cluster, with <92 % 16S rRNA gene sequence similarity to currently known species. On the basis of polyphasic evidence from this study, it is proposed that the unknown bacterium should be classified in a new genus as a novel species, Ethanoligenens harbinense gen. nov., sp. nov. The type strain of Ethanoligenens harbinense is YUAN-3T (=JCM 12961T=CGMCC 1.5033T).

Strain 2327T, first cultured from vertebral abscesses of green iguanas (Iguana iguana) collected in Florida, USA, was readily distinguished from all previously described mollicutes by 16S rRNA gene sequence comparisons. Strain 2327T lacks a cell wall, ferments glucose, does not hydrolyse arginine, aesculin or urea and is sensitive to digitonin. Western blots distinguished the novel isolate serologically from the most closely related members of the Mycoplasma neurolyticum cluster. On the basis of these data, the isolate represents a novel species for which the name Mycoplasma iguanae sp. nov. is proposed. The type strain is strain 2327T (=ATCC BAA-1050T=NCTC 11745T).

A Gram-positive, rod-shaped, endospore-forming organism, strain CCUG 47242T, was isolated from a sample of industrial starch production in Sweden. 16S rRNA gene sequence analysis demonstrated that this isolate was moderately related to species of the genus Paenibacillus, with <94·4 % sequence similarity to all other hitherto described Paenibacillus species. Strain CCUG 47242T showed the greatest sequence similarity (96·5 %) to ‘Paenibacillus hongkongensis’ HKU3, a strain with a name that has not yet been validly published. Chemotaxonomic data [major menaquinone, MK-7 (98 %); major polar lipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, lysyl-phosphatidylglycerol, two unknown phospholipids, four unknown aminophospholipids; major fatty acids, iso-C16 : 0 and anteiso-C15 : 0] showed some significant differences when compared with the type species of the genus Paenibacillus, Paenibacillus polymyxa. Physiological and biochemical tests allowed clear phenotypic differentiation of strain CCUG 47242T from strain HKU3. On the basis of 16S rRNA gene sequence analysis, in combination with chemotaxonomic data, strains CCUG 47242T and HKU3 represent two novel species of a new genus of endospore-forming bacteria for which we propose the names Cohnella thermotolerans gen. nov., sp. nov. (type strain CCUG 47242T=CIP 108492T=DSM 17683T) and Cohnella hongkongensis sp. nov. (type strain HKU3T=CCUG 49571T=CIP 107898T=DSM 17642T).

The relatedness of the species Lactobacillus ingluviei and Lactobacillus thermotolerans was investigated by comparing partial sequences of the 16S rRNA gene (99·9 % similarity over 1504 bp), the hsp60 gene (98·8 % similarity over 954 bp) and the recA gene (98·5 % similarity over 452 bp) and by determining DNA–DNA binding levels (79±3 %) and genomic DNA G+C contents (50 and 49 mol%, respectively). These data, in addition to their similar biochemical characteristics, suggest that the two taxa constitute a single species. According to Rules 38 and 42 of the Bacteriological Code, they should be united under the name Lactobacillus ingluviei, with the name Lactobacillus thermotolerans as a later heterotypic synonym.

A novel anaerobic, thermophilic, CO-utilizing bacterium, strain KarT, was isolated from a hot spring of Karymskoe Lake, Kamchatka Peninsula. The cells of the novel isolate were Gram-positive, spore-forming, short rods. The bacterium grew chemolithoautotrophically on CO, producing equimolar quantities of H2 and CO2 (according to the equation CO + H2O → CO2 + H2), and in the absence of CO, under N2 in the gas phase, chemoorganoheterotrophically with yeast extract, sucrose or pyruvate. Growth was observed in the temperature range 50–70 °C, with an optimum at 60 °C, and in the pH range 6·2–8·0, with an optimum at pH 6·8. The micro-organism did not grow on solid media; it was able to grow only in semi-solid medium containing 0·5 % agar. The generation time under optimal conditions for chemolithoautotrophic growth was 1 h. The G+C content of the DNA was 46·5±1 mol%. Growth was completely inhibited by penicillin, novobiocin, streptomycin, kanamycin and neomycin. Analysis of the 16S rRNA gene sequence showed that the isolate should be assigned to the genus Carboxydocella. On the basis of the results of DNA–DNA hybridization and morphological and physiological analyses, strain KarT represents a novel species of the genus Carboxydocella, for which the name Carboxydocella sporoproducens sp. nov. is proposed. The type strain is KarT (=DSM 16521T=VKM B-2358T).