Selenihalanaerobacter shriftii gen. nov., sp. nov., a halophilic anaerobe from Dead Sea sediments that respires selenate

We isolated an obligately anaerobic halophilic bacterium from the Dead Sea that grew by respiration of selenate. The isolate, designated strain DSSe-1, was a gram-negative, non-motile rod. It oxidized glycerol or glucose to acetate + CO2 with concomitant reduction of selenate to selenite plus elemental selenium. Other electron acceptors that supported anaerobic growth on glycerol were nitrate and trimethylamine-N-oxide; nitrite, arsenate, fumarate, dimethylsulfoxide, thiosulfate, elemental sulfur, sulfite or sulfate could not serve as electron acceptors. Growth on glycerol in the presence of nitrate occurred over a salinity range from 100 to 240 g/l, with an optimum at 210 g/l. Analysis of the 16S rRNA gene sequence suggests that strain DSSe-1 belongs to the order Halanaerobiales, an order of halophilic anaerobes with a fermentative or homoacetogenic metabolism, in which anaerobic respiratory metabolism has never been documented. The highest 16S rRNA sequence similarity (90%) was found with Acetohalobium arabaticum (X89077). On the basis of physiological properties as well as the relatively low homology of 16S rRNA from strain DSSe-1 with known genera, classification in a new genus within the order Halanaerobiales, family Halobacteroidaceae is warranted. We propose the name Selenihalanaerobacter shriftii. Type strain is strain DSSe-1 (ATCC accession number BAA-73).     

Duganella phyllosphaerae sp. nov., isolated from the leaf surface of Trifolium repens and proposal to reclassify Duganella violaceinigra into a novel genus as Pseudoduganella violceinigra gen. nov., comb. nov

A bright yellow pigmented bacterium was isolated from the leaf surface of Trifolium repens in Germany. Comparative analysis of 16S rRNA gene sequences showed that this bacterium is most closely related to Duganella zoogloeoides IAM 12670(T), with a similarity of 99.3%, but revealed only a moderate similarity (96.8%) to the second Duganella species, Duganella violaceinigra YIM 31327(T). Strain T54(T) is clearly different from D. zoogloeoides IAM 12670(T) in that DNA-DNA hybridization revealed a similarity value of 46% (reciprocal 42%). Ubiquinone (Q-8) was the respiratory quinone and the predominant polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, three unknown phospholipids and one aminolipid. Strain T54(T) can be distinguished from D. zoogloeoides by the carbon substrate utilization tests of d-trehalose, cis-aconitate, trans-aconitate, glutarate and dl-3-hydroxybutyrate, and 4-hydroxybenzoate in addition to a different polar lipid profile. The name Duganella phyllosphaerae sp. nov. is proposed for this novel species, with the type strain T54(T) (=LMG 25994 = CCM 7824(T)) [corrected]. In addition, it is proposed to reclassify D. violaceinigra into a novel genus Pseudoduganella gen. nov. as the novel species Pseudoduganella violaceinigra comb. nov. because of the low 16S rRNA gene sequence similarities to the other Duganella species (<97%) and striking differences in chemotaxonomic (lipid profiles and fatty acid patterns) and other phenotypic features, including the colony pigmentation.     

Isolation and characterization of Bacillus thioparus sp. nov., chemolithoautotrophic, thiosulfate-oxidizing bacterium

A novel bacterium, strain BMP-1(T), was isolated from a continuous wastewater treatment culture system operating with a bacterial consortium. Cells of the isolate were Gram-variable, aerobic, moderately halotolerant, motile and endospore-forming rods. Strain BMP-1(T) grew chemolithoautotrophically by oxidation of thiosulfate to sulfate with a growth yield of 1.07 g protein mol(-1) of thiosulfate consumed. DNA G+C content was 43.8 mol%. Its cell wall had peptidoglycan based on m-diaminopimelic acid, and the major component of fatty acid was C(15 : 0). The 16S rRNA gene analysis showed that strain belongs to the genus Bacillus, sharing a 99.5% of sequence similarity with Bacillus jeotgali CCM 7133(T). DNA-DNA hybridization between the isolate of this study and this strain was 44%. Thus, the inclusion of strain BMP-1(T) in the genus Bacillus is suggested as a novel species and the name Bacillus thioparus sp. nov. (Type strain BMP-1(T)=BM-B-436(T)=CECT 7196(T)) is proposed. The sequence of the 16S rRNA gene has been deposited in GenBank with accession number DQ371431.     

Microlunatus terrae sp. nov., a bacterium isolated from soil

Strain BS6(T), a Gram-positive non-motile bacterium, was isolated from soil in South Korea and characterized to determine its taxonomic position. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that strain BS6T belonged to the family Propionibacteriaceae in the class Actinobacteria. Strain BS6(T) showed the highest 16S rRNA gene sequence similarity with Microlunatus soli CC-012602(T) (98.6%) and high sequence similarities with Microlunatus species (94.5-98.6%). Chemotaxonomic data revealed that the predominant fatty acids were anteiso-C(17:0), anteiso-C(15:0), summed feature 8 (C(18:1) ω7c/ω6c), and iso-C(16:0). The cell wall peptidoglycan contained (LL)-diaminopimelic acid, and the major polar lipids were diphosphatidylglycerol, and phosphatidylglycerol. Based on these data, BS6(T) (=KCTC 19858(T) =JCM 17661(T) =CCARM 9244(T) =KEMC 9004-079(T)) should be classified as a type strain of a novel species, for which the name Microlunatus terrae sp. nov. is proposed.     

Dasania marina gen. nov., sp. nov., of the order Pseudomonadales, isolated from Arctic marine sediment

An obligately aerobic bacterium, strain KOPRI 20902T, was isolated from a marine sediment in Ny-Arlesund, Spitsbergen Islands, Norway. Cells were irregular rods and motile with polar monotrichous flagellum. The optimum growth temperature was 17-22 degrees . Cells grew best in pH 7.0-10.0 and 3-4% sea salts (corresponding to 2.3-3.1% NaCl). The novel strain required Ca2+ or Mg2+ in addition to NaCl for growth. Sequence analysis of 16S rRNA gene revealed that the Arctic isolate is distantly related with established species (<92.4% sequence similarity) and formed a monophyletic group with Cellvibrio, which formed a distinct phylogenetic lineage in the order Pseudomonadales. Predominant cellular fatty acids [C16:1 omega7c/15:0 iso 2OH (45.3%), C16:0 (18.4%), ECL 11.799 (11.2%), C10:0 3OH (10.4%)]; DNA G+C content (37.0 mol%); nitrate reduction to nitrogen; absence of aesculin hydrolysis, N-acetyl-beta-glucosaminidase and esterase; no assimilation of arabinose, galactose, glucose, lactose, maltose, and trehalose differentiated the strain from the genus Cellvibrio. Based on the phylogenetic and phenotypic characteristics, Dasania marina gen. nov., sp. nov. is proposed in the order Pseudomonadales. Strain KOPRI 20902T (=KCTC 12566T=JCM 13441T) is the type strain of Dasania marina.     

Identification of anaerobic selenate-respiring bacteria from aquatic sediments

The diversity population of microorganisms with the capability to use selenate as a terminal electron acceptor, reducing it to selenite and elemental selenium by the process known as dissimilatory selenate reduction, is largely unknown. The overall objective of this study was to gain an in-depth understanding of anaerobic biotransformation of selenium in the environment, particularly anaerobic respiration, and to characterize the microorganisms catalyzing this process. Here, we demonstrate the isolation and characterization of four novel anaerobic dissimilatory selenate-respiring bacteria enriched from a variety of sources, including sediments from three different water bodies in Chennai, India, and a tidal estuary in New Jersey. Strains S5 and S7 from India, strain KM from the Meadowlands, NJ, and strain pn1, categorized as a laboratory contaminant, were all phylogenetically distinct, belonging to various phyla in the bacterial domain. The 16S rRNA gene sequence shows that strain S5 constitutes a new genus belonging to Chrysiogenetes, while strain S7 belongs to the Deferribacteres, with greater than 98% 16S rRNA gene similarity to Geovibrio ferrireducens. Strain KM is related to Malonomonas rubra, Pelobacter acidigallici, and Desulfuromusa spp., with 96 to 97% 16S rRNA gene similarity. Strain pn1 is 99% similar to Pseudomonas stutzeri. Strains S5, S7, and KM are obligately anaerobic selenate-respiring microorganisms, while strain pn1 is facultatively anaerobic. Besides respiring selenate, all these strains also respire nitrate.     

A strictly anaerobic betaproteobacterium Georgfuchsia toluolica gen. nov., sp. nov. degrades aromatic compounds with Fe(III), Mn(IV) or nitrate as an electron acceptor

A bacterium (strain G5G6) that grows anaerobically with toluene was isolated from a polluted aquifer (Banisveld, the Netherlands). The bacterium uses Fe(III), Mn(IV) and nitrate as terminal electron acceptors for growth on aromatic compounds. The bacterium does not grow on sugars, lactate or acetate. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain G5G6 belonged to the Betaproteobacteria . Its closest, but only distantly related, cultured relative is Sterolibacterium denitrificans Chol-1S^T (94.6% similarity of the 16S rRNA genes), a cholesterol-oxidizing, denitrifying bacterium. Strain G5G6 possesses the benzylsuccinate synthase A ( bssA ) gene encoding the α-subunit of Bss, which catalyzes the first step in anaerobic toluene degradation. The deduced BssA amino acid sequence is closely related to those of Azoarcus and Thauera species, which also belong to the Betaproteobacteria . Strain G5G6 is the first toluene-degrading, iron-reducing bacterium that does not belong to the Geobacteraceae within the Deltaproteobacteria . Based on phylogenetic and physiological comparison, strain G5G6 could not be assigned to a described species. Therefore, strain G5G6 (DSMZ 19032^T=JCM 14632^T) is a novel taxon of the Betaproteobacteria . We propose the name Georgfuchsia toluolica gen. nov., sp. nov.     

Granulosicoccaceae fam. nov., to include Granulosicoccus antarcticus gen. nov., sp. nov., a non-phototrophic, obligately aerobic chemoheterotroph in the order Chromatiales, isolated from Antarctic seawater

A Gram-negative, motile by tuft flagella, obligately aerobic chemoorganoheterotrophic, sphere-form bacterium, designated IMCC3135(T), was isolated from the Antarctic surface seawater of King George Island, West Antarctica. The strain was mesophilic, neutrophilic, and requiring NaCl for growth, but neither halophilic nor halotolerant. The 16S rRNA gene sequence analysis indicated that the strain was most closely related to genera of the order Chromatiales in the class Gammaproteobacteria. The most closely related genera showed less than 90% 16S rRNA gene sequence similarity and included Thioalkalispira (89.9%), Thioalkalivibrio (88.0%-89.5%), Ectothiorhodospira (87.9%-89.3%), Chromatium (88.3%-88.9%), and Lamprocystis (87.7%-88.9%), which represent three different families of the order Chromatiales. Phylogenetic analyses showed that this Antarctic strain represented a distinct phylogenetic lineage in the order Chromatiales and could not be assigned to any of the defined families in the order. Phenotypic characteristics, including primarily non-phototrophic, non-alkaliphilic, non-halophilic, and obligately aerobic chemoheterotrophic properties, differentiated the strain from other related genera. The very low sequence similarities (<90%) and distant relationships between the strain and members of the order suggested that the strain merited classification as a novel genus within a novel family in the order Chromatiales. On the basis of these taxonomic traits, a novel genus and species is proposed, Granulosicoccus antarcticus gen. nov., sp. nov., in a new family Granulosicoccaceae fam. nov. Strain IMCC3135(T) (=KCCM 42676(T)=NBRC 102684(T)) is the type strain of Granulosicoccus antarcticus.     

