- Volume 64, Issue Pt_4, 2014

A Gram-staining-negative, rod-shaped bacterium, strain HMD2169T, was isolated from a mesotrophic artificial lake in Korea. Strain HMD2169T grew in the presence of 0–3.0 % (w/v) NaCl, at pH 5–10 and at 20–37 °C. The predominant quinone of strain HMD2169T was ubiquinone (UQ)-8. The major fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, two unidentified aminolipids and two unidentified lipids. The DNA G+C content was 59.8 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain HMD2169T was a representative of a lineage within the genus Chitinimonas . Strain HMD2169T was closely related to Chitinimonas taiwanensis (95.8 % sequence similarity) and Chitinimonas koreensis (94.6 %). On the basis of the evidence presented in this study, strain HMD2169T is a representative of a novel species of the genus Chitinimonas , for which the name Chitinimonas viridis sp. nov. is proposed with the type strain HMD2169T ( = KCTC 22839T = CECT 7703T).

A novel aerobic, non-spore-forming, non-motile, catalase- and oxidase-positive, Gram-stain-negative, coccoid to short-rod-shaped bacterial strain, designated YW11T, was isolated from soil under long-term application of triazophos. The strain was able to hydrolyse triazophos. Strain YW11T grew at 15–40 °C (optimum at 28 °C), at pH 5.0–8.0 (optimum at pH 7.5) and with 0–5.0 % (w/v) NaCl (optimum at 0.5 %). The major respiratory quinone was ubiquinone 10 (Q-10) and the major cellular fatty acids were C18 : 1ω7c, C16 : 0, C18 : 1 2-OH and C18 : 0. The genomic DNA G+C content of strain YW11T was 69.6±0.5 mol%. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, an unknown glycolipid and two unknown aminolipids. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain YW11T was a member of the genus Roseomonas , and showed the highest sequence similarity to Roseomonas cervicalis KACC 11686T (97.9 %) and Roseomonas aestuarii KACC 19645T (97.8 %) and then to Roseomonas ludipueritiae KACC 13843T (96.9 %). Strain YW11T showed low DNA–DNA relatedness with R. cervicalis KACC 11686T (32.3±2.9 %), R. aestuarii KACC 16549T (28.2±2.6 %) and R. ludipueritiae KACC 13843T (30.2±2.6 %). Based on the results of phylogenetic analysis and DNA–DNA hybridization, the whole-cell fatty acid composition as well as biochemical characteristics, strain YW11T was clearly distinguished from all recognized species of the genus Roseomonas and should be assigned to a novel species of the genus Roseomonas , for which the name Roseomonas rhizosphaerae sp. nov. is proposed. The type strain is YW11T ( = KACC 17225T = CCTCC AB2013041T).

Three strains, LMG 27748T, LMG 27749 and LMG 27882 with identical MALDI-TOF mass spectra were isolated from samples taken from the brewery environment. Analysis of the 16S rRNA gene sequence of strain LMG 27748T revealed that the taxon it represents was closely related to type strains of the species Gluconobacter albidus (100 % sequence similarity), Gluconobacter kondonii (99.9 %), Gluconobacter sphaericus (99.9 %) and Gluconobacter kanchanaburiensis (99.5 %). DNA–DNA hybridization experiments on the type strains of these species revealed moderate DNA relatedness values (39–65 %). The three strains used d-fructose, d-sorbitol, meso-erythritol, glycerol, l-sorbose, ethanol (weakly), sucrose and raffinose as a sole carbon source for growth (weak growth on the latter two carbon sources was obtained for strains LMG 27748T and LMG 27882). The strains were unable to grow on glucose-yeast extract medium at 37 °C. They produced acid from meso-erythritol and sucrose, but not from raffinose. d-Gluconic acid, 2-keto-d-gluconic acid and 5-keto-d-gluconic acid were produced from d-glucose, but not 2,5-diketo-d-gluconic acid. These genotypic and phenotypic characteristics distinguish strains LMG 27748T, LMG 27749 and LMG 27882 from species of the genus Gluconobacter with validly published names and, therefore, we propose classifying them formally as representatives of a novel species, Gluconobacter cerevisiae sp. nov., with LMG 27748T ( = DSM 27644T) as the type strain.

A Gram-staining-negative bacterium, strain TS-T4T, was isolated from Tuosu Lake, a saline lake (salinity 5.4 %, w/w) in Qaidam basin, Qinghai, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain TS-T4T were non-spore-forming rods, 0.4–0.8 µm wide and 1.7–2.3 µm long, and motile by means of a single polar flagellum. Strain TS-T4T was strictly heterotrophic, aerobic and catalase- and oxidase-positive. Growth was observed in the presence of 0–7.0 % (w/v) NaCl (optimum, 3.0–4.0 %) and at 4–40 °C (optimum, 30–35 °C) and pH 7.0–10.5 (optimum, pH 8.5–9.0). Strain TS-T4T contained Q-8 as the sole respiratory quinone and phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids, as for other members of the genus Rheinheimera . The predominant fatty acids (>10 %) were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, C17 : 1ω8c and C18 : 1ω7c. The DNA G+C content was 50.2 mol% (T m). Phylogenetic trees based on sequences of the 16S rRNA gene and a conserved portion of the gyrase B gene (gyrB) showed that strain TS-T4T was associated with the genus Rheinheimera ; the strain showed the highest 16S rRNA gene sequence similarity to Rheinheimera longhuensis LH2-2T (97.1 %) and then to Rheinheimera pacifica KMM 1406T (97.0 %). DNA–DNA relatedness of strain TS-T4T with R. longhuensis LH2-2T and R. pacifica NBRC 103167 was 53±2.5 and 48±2 %, respectively. Based on the data presented, it is concluded that TS-T4T represents a novel species of the genus Rheinheimera , for which the name Rheinheimera tuosuensis sp. nov. is proposed. The type strain is TS-T4T ( = CGMCC 1.12461T = JCM 19264T).

A polyvinyl-alcohol-degrading marine bacterium was isolated from plastic rope litter found in Tokyo Bay, Japan. The isolated strain, Zumi 95T, was a Gram-reaction-negative, non-spore-forming and facultatively anaerobic chemo-organotroph. The major respiratory quinone was Q-10. The predominant fatty acids were C18 : 1ω7c and C16 : 0. On the basis of 16S rRNA gene sequence analysis, the isolated strain was closely affiliated with members of the genus Thalassospira in the class Alphaproteobacteria . The DNA G+C content of the novel strain was 55.1 mol%. The hybridization values for DNA–DNA relatedness between this strain and four reference strains representing species of the genus Thalassospira were significantly lower than that accepted as the phylogenetic definition of a species. On the basis of differences in taxonomic characteristics, the isolated strain represents a novel species of the genus Thalassospira for which the name Thalassospira povalilytica sp. nov. (type strain Zumi 95T = JCM 18746T = DSM 26719T) is proposed.

The genus Rhodospirillum is represented by four species, with three of them showing phylogenetic divergence compared to the type species, Rhodospirillum rubrum . Differences in the major diagnostic properties such as internal photosynthetic membranes, quinones, fatty acids, carotenoid composition and a few other phenotypic properties warrant the reclassification of members of this genus. Resultantly, a new genus, Pararhodospirillum gen. nov., is proposed based on the analysis of nine strains to accommodate Rhodospirillum photometricum , Rhodospirillum sulfurexigens and Rhodospirillum oryzae as Pararhodospirillum photometricum comb. nov., Pararhodospirillum sulfurexigens comb. nov. and Pararhodospirillum oryzae comb. nov., respectively. The type species of the genus is Pararhodospirillum photometricum comb. nov. An emended description of the genus Rhodospirillum is also proposed.

A Gram-stain-negative, oxidase and phosphatase-positive and catalase-negative, short rod-shaped bacterium was isolated from sediment of a drinking water reservoir in Germany. Based on 16S rRNA gene sequence and phenotypic properties, the bacterium belongs to the genus Rhodoferax within the family Comamonadaceae . The new taxon differed from related species mainly with respect to its fatty acid composition, low growth temperature, lack of pigments in young cultures and ability to utilize glycerol and d-mannose but not urea. The major fatty acids were C16 : 1ω7c and/or iso-C15 : 0 2-OH, C16 : 0, and C18 : 1ω7c. The only ubiquinone detected was ubiquinone Q-8. The DNA G+C content was 60.3–61 mol%. Because of the phenotypic and genotypic differences from the most closely related taxa, the new strain represents a novel species for which the name Rhodoferax saidenbachensis sp. nov. is proposed. The type strain is ED16T ( = CCUG 57711T = ATCC BAA-1852T = DSM 22694T). An emended description of the genus Rhodoferax is proposed. Based on the results of this study, strain T118T (Albidiferax ferrireducens) is properly placed in the genus Rhodoferax as Rhodoferax ferrireducens.

A novel bacterium, strain MUSC 273T, was isolated from mangrove sediments of the Tanjung Lumpur river in the state of Pahang in peninsular Malaysia. The bacterium was yellow-pigmented, Gram-negative, rod-shaped and non-spore-forming. The taxonomy of strain MUSC 273T was studied by a polyphasic approach and the organism showed a range of phenotypic and chemotaxonomic properties consistent with those of the genus Novosphingobium . The 16S rRNA gene sequence of strain MUSC 273T showed the highest sequence similarity to those of Novosphingobium indicum H25T (96.8 %), N. naphthalenivorans TUT562T (96.4 %) and N. soli CC-TPE-1T (95.9 %) and lower sequence similarity to members of all other species of the genus Novosphingobium . Furthermore, in phylogenetic analyses based on the 16S rRNA gene sequence, strain MUSC 273T formed a distinct cluster with members of the genus Novosphingobium . DNA–DNA relatedness of strain MUSC 273T to the type strains of the most closely related species, N. indicum MCCC 1A01080T and N. naphthalenivorans DSM 18518T, was 29.2 % (reciprocal 31.0 %) and 17 % (reciprocal 18 %), respectively. The major respiratory quinone was ubiquinone Q-10, the major polyamine was spermidine and the DNA G+C content was 63.3±0.1 mol%. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine and sphingoglycolipid. The major fatty acids were C18 : 1ω7c, C17 : 1ω6c, C16 : 0, C15 : 0 2-OH and C16 : 1ω7c. Comparison of BOX-PCR fingerprints indicated that strain MUSC 273T represented a unique DNA profile. The combined genotypic and phenotypic data showed that strain MUSC 273T represents a novel species of the genus Novosphingobium , for which the name Novosphingobium malaysiense sp. nov. is proposed. The type strain is MUSC 273T ( = DSM 27798T = MCCC 1A00645T = NBRC 109947T).

Two motile, Gram-staining-negative, aerobic, rod-shaped bacteria designated strains E48T and E49T were isolated from the rhizosphere of Hordeum secalinum from a natural salt meadow near Münzenberg, Germany. 16S rRNA gene sequence similarity analysis revealed that strains E48T and E49T shared similarities of 97.6 % with Rheinheimera pacifica KMM 1406T and 98.5 % with Rheinheimera nanhaiensis E407-8T, respectively. Major fatty acids of strain E48T were C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C17 : 1ω8c, and of strain E49T were C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C18 : 1ω7c. The DNA G+C contents were 50.5 mol% (E48T) and 50.0 mol% (E49T). Strains E48T and E49T grew at 4–37 °C (optimum 28 °C) and with 0–6 % NaCl (optimum 0–3 %) and 0–5 % NaCl (optimum 0–3 %), respectively. The potential for nitrogen fixation by strains E48T and E49T was evaluated by molecular techniques and the acetylene reduction assay. The DNA–DNA hybridization, physiological and molecular data demonstrated that strains E48T and E49T represent two novel species of the genus Rheinheimera , and therefore the names Rheinheimera hassiensis sp. nov. (type strain E48T = LMG 27268T = KACC 17070T) and Rheinheimera muenzenbergensis sp. nov. (type strain E49T = LMG 27269T = KACC 17071T) are proposed.

Two methanotrophic bacteria, strains R-45377T and R-45370, were respectively isolated from a slurry pit of a cow stable and from a denitrification tank of a wastewater treatment plant in Belgium. The strains showed 99.9 % 16S rRNA gene sequence similarity. Cells were Gram-negative, motile rods containing type I methanotroph intracytoplasmic membranes. Colonies and liquid cultures appeared white to pale pink. The pmoA gene encoding particulate methane monooxygenase (pMMO) and the nifH gene encoding nitrogenase were present. Soluble methane monooxygenase (sMMO) activity, the presence of the mmoX gene encoding sMMO and the presence of the pxmA gene encoding a sequence-divergent pMMO were not detected. Methane and methanol were utilized as sole carbon sources. The strains grew optimally at 20 °C (range 15–28 °C) and at pH 6.8–7.3 (range pH 6.3–7.8). The strains grew in media supplemented with up to 1.2 % NaCl. The major cellular fatty acids were C16 : 1ω8c, C16 : 1ω5c, C16 : 1ω7c, C14 : 0, C15 : 0 and C16 : 0 and the DNA G+C content was 47 mol%. 16S rRNA gene- and pmoA-based phylogenetic analyses showed that the isolates cluster among members of the genus Methylomonas within the class Gammaproteobacteria , with pairwise 16S rRNA gene sequence similarities of 97.5 and 97.2 % between R-45377T and the closest related type strains, Methylomonas scandinavica SR5T and Methylomonas paludis MG30T, respectively. Based on phenotypic characterization of strains R-45377T and R-45370, their low 16S rRNA gene sequence similarities and the formation of a separate phylogenetic lineage compared with existing species of the genus Methylomonas , we propose to classify these strains in a novel species, Methylomonas lenta sp. nov., with R-45377T ( = LMG 26260T = JCM 19378T) as the type strain.

A Gram-stain-negative, aerobic, motile, rod-shaped bacterium, designated strain KIS83-12T, was isolated from soil of Gaui island in the Taean region of South Korea. The strain grew at 15–33 °C (optimum, 28 °C), at pH 5.0–8.0 (optimum, pH 7.0). Growth did not occur in the presence of NaCl. The strain was catalase-negative and oxidase-positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that KIS83-12T was most closely related to Solimonas soli DCY12T (96.9 %), Solimonas variicoloris MN28T (96.5 %), Solimonas flava CW-KD 4T (96.5 %) and Solimonas aquatica NAA16T (96.0 %), and formed a robust phyletic lineage with members of the genus Solimonas . The main isoprenoid quinone was Q-8. Major polar lipids included phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Fatty acids present in large and moderate amounts (>5.0 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0, C16 : 1ω5c, summed feature 2 (iso-C16 : 1 I and/or C14 : 0 3-OH) and C12 : 0. The DNA G+C content was 67.9 mol%. On the basis of the taxonomic data obtained in this study, KIS83-12T represents a novel species of the genus Solimonas , for which the name Solimonas terrae sp. nov. is proposed, with KIS83-12T ( = KACC 16967T = DSM 27281T) as the type strain.

A Gram-staining-negative, aerobic, rod-shaped bacterium, designated strain T202T, was isolated from the gill of a cultured flounder (Paralichthys olivaceus). Based on 16S rRNA gene sequence similarity, strain T202T was a member of the family Colwelliaceae and shared 93.32–96.58 % similarity with type strains of all members of the most closely related genus Thalassomonas . Phylogenetically, the isolate shared a root with the type strains of four marine species, Thalassomonas agariperforans M-M1T, Thalassomonas agarivorans TMA1T, Thalassomonas loyana CBMAI 722T and Thalassomonas ganghwensis JC2041T. Optimal growth occurred in the presence of 2–4 % (w/v) NaCl, at pH 7.0–8.0 and at 28 °C. Ubiquinone 8 (Q-8) was the predominant respiratory quinone. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 1ω9c and C17 : 1ω8c. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain T202T was 37 mol%. On the basis of polyphasic analysis, especially the phylogenetic relationships and the lower DNA G+C content, strain T202T is considered to represent a novel species in a new genus, for which the name Thalassotalea piscium gen. nov., sp. nov. is proposed. The type strain of Thalassotalea piscium is T202T ( = JCM 18590T = DSM 26287T = KCTC 32144T). Because Thalassomonas agariperforans M-M1T, Thalassomonas agarivorans TMA1T, Thalassomonas loyana CBMAI 722T and Thalassomonas ganghwensis JC2041T formed a phylogenetic group together with strain T202T that was clearly separated from other known strains of Thalassomonas , these four species are reclassified as members of the genus Thalassotalea as Thalassotalea agariperforans comb. nov. (type strain M-M1T = KCTC 23343T = CCUG 60020T), Thalassotalea agarivorans comb. nov. (type strain TMA1T = BCRC 17492T = JCM 13379T = DSM 19706T), Thalassotalea loyana comb. nov. (type strain CBMAI 722T = LMG 22536T) and Thalassotalea ganghwensis comb. nov. (type strain JC2041T = IMSNU 14005T = KCTC 12041T = DSM 15355T). The type species of the genus Thalassotalea is Thalassotalea ganghwensis gen. nov., comb. nov. An emended description of the genus Thalassomonas is also proposed.

A Gram-stain-negative, aerobic, oxidase- and catalase-positive, flagellated, rod-shaped bacterial strain, designated SM1222T, was isolated from the deep-sea sediment of the South China Sea. The strain grew at 4–35 °C and with 0.5–8 % NaCl (w/v). Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain SM1222T was affiliated with the genus Oceanisphaera in the class Gammaproteobacteria . It shared the highest sequence similarity with the type strain of Oceanisphaera ostreae (96.8 %) and 95.4–96.6 % sequence similarities with type strains of other species of the genus Oceanisphaera with validly published names. Strain SM1222T contained summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C18 : 1ω7c, C16 : 0, C12 : 0 and summed feature 2 (C14 : 0 3-OH and/or iso-C16 : 1 I) as the major fatty acids and ubiquinone Q-8 as the predominant respiratory quinone. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The genomic DNA G+C content of strain SM1222T was 51.5 mol%. On the basis of the evidence presented in this study, strain SM1222T represents a novel species of the genus Oceanisphaera , for which the name Oceanisphaera profunda sp. nov. is proposed. The type strain of Oceanisphaera profunda is SM1222T ( = CCTCC AB 2013241T = KCTC 32510T). An emended description of the genus Oceanisphaera Romanenko et al. 2003 emend. Choi et al. 2011 is also proposed.

A Gram-negative bacterium, strain CZ-AM5T, was isolated from an aerated biological filter in a marine recirculating aquaculture system in Tianjin, China. Its taxonomic position was investigated by using a polyphasic approach. Cells of strain CZ-AM5T were non-spore-forming rods, 0.5–0.8 µm wide and 1.2–2.0 µm long, and motile by means of one or two polar or lateral flagella. Strain CZ-AM5T was strictly aerobic, heterotrophic, oxidase-negative and catalase-positive. Growth occurred at 15–40 °C (optimum, 30–35 °C), at pH 6.5–10.5 (optimum, pH 7.0–7.5) and in the presence of 0–12.0 % (w/v) NaCl (optimum, 4.0 %). The predominant fatty acid was C18 : 1ω7c (80.3 %). Ubiquinone 10 (Q-10) was the sole respiratory quinone. The polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unknown aminolipid, an unknown phospholipid and three unknown lipids. The DNA G+C content was 60.4 mol%. Strain CZ-AM5T showed the highest 16S rRNA gene sequence similarity (96.5 %) to Phaeobacter caeruleus LMG 24369T; it exhibited 16S rRNA gene sequence similarity of 95.0–96.5, 95.2–96.3, 96.2, 94.6–95.7 and 94.8–95.8 % to members of the genera Phaeobacter , Ruegeria , Citreimonas , Leisingera and Donghicola , respectively. However, phylogenetic trees based on 16S rRNA gene sequences showed that strain CZ-AM5T did not join any of the above genera, but formed a distinct lineage in the trees. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain CZ-AM5T is considered to represent a novel genus and species of the family Rhodobacteraceae , for which the name Cribrihabitans marinus gen. nov., sp. nov. is proposed. The type strain of Cribrihabitans marinus is CZ-AM5T ( = CGMCC 1.13219T = JCM 19401T).

A Gram-staining-negative, strictly aerobic, white-colony-forming bacterium, designated strain 5-10T, was isolated from forest soil of Bac Kan Province in Vietnam. Cells were non-motile rods or coccoids, showing oxidase- and catalase-positive reactions. Growth was observed at 10–37 °C (optimum, 30 °C), at pH 5.0–9.0 (optimum, pH 7.0) and in the presence of 0–1.0 % (w/v) NaCl (optimum, 0–0.5 %). The major cellular fatty acids were summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0, C10 : 0 3-OH and summed feature 8 (comprising C18 : 1ω6c and/or C18 : 1ω7c). The G+C content of the genomic DNA was 69.9 mol% and the only respiratory quinone detected was ubiquinone 8 (Q-8). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 5-10T formed a tight phyletic lineage with members of the genus Ramlibacter . Strain 5-10T was most closely related to Ramlibacter tataouinensis TTB310T (97.3 %), but the DNA–DNA relatedness level between the two strains was 38.2±1.8 %. Based on phenotypic, chemotaxonomic and molecular features, strain 5-10T was shown to represent a novel species of the genus Ramlibacter , for which the name Ramlibacter solisilvae sp. nov. is proposed. The type strain is 5-10T ( = KACC 17567T = JCM 19319T). An emended description of the genus Ramlibacter is also proposed.

A Gram-staining-negative, non-motile, non-pigmented and rod-shaped bacterial strain, designated IMCC12053T, was isolated from coastal surface seawater of the Yellow Sea, Korea. Optimal growth of strain IMCC12053T was observed at 30 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. 16S rRNA gene sequence comparisons showed that strain IMCC12053T was most closely related to Celeribacter baekdonensis L-6T (97.5 % similarity) and Celeribacter neptunius H 14T (96.0 %). Strain IMCC12053T formed a robust phylogenetic clade with members of the genus Celeribacter . The DNA–DNA relatