Acetonema longum gen.nov.sp.nov., an H2/CO2 acetogenic bacterium from the termite,Pterotermes occidentis

A previously undescribed, H₂-oxidizing CO₂-reducing acetogenic bacterium was isolated from gut contents of the wood-feeding termite, Pterotermes occidentis. Cells of representative strain APO-1 were strictly anaerobic, Gram-negative, endospore-forming motile rods which measured 0.30–0.40×6–60 m. Cells were catalase positive, oxidase negative, and had 51.5 mol percent G+C in their DNA. Optimum conditions for growth on H₂+CO₂ were at 30–33°C and pH (initial) 7.8, and under these conditions cells formed acetate according to the equation: 4 H₂+2 CO₂CH₃COOH+2 H₂O. Other energy sources supporting good growth of strain APO-1 included glucose, ribose, and various organic acids. Acetate and butyrate were major fermentation products from most organic compounds tested, however propionate, succinate, and 1,2-propanediol were also formed from some substrates. Based on comparative analysis of 16S rRNA nucleotide sequences, strain APO-1 was related to, but distinct from, members of the genus Sporomusa. Moreover, physiological and morphological differences between strain APO-1 and the six known species of Sporomusa were significant. Consequently, it is proposed herewith that a new genus, Acetonema, be established with strain APO-1 as the type strain of the new species, Acetonema longum. A. longum may contribute to the nutrition of P. occidentis by forming acetate, propionate and butyrate, compounds which are important carbon and energy sources for termites.     

Characterization of two sulfate-reducing bacteria from the gut of the soil-feeding termite,Cubitermes speciosus

Two sulfate-reducing bacteria (SRB) were isolated from a mixed culture enriched with benzoate obtained from gut homogenate of the soil-feeding higher termite, Cubitermes speciosus. The organisms were vibrioid rods, staining Gram-negative, which performed incomplete substrate oxidation. They differed in several features. The smaller one, strain STp, was motile with a single polar flagellum. This strain differed from Desulfovibrio desulfuricans only by its inability to oxidize malate and pentanol. The bigger one, strain STg, differed from Desulfovibrio giganteus only by its nonmotility and a lower length. It is the first evidence of the presence of SRB in termite gut.     

Clostridium grantii sp. nov., a new obligately anaerobic,alginolytic bacterium isolated from mullet gut

A gram-positive, motile, rod-shaped, strictly anaerobic, sporulating bacterium was isolated from an enrichment initiated with mullet gut contents. The organism grew optimally at 30°C and pH6.5, and at a salinity of 1–10³. Out of a variety of polysaccharides tested as growth substrates, only alginate supported growth in either semidefined or complex culture medium. The organism also grew on a variety of mono- and disaccharides. Moles product per 100mol of alginate monomer degraded were: acetate, 186; ethanol, 19; formate, 54; and CO₂, 0.19. Moles product per 100mol of hexose in cellobiose or glucose degraded were: acetate, 135; ethanol,61; formate, 63: and CO₂, 61. Hydrogen was not detectable during the incubations (detection limit, <10^-5atm) and propionate, butyrate, lactate, or succinate were not produced as fermentation end products (<2 mol per 100 mol of monomer). The G+C content of DNA from the bacterium was 30.2±0.3 mol%, and the cell walls contained the peptidoglycan component meso-diaminopimelic acid. A phylogenetic analysis of the 16S rDNA sequence indicated that the organism grouped closely with members of the RNA-DNA homology group 1 of the genus Clostridium. However, it differed from other species of the genus with regard to morphology, growth temperature optimum, substrate range, and fermentation pattern and is therefore designated as a new species of Clostridium; the type strain is A-1 (DSM 8605).     

Ruminococcus hydrogenotrophicus sp. nov., a new H2/CO2-utilizing acetogenic bacterium isolated from human feces

A new H₂/CO₂-utilizing acetogenic bacterium was isolated from the feces of a non-methane-excreting human subject. The two strains S5a33 and S5a36 were strictly anaerobic, gram-positive, non-sporulating coccobacilli. The isolates grew autotrophically by metabolizing H₂/CO₂ to form acetate as sole metabolite and were also able to grow heterotrophically on a variety of organic compounds. The major end product of glucose and fructose fermentation was acetate; the strains also formed ethanol, lactate and, to a lesser extent, isobutyrate and isovalerate. The G+C content of DNA of strain S5a33 was 45.2 mol%. 16S rRNA gene sequencing demonstrated that the two acetogenic isolates were phylogenetically identical and represent a new subline within Clostridium cluster XIVa. Based on phenotypic and phylogenetic considerations, a new species, Ruminococcus hydrogenotrophicus, is proposed. The type strain of R. hydrogenotrophicus is S5a33 (DSM 10507). Furthermore, H₂/CO₂ acetogenesis appeared to be a common property of most of the species phylogenetically closely related to strain S5a33 (Clostridium coccoides, Ruminococcus hansenii, and Ruminococcus productus). Received: 11 April 1996 / Accepted: 11 June 1996     

Clostridium quinii sp. nov., a new saccharolytic anaerobic bacterium isolated from granular sludge

A new species of sporulating saccharolytic anaerobe, designated as Clostridium quinii sp. nov., is described. A gram-positive strain BS1, was isolated from the granular metanogenic sludge (UASB) from a waste-water treatment plant at a sugar refinery. The strain exhibits a series of morphological stages, developing from a spore to a small rod to a motile rod (peritrichous flagella) in the exponential growth phase, and then swelling to form cigar-shaped cells, exhibiting tumbling movements, in the late exponential growth phase before finally becoming large nonmotile ovoid cells in the stationary phase. Swelling occurs as a result of glucose being taken up and stored as a glycogen-like substance. The main fermentation products when growing on glucose is H₂, CO₂, formate, acetate and ethanol as well as small amounts of butyrate during exponential growth. Lactate is formed during the stationary phase, when glucose is abundant. Optimal conditions for growth is 40–45°C and pH of around 7.4. The type strain BS1 contains 28.0% mol G+C.     

Most probable number enumeration of H2-utilizing acetogenic bacteria from the digestive tract of animals and man

Abstract A method is proposed that allows the enrichment and most probable number estimation of H₂/CO₂-utilizing acetogenic bacteria. It is based on the difference in acetate production for serial dilutions incubated under either a test H₂/CO₂ (4:1), or a control N₂/CO₂ (4:1) headspace atmosphere. A nutritionally non-selective medium was used, containing bromoethane-sulfonic acid as inhibitor of methanogenic archaea and 10% pre-incubated clarified rumen fluid. Acetogenic bacteria were enumerated in rumen and hindgut contents of animals and in human feces. They ranged from below 10² to above 10⁸ per gram wet weight gut content and their population levels were the highest in the absence of methanogenesis. The method described therein should prove useful to better understand the diversity and ecological importance of dominant gut acetogens.     

A new H2 / CO2-using acetogenic bacterium from the rumen: Description of Ruminococcus schinkii sp. nov.

Abstract Two strains of H2 / CO2-using acetogenic bacteria were isolated from the rumen of suckling lambs. Both strains displayed a coccobacillar morphology and possessed a Gram-positive type cell wall. Numerous organic substrates, including some O-methylated aromatic compounds, were used heterotrophically. 16S rRNA gene sequencing demonstrated that the two acetogenic isolates were phylogenetically identical and represent a new subline within Clostridium cluster XIVa. Based on phenotypic and phylogenetic considerations a new species, Ruminococcus schinkii sp. nov., is proposed.     