Syntrophorhabdus aromaticivorans gen. nov., sp. nov., the first cultured anaerobe capable of degrading phenol to acetate in obligate syntrophic associations with a hydrogenotrophic methanogen

Phenol degradation under methanogenic conditions has long been studied, but the anaerobes responsible for the degradation reaction are still largely unknown. An anaerobe, designated strain UI(T), was isolated in a pure syntrophic culture. This isolate is the first tangible, obligately anaerobic, syntrophic substrate-degrading organism capable of oxidizing phenol in association with an H(2)-scavenging methanogen partner. Besides phenol, it could metabolize p-cresol, 4-hydroxybenzoate, isophthalate, and benzoate. During the degradation of phenol, a small amount of 4-hydroxybenzoate (a maximum of 4 microM) and benzoate (a maximum of 11 microM) were formed as transient intermediates. When 4-hydroxybenzoate was used as the substrate, phenol (maximum, 20 microM) and benzoate (maximum, 92 microM) were detected as intermediates, which were then further degraded to acetate and methane by the coculture. No substrates were found to support the fermentative growth of strain UI(T) in pure culture, although 88 different substrates were tested for growth. 16S rRNA gene sequence analysis indicated that strain UI(T) belongs to an uncultured clone cluster (group TA) at the family (or order) level in the class Deltaproteobacteria. Syntrophorhabdus aromaticivorans gen. nov., sp. nov., is proposed for strain UI(T), and the novel family Syntrophorhabdaceae fam. nov. is described. Peripheral 16S rRNA gene sequences in the databases indicated that the proposed new family Syntrophorhabdaceae is largely represented by abundant bacteria within anaerobic ecosystems mainly decomposing aromatic compounds.     

Govania unica gen. nov., sp. nov., a rare biosphere bacterium that represents a novel family in the class Alphaproteobacteria

Strain LMG 31809 ^T was isolated from a top soil sample of a temperate, mixed deciduous forest in Belgium. Comparison of its 16S rRNA gene sequence with that of type strains of bacteria with validly published names positioned it in the class Alphaproteobacteria and highlighted a major evolutionary divergence from its near neighbor species which represented species of the orders Emcibacterales and Sphingomonadales. 16S rRNA amplicon sequencing of the same soil sample revealed a highly diverse community in which Acidobacteria and Alphaproteobacteria predominated, but failed to yield amplicon sequence variants highly similar to that of strain LMG 31809 ^T. There were no metagenome assembled genomes that corresponded to the same species and a comprehensive analysis of public 16S rRNA amplicon sequencing data sets demonstrated that strain LMG 31809 ^T represents a rare biosphere bacterium that occurs at very low abundances in multiple soil and water-related ecosystems. The genome analysis suggested that this strain is a strictly aerobic heterotroph that is asaccharolytic and uses organic acids and possibly aromatic compounds as growth substrates. We propose to classify LMG 31809 ^T as a novel species within a novel genus, Govania unica gen. nov., sp. nov, within the novel family Govaniaceae of the class Alphaproteobacteria. Its type strain is LMG 31809 ^T (=CECT 30155 ^T). The whole-genome sequence of strain LMG 31809 ^T has a size of 3.21 Mbp. The G + C content is 58.99 mol%. The 16S rRNA gene and whole-genome sequences of strain LMG 31809 ^T are publicly available under accession numbers OQ161091 and JANWOI000000000, respectively.     

Desulfohalophilus alkaliarsenatis gen. nov., sp. nov., an extremely halophilic sulfate- and arsenate-respiring bacterium from Searles Lake, California

A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125-330?g/L), although growth was slowest at salt-saturation. Strain SLSR-1 was also capable of growth via dissimilatory arsenate-reduction and displayed an even broader range of salinity tolerance (50-330?g/L) when grown under these conditions. Strain SLSR-1 could also grow via dissimilatory nitrate reduction to ammonia. Growth experiments in the presence of high borate concentrations indicated a greater sensitivity of sulfate-reduction than arsenate-respiration to this naturally abundant anion in Searles Lake. Strain SLSR-1 contained genes involved in both sulfate-reduction (dsrAB) and arsenate respiration (arrA). Amplicons of 16S rRNA gene sequences obtained from DNA extracted from Searles Lake sediment revealed the presence of close relatives of strain SLSR-1 as part of the flora of this ecosystem despite the fact that sulfate-reduction activity could not be detected in situ. We conclude that strain SLSR-1 can only achieve growth via arsenate-reduction under the current chemical conditions prevalent at Searles Lake. Strain SLSR-1 is a deltaproteobacterium in the family Desulfohalobiacea of anaerobic, haloalkaliphilic bacteria, for which we propose the name Desulfohalophilus alkaliarsenatis gen. nov., sp. nov.     

Rhizobium phenanthrenilyticum sp. nov., a novel phenanthrene-degrading bacterium isolated from a petroleum residue treatment system

Strain F11(T), a phenanthrene-degrading bacterium, was isolated from a petroleum residue treatment system, and classified under the genus Rhizobium based on the similarity analysis of its 16S rRNA and recA gene sequences. Strain F11(T) falls into the same phylogenetic clade with Rhizobium oryzae Alt 505(T) (96.8% 16S rRNA gene sequence similarity) and Rhizobium pseudoryzae J34A-127(T) (96.2%). Major cellular fatty acids of strain F11(T) are C(16:0) (6.24%) and summed feature 8 (C(18:1ω7c) and/or C(18:1ω6c), 76.59%), which are also the major fatty acids of R. oryzae Alt 505(T) and R. pseudoryzae J34A-127(T). The DNA G+C content of strain F11(T) was 59.3±0.4 mol%. Based on the phylogenetic analysis as well as biochemical and physiological characteristics, strain F11(T) could be separated from all recognized Rhizobium species. Strain F11(T) (=DSM 21882(T) =CCTCC AB 209029(T)) was considered to be representative of a novel species of Rhizobium, for which the name Rhizobium phenanthrenilyticum sp. nov. is proposed.     

Clostridium hathewayi sp. nov., from human faeces

A strictly anoxic, Gram-positive, sporeforming, rod-shaped bacterium was isolated from a chemostat inoculated with human faeces. The bacterium used carbohydrate as fermentable substrates, producing acetate, ethanol, carbon dioxide and hydrogen as the major products of glucose metabolism, and possessed a G + C content of 50.7 to 50.9 mol%. Comparative 16S rRNA gene sequencing showed that the unidentified bacterium represents a previously unrecognised sub-line within the Clostridium coccoides rRNA group of organisms. The nearest relatives of the unknown bacterium corresponded to Clostridium algidixylanolyticum, C. aerotolerans, C. celerecrescens, C. indolis, C. sphenoides, C. methoxybenzovorans and C. xylanolyticum but 16S rRNA sequence divergence values of >4% demonstrated that it represents a novel species. Based on the presented findings a new species, Clostridium hathewayi, is described. The type strain of Clostridium hathewayi is DSM = 13479T (= CCUG 43506 T).     

<Emphasis Type="Italic">Arthrobacter soli</Emphasis> sp. nov., a novel bacterium isolated from wastewater reservoir sediment

A novel Gram-positive bacterium, designated SYB2T, was isolated from wastewater reservoir sediment, and a polyphasic taxonomic study was conducted based on its morphological, physiological, and biochemical features, as well as the analysis of its 16S rRNA gene sequence. During the phylogenetic analysis of the strain SYB2T, results of a 16S rRNA gene sequence analysis placed this bacterium in the genus Arthrobacter within the family Micrococcaceae. SYB2T and Arthrobacter protophormiae ATCC 19271T, the most closely related species, both exhibited a 16S rRNA gene sequence similarity of 98.99%. The genomic DNA G+C content of the novel strain was found to be 62.0 mol%. The predominant fatty acid composition was anteiso-C15:0, anteiso-C17:0, iso-C16:0, and iso-C15:0. Analysis of 16S rRNA gene sequences and DNA-DNA relatedness, as well as physiological and biochemical tests, showed genotypic and phenotypic differences between strain SYB2T and other Arthrobacter species. The type strain of the novel species was identified as SYB2T (= KCTC 19291T= DSM 19449T).     

Identification of Anaerobic Selenate-Respiring Bacteria from Aquatic Sediments

The diversity population of microorganisms with the capability to use selenate as a terminal electron acceptor, reducing it to selenite and elemental selenium by the process known as dissimilatory selenate reduction, is largely unknown. The overall objective of this study was to gain an in-depth understanding of anaerobic biotransformation of selenium in the environment, particularly anaerobic respiration, and to characterize the microorganisms catalyzing this process. Here, we demonstrate the isolation and characterization of four novel anaerobic dissimilatory selenate-respiring bacteria enriched from a variety of sources, including sediments from three different water bodies in Chennai, India, and a tidal estuary in New Jersey. Strains S5 and S7 from India, strain KM from the Meadowlands, NJ, and strain pn1, categorized as a laboratory contaminant, were all phylogenetically distinct, belonging to various phyla in the bacterial domain. The 16S rRNA gene sequence shows that strain S5 constitutes a new genus belonging to Chrysiogenetes, while strain S7 belongs to the Deferribacteres, with greater than 98% 16S rRNA gene similarity to Geovibrio ferrireducens. Strain KM is related to Malonomonas rubra, Pelobacter acidigallici, and Desulfuromusa spp., with 96 to 97% 16S rRNA gene similarity. Strain pn1 is 99% similar to Pseudomonas stutzeri. Strains S5, S7, and KM are obligately anaerobic selenate-respiring microorganisms, while strain pn1 is facultatively anaerobic. Besides respiring selenate, all these strains also respire nitrate.     

Comamonas badia sp. nov., a floc-forming bacterium isolated from activated sludge

Strain IAM 14839, isolated from activated sludge in Japan, forms a visible floc and grows in the flocculated state. This bacterium is Gram-negative, rod-shaped, strictly aerobic and highly motile with a single polar flagellum. Both oxidase and catalase activities are positive. No growth was observed on sugars. The strain can grow at 20 degrees C, but does not grow at 37 degrees C. The G+C content of DNA is 66.3 mol% and Q-8 is the major quinone. The major cellular fatty acids are 16:1omega7c, 16:0, 18:1omega7c, 2OH 16:0, 3OH 10:0. The 16S rDNA sequence analysis indicated that the bacterium clustered within the genus Comamonas. On the basis of the phylogenetic analysis and phenotypic properties, it is proposed that the strain IAM 14839T be classified in a novel species of the genus Comamonas, Comamonas badia sp. nov. The type strain is IAM 14839T (=KCTC 12244T ).     

Rubidimonas crustatorum gen. nov., sp. nov., a novel member of the family Saprospiraceae isolated from a marine crustacean

A strictly aerobic, Gram-negative, reddish-orange pigmented, non-motile and rod-shaped bacterium, designated AK17-053^T was isolated from a marine crustacean (Squillidae) living on tidal flats on the coast of the Ariake Sea, Nagasaki, Japan. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the novel isolate could be affiliated with the family Saprospiraceae of the phylum Bacteroidetes and that it showed highest sequence similarity (84%) with Lewinella marina MKG-38^T. The strain could be differentiated phenotypically from recognized members of the family Saprospiraceae. The G+C content of DNA was 55.3 mol%, MK-7 was the major menaquinone and iso-C_15:0 and C_16:1ω7c were the major fatty acids. On the basis of polyphasic taxonomic studies, it was concluded that strain AK17-053^T represents a new genus of the family Saprospiraceae. We propose the name Rubidimonas crustatorum gen. nov., sp. nov. for this strain; its type strain is AK17-053^T (= MBIC08356^T = NBRC 107717^T).     

Sphingopyxis granuli sp. nov., a beta-glucosidase-producing bacterium in the family Sphingomonadaceae in alpha-4 subclass of the Proteobacteria

Strain Kw07T, a Gram-negative, non-spore-forming, rod-shaped bacterium, was isolated from granules in an Up-flow Anaerobic Sludge Blanket (UASB) bioreactor used in the treatment of brewery wastewater. 16S rRNA gene sequence analysis revealed that strain Kw07T belongs to the alpha-4 subclass of the Proteobacteria, and the highest degree of sequence similarity was determined to be to Sphingopyxis macrogoltabida IFO 15033T(97.8%). Chemotaxonomic data revealed that strain Kw07T possesses a quinone system with the predominant compound Q-10, the predominant fatty acid C18:1 omega7c, and sphingolipids, all of which corroborated our assignment of the strain to the Sphingopyxis genus. The results of DNA-DNA hybridization and physiological and biochemical tests clearly demonstrated that strain Kw07T represents a distinct species. Based on these data, Kw07T (=KCTC 12209T=NBRC 100800T) should be classified as the type strain for a novel Sphingopyxis species, for which the name Sphingopyxis granuli sp. nov. has been proposed.     

Clostridium bartlettii sp. nov., isolated from human faeces

Seven obligately anaerobic, Gram-positive, rod-shaped, spore-forming organisms isolated from human faecal specimens were characterized using phenotypic and molecular taxonomic methods. Strains of the unidentified bacterium used carbohydrates as fermentable substrates, producing acetic acid, isovaleric acid and phenylacetic acid (PAA) as the major products of glucose metabolism, and possessed a G +C content of approximately 29.8 mol%. Comparative 16S rRNA gene sequencing showed that the 7 strains were genetically highly related to each other (displaying >99.5% sequence similarity) and represent a previously unknown sub-line within the Clostridium Cluster XI. The closest described species to the novel bacterium is Clostridium glycolicum, although a 16S rRNA sequence divergence of 4% demonstrates that they represent different species. Genomic DNA-DNA pairing studies confirmed the separateness of the unknown species and C. glycolicum (30.6% similarity between the proposed type strain of the novel species, WAL 16138, and C. glycolicum ATCC 14880(T)). Based on morphologic, phenotypic and phylogenetic evidence, it is therefore proposed that the unknown bacterium be classified as C. bartlettii sp. nov. The type strain of C. bartlettii is WAL 16138(T) (= ATCCBAA-827(T)=CCUG48940(T)).     

Description of a novel indole-oxidizing bacterium Pseudomonas indoloxydans sp. nov., isolated from a pesticide-contaminated site

A Gram-negative, deep brown-pigmented Gammaproteobacteria, strain IPL-1(T), capable of oxidizing indole was isolated from a lindane-contaminated site and subjected to a polyphasic taxonomic study. Most of the physiological and biochemical properties, major fatty acids (C(18:1)omega7c, C(16:1)omega7c/iso C(15:0) 2OH and C(16:0)), estimated DNA G+C content (67.2mol%) and 16S rRNA gene sequence analysis showed that strain IPL-1(T) belonged to the genus Pseudomonas. Strain IPL-1(T) exhibited highest 16S rRNA gene sequence similarity with Pseudomonas pseudoalcaligenes (99.0%), followed by Pseudomonas alcaliphila (98.7%), Pseudomonas oleovorans (98.3%), Pseudomonas nitroreducens (98.0%), Pseudomonas mendocina (97.6%) and Pseudomonas stutzeri (97.4%). However, the DNA-DNA relatedness values between strain IPL-1(T) and the closely related taxa were between 22% and 61%. On the basis of differential phenotypic characteristics and genotypic distinctiveness, strain IPL-1(T) should be classified within the genus Pseudomonas as a novel species, for which the name Pseudomonas indoloxydans is proposed. The type strain is IPL-1(T) (=MTCC 8062(T)=JCM 14246(T)).