Spirochaeta caldaria sp. nov., a thermophilic bacterium that enhances cellulose degradation by Clostridium thermocellum

Two strains of obligately anaerobic, thermophilic spirochetes were isolated from cyanobacterial mat samples collected at freshwater hot springs in Oregon and Utah, USA. The isolates grew optimally between 48° and 52°C, and did not grow at 25° or 60°C. Both strains fermented various pentoses, hexoses, and disaccharides. Amino acids or cellulose did not serve as fermentable substrates for growth. H₂, CO₂, acetate, and lactate were end products of d-glucose fermentation. On the basis of physiological characteristics, guanine + cytosine content of DNA, and comparisons of 16S ribosomal RNA sequences, it was concluded that the two isolates were representatives of a novel species of Spirochaeta for which the name Spirochaeta caldaria is proposed. One of the two strains was grown in coculture with a thermophilic cellulolytic bacterium (Clostridium thermocellum) in a medium containing cellulose as the only fermentable substrate. In the coculture cellulose was broken down at a faster rate than in the clostridial monoculture. The results are consistent with the suggestion that interactions between cellulolytic bacteria and non-cellulolytic spirochetes enhance cellulose breakdown in natural environments in which cellulose-containing plant material is biodegraded.     

Enrichment and isolation of Acetitomaculum ruminis,gen. nov., sp. nov.: acetogenic bacteria from the bovine rumen

Five strains of acetogenic bacteria were isolated by selective enrichment from the rumen of a mature Hereford crossbred steer fed a typical high forage diet. Suspensions of rumen bacteria, prepared from contents collected 7 h postfeeding, blended and strained through cheesecloth, were incubated in a minimal medium containing 10% clarified rumen fluid under either H₂:CO₂ (80:20) or N₂:CO₂ (80:20) headspace atmosphere. The selection criterion was an increment of acetate in the enrichments incubated under H₂:CO₂. Periodically, the enrichment broths were plated onto agar media and presumed acetogenic bacteria subsequently were screened for acetate production. Selected acetogenic bacteria utilized a pressurized atmosphere of H₂:CO₂ to form acetate in quantities 2 to 8-fold higher than when grown under N₂:CO₂. All presumptive acetogenic isolates were derived from either the 10^-7 or 10^-8 dilutions of rumen contents. All 5 strains were Gram-positive rods, and all utilized formate, glucose and CO. One strain required, and all were stimulated by, rumen fluid. No spores were observed with phase-contast microscopy and two strains were motile. No methane was detected in the headspace of pure cultures grown under either gas phase. The isolation of these bacteria indicates that acetogenic bacteria are inhabitants of the rumen of the bovine fed a typical diet and suggests that they may be participants in the utilization of hydrogen in the rumen ecosystem. Strain 139B (= ATCC 43876) is named Acetitomaculum ruminis gen. nov., sp. nov. and is the type strain of this new species. Portions of this work were presented previously (Greening RC, Leedle JAZ (1987) Abstr Annu Meet Am Soc Microbiol I 131, pp 194)     

Clostridium neopropionicum sp. nov., a strict anaerobic bacterium fermenting ethanol to propionate through acrylate pathway

Strain X4 was isolated several years ago from an anaerobic mesophilic plant treating vegetable cannery waste waters. It was the first example of propionic fermentation from ethanol. Morphologic and physiologic characterizations of the strain are presented here. This strain is described as type strain of a new species, Clostridium neopropionicum sp. nov. Whole cells of strain X4 ferment [1-¹³C]ethanol and CO₂ to [2-¹³C]propionate, [1-¹³C]acetate and [2-¹³C]propanol, suggesting the absence of a randomizing pathway during the propionate formation. Enzymes involved in this fermentation were assayed in cell-free extracts of cells grown with ethanol as sole substrate. Alcohol dehydrogenase, aldehyde dehydrogenase, phosphate acetyl transferase, acetate kinase, pyruvate synthase, lactate dehydrogenases, and the enzymes of the acrylate pathway were detected at activities sufficient to be involved in ethanol fermentation. The same pathway may be used for the degradation of lactate or acrylate to acetate.     

Clostridium halophilium sp. nov. and C. litorale sp. nov., an obligate halophilic and a marine species degrading betaine in the Stickland reaction

Two new mesophilic, sporeforming, gram-positive, strictly anaerobic, rod-shaped bacteria were isolated which utilized betaine in the Stickland reaction. Strain M1 was obtained from pasteurized hypersaline sediments. Cells were motile rods and formed spherical terminal spores. Betaine was used with hydrogen and several amino acids as electron donors. In addition, several carbohydrates served as substrates. Growth required 1.5% NaCl with an optimum at 6.0% NaCl. The guanine plus cytosine content of the DNA was 26.9%. This strain is described as a new species, Clostridium halophilum.Strain W6 was isolated from marine sediments. Cells were motile rods and formed ovoid, subterminal spores. Betaine was used with hydrogen and several amino acids as electron donors. Carbohydrates were not fermented. Growth optimum was at 1.0% NaCl. The guanine plus cytosine content of the DNA was 26.1%. This strain is described as a new species, Clostridium litorale.Non standard abbreviations DMG N,N-dimethylglycine - TMA trimethylamine - PY peptone-yeast extract - PYG peptone-yeast extract-glucose     

Clostridium viride sp. nov., a strictly anaerobic bacterium using 5-aminovalerate as growth substrate,previously assigned to Clostridium aminovalericum

Strain T2–7, a 5-aminovalerate-fermenting bacterium previously classified as Clostridium aminovalericum, was further characterized, both physiologically and phylogenetically. Comparative sequencing analysis of the almost complete 16S rDNA revealed that strain T2–7 forms a distinct lineage within a phylogenetically coherent cluster of gram-positive bacteria currently assigned to the genus Clostridium. Strain T2–7 grew with 5-aminovalerate, 5-hydroxyvalerate, 4-hydroxybutyrate, vinylacetate, and crotonate, and required yeast extract and l-cysteine for growth. Other substrates were not utilized. The fermentation products, depending on the growth substrate, were ammonia, acetate, propionate, butyrate, and valerate. Sulphur was reduced by a mechanism not linked to energy conservation. Other acceptors were not utilized. Cells were gram-positive pointed-ended ovals, motile by means of two subpolar flagella, and possessed a gram-positive cell wall structure with an S-layer of hexagonally arranged subunits of 18.5 nm diameter. The DNA mol% G+C was 41.5. Strain T2–7 (DSM 6836) is proposed as the type strain of a new species, Clostridium viride sp. nov. Dedicated to H. A. Barker on the occasion of his 87th birthday     

Salimicrobium salexigens sp. nov., a moderately halophilic bacterium from salted hides

Two Gram-positive, moderately halophilic bacteria, designated strains 29CMI^T and 53CMI, were isolated from salted hides. Both strains were non-motile, strictly aerobic cocci, growing in the presence of 3–25% (w/v) NaCl (optimal growth at 7.5–12.5% [w/v] NaCl), between pH 5.0 and 10.0 (optimal growth at pH 7.5) and at temperatures between 15 and 40 °C (optimal growth at 37 °C). Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that both strains showed a similarity of 98.7% and were closely related to species of the genus Salimicrobium, within the phylum Firmicutes. Strains 29CMI^T and 53CMI exhibited 16S rRNA gene sequence similarity values of 97.9–97.6% with Salimicrobium album DSM 20748^T, Salimicrobium halophilum DSM 4771^T, Salimicrobium flavidum ISL-25^T and Salimicrobium luteum BY-5^T. The DNA G+C content was 50.7 mol% and 51.5 mol% for strains 29CMI^T and 53CMI, respectively. The DNA–DNA hybridization between both strains was 98%, whereas the values between strain 29CMI^T and the species S. album CCM 3517^T, S. luteum BY-5^T, S. flavidum ISL-25^T and S. halophilum CCM 4074^T were 45%, 28%, 15% and 10%, respectively, showing unequivocally that strains 29CMI^T and 53CMI constitute a new genospecies. The major cellular fatty acids were anteiso-C_15:0, anteiso-C_17:0, iso-C_15:0 and iso-C_14:0. The main respiratory isoprenoid quinone was MK-7, although small amounts of MK-6 were also found. The polar lipids of the type strain consist of diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and one glycolipid. The peptidoglycan type is A1γ, with meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of the phylogenetic analysis, and phenotypic, genotypic and chemotaxonomic characteristics, we propose strains 29CMI^T and 53CMI as a novel species of the genus Salimicrobium, with the name Salimicrobium salexigens sp. nov. The type strain is 29CMI^T (=CECT 7568^T = JCM 16414^T = LMG 25386^T).     

Desulfosporomusa polytropa gen. nov., sp. nov., a novel sulfate-reducing bacterium from sediments of an oligotrophic lake

Five strains of sulfate-reducing bacteria were isolated from the highest positive dilutions of a most probable number (MPN) series supplemented with lactate and inoculated with sediments from the oligotrophic Lake Stechlin. The isolates were endospore-forming and were motile by means of laterally inserted flagella. They stained Gram-negative and contained b-type cytochromes. CO difference spectra indicated the presence of P582 as a sulfite reductase. Phylogenetic analyses of the 16S rDNA sequences revealed that the isolates were very closely affiliated with the genus Sporomusa. However, sulfate and amorphous Fe(OH)₃, but not sulfite, elemental sulfur, MnO₂, or nitrate were used as terminal electron acceptors. Homoacetogenic growth was found with H₂/CO₂ gas mixture, formate, methanol, ethanol, and methoxylated aromatic compounds. The strains grew autotrophically with H₂ plus CO₂ in the presence or absence of sulfate. Formate, butyrate, several alcohols, organic acids, carbohydrates, some amino acids, choline, and betaine were also utilized as substrates. The growth yield with lactate and sulfate as substrate was 7.0 g dry mass/mol lactate and thus two times higher than in sulfate-free fermenting cultures. All isolates were able to grow in a temperature range of 4–37°C. Physiologically and by the presence of a Gram-negative cell wall, the new isolates resemble known Desulfosporosinus species. However, phylogenetically they are affiliated with the Gram-negative genus Sporomusa belonging to the Selenomonas subgroup of the Firmicutes. Therefore, the new isolates reveal a new phylogenetic lineage of sulfate-reducing bacteria. A new genus and species, Desulfosporomusa polytropa gen. nov., sp. nov. is proposed.Dedicated to Prof. H. G. Schlegel on the occasion of his 80th birthday.     

Desulfomonile tiedjei gen. nov. and sp. nov., a novel anaerobic,dehalogenating, sulfate-reducing bacterium

An anaerobic, dehalogenating, sulfate-reducing bacterium, strain DCB-1, is described and nutritionally characterized. The bacterium is a Gram-negative, nonmotile, non-sporeforming large rod with an unusual morphological feature which resembles a collar. The microorganism reductively dehalogenates meta substituted halobenzoates and also reduces sulfate, sulfite and thiosulfate as electron acceptors. The bacterium requires nicotinamide, 1,4-naphthoquinone and thiamine for optimal growth in a defined medium. The microorganism can grow autotrophically on H₂:CO₂ with sulfate or thiosulfate as terminal electron acceptors. It can also grow heterotrophically with pyruvate, several methoxybenzoates, formate plus sulfate or benzoate plus sulfate. It ferments pyruvate to acetate and lactate in the absence of other electron acceptors. The bacterium is inhibited by MoO _inf4 ^sup2- or SeO _inf4 ^sup2- as well as tetracycline, chloramphenicol, kanamycin or streptomycin. Cytochrome c₃ and desulfoviridin have been purified from cells grown in defined medium. 16S rRNA sequence analysis indicates the organism is a new genus of sulfate-reducing bacteria in the delta subdivision of the class Proteobacteria. We propose that the strain be named Desulfomonile tiedjei.Non-standard abbreviations PIPES piperazine-N,N-bis[2-ethanesulfonic acid] - MES 2-[N-morpholino]ethanesulfonic acid - TES N-tris[hydroxymethyl]methyl-2-aminoethanesulfonic acid - HQNO 2-N-heptyl-4-hydroxy-quinoline-N-oxide - CCCP carbonyl-cyanide-m-chlorophenylhydrazine - CM carboxymethyl     

Ectothiorhodospira vacuolata sp. nov., a new phototrophic bacterium from soda lakes

A new phototrophic bacterium was isolated from Jordanian and Kenyan alkaline salt lakes. Cells are rod shaped, 1.5 m wide and 2–4 m long, and motile by polar flagella. They divide by binary fission, and possess photosynthetic membranes as lamellar stacks similar to those in the other species of the genus Ectothiorhodospira and the brown colored Rhodospirillum species. The presence of bacteriochlorophyll a and carotenoids of the normal spirilloxanthin series is indicated by the absorption spectra of living cells. Under certain growth conditions the cells form gas vacuoles, may become immotile and float to the top of the culture medium. Sulfide and thiosulfate are used as photosynthetic electron donors. During the oxidation of sulfide to sulfate, elemental sulfur is formed, which is accumulated outside the cells. The organisms are strictly anaerobic, do not require vitamins, are moderately halophilic and need alkaline pH-values for growth. The new species Ectothiorhodospira vacuolata is proposed.     

Cytophaga xylanolytica sp. nov., a xylan-degrading,anaerobic gliding bacterium

Gliding bacteria attached in masses to, and dominated the fermentation of, xylan powder in methanogenic and sulfidogenic enrichments from various freshwater sediments. Isolates of such bacteria were all gram-negative, slender rods (0.4×4-24 m) that formed no endospores, microcysts or fruiting bodies. Representative strain XM3 was a mesophilic, aeroduric anaerobe that grew by fermentation of mono-, di-, and poly-saccharides (but not cellulose) in a mineral medium containing up to 3% NaCl. However, CO₂/HCO _inf3 ^sup- was required in media for consistent initiation of growth. Fermentation products included acetate, propionate, succinate, CO₂, and H₂. Xylan-grown cells had xylanase and various glycosidase activities that were mainly or almost entirely cell-associated, respectively. Strain XM3 was weakly catalase positive, but oxidase negative; it possessed sulphonolipids and carotenoid, but not flexirubin, pigments; and its total cellular fatty acids were dominated by C_15:0 anteiso (75%), n (13%) and iso (2%) isomers. Strain XM3 had 45.5 mol% G+C in its DNA, and partial sequencing of its 16S rRNA placed XM3 within the Bacteroides-Flavobacterium phylogenetic group. Similar strains were isolated from marine sediments. Strain XM3 is herewith proposed as the type strain of the new species, Cytophaga xylanolytica. Results, which are discussed in terms of our current concept of the genus Cytophaga, suggest that the importance of C. xylanolytica in anaerobic biopolymer decomposition has not been fully appreciated.Dedicated to Professor Norbert Pfennig, in whose laboratory this project was initiated and who recently retired after more than four decades of contributions to microbiology     

New types of acetate-oxidizing,sulfate-reducing Desulfobacter species,D. hydrogenophilus sp. nov., D. latus sp. nov., and D. curvatus sp. nov.

Sulfate-reducing bacteria with oval to rod-shaped cells (strains AcRS1, AcRS2) and vibrio-shaped cells (strains AcRM3, AcRM4, AcRM5) differing by size were isolated from anaerobic marine sediment with acetate as the only electron donor. A vibrio-shaped type (strain AcKo) was also isolated from freshwater sediment. Two strains (AcRS1, AcRM3) used ethanol and pyruvate in addition to acetate, and one strain (AcRS1) grew autotrophically with H₂, sulfate and CO₂. Higher fatty acids or lactate were never utilized. All isolates were able to grow in ammonia-free medium in the presence of N₂. Nitrogenase activity under such conditions was demonstrated by the acetylene reduction test. The facultatively lithoautotrophic strain (AcRS1), a strain (AcRS2) with unusually large cells (2×5 m), and a vibrio-shaped strain (AcRM3) are described as new Desulfobacter species, D. hydrogenophilus, D. latus, and D. curvatus, respectively.     

Clostridium saccharogumia sp. nov. and Lactonifactor longoviformis gen. nov., sp. nov., two novel human faecal bacteria involved in the conversion of the dietary phytoestrogen secoisolariciresinol diglucoside

Two anaerobic bacteria involved in the conversion of the plant lignan secoisolariciresinol diglucoside were isolated from faeces of a healthy male adult. The first isolate, strain SDG-Mt85-3Db, was a mesophilic strictly anaerobic Gram-positive helically coiled rod. Based on 16S r RNA gene sequence analysis, its nearest relatives were Clostridium cocleatum (96.7% similarity) and Clostridium ramosum (96.6%). In contrast to these species, the isolate was devoid of alpha-galactosidase and -glucosidase and did not grow on maltose, melibiose, raffinose, rhamnose and trehalose. The hypothesis that strain SDG-Mt85-3Db represents a new bacterial species of the Clostridium cluster XVIII was confirmed by DNA-DNA hybridisation experiments. The G+C content of DNA of strain SDG-Mt85-3Db (30.7+/-0.8 mol%) was comparable with that of Clostridium butyricum, the type species of the genus Clostridium. The name Clostridium saccharogumia is proposed for strain SDG-Mt85-3Db (=DSM 17460T=CCUG 51486T). The second isolate, strain ED-Mt61/PYG-s6, was a mesophilic strictly anaerobic Gram-positive regular rod. Based on 16S rRNA gene sequence analysis, its nearest relatives were Clostridium amygdalinum (93.3%), Clostridium saccharolyticum (93.1%) and Ruminococcus productus (93.0%). The isolate differed from these species in its ability to dehydrogenate enterodiol. It also possessed alpha-arabinosidase and -galactosidase and had a higher G+C content of DNA (48.0 mol%). According to these findings, it is proposed to create a novel genus, Lactonifactor, and a novel species, Lactonifactor longoviformis, to accommodate strain ED-Mt61/PYG-s6. The type strain is DSM 17459T (=CCUG 51487T).     

Mesoflavibacter zeaxanthinifaciens gen. nov., sp. nov., a novel zeaxanthin-producing marine bacterium of the family Flavobacteriaceae

A novel strictly aerobic, gliding, Gram-negative, rod-shaped, halo- and mesophilic bacterium (TD-ZX30(T)) was isolated from a seawater sample collected on the Pacific coastline of Japan near Kamakura City (Fujisawa, Kanagawa). The temperature range for growth of TD-ZX30(T) was between 16 and 44 degrees C. The DNA G+C content was 32.0mol%. The predominant fatty acids were iso-C(15:1) G, iso-C(15:0), iso-C(16:0) 3-OH, iso-C(15:0) 3-OH, Summed feature (iso-C(15:0) 2-OH and/or C(16:1)omega7c), iso-C(17:0) 3-OH, and C(15:0). MK-6 was the only respiratory quinone. Zeaxanthin was the major carotenoid pigment produced but flexirubin-type pigments were not produced. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that TD-ZX30(T) belonged to a distinct lineage in the family Flavobacteriaceae, sharing 93.9% sequence similarity with the nearest species Olleya marilimosa. TD-ZX30(T) could be distinguished from the other members of the family Flavobacteriaceae by a number of chemotaxonomic and phenotypic characteristics. The results of polyphasic taxonomic analyses suggested that TD-ZX30(T) represents a novel genus and a novel species, for which the name Mesoflavibacter zeaxanthinifaciens gen. nov., sp. nov. is proposed. The type strain is TD-ZX30(T) (=NBRC 102119=CCUG 53614=DSM 18436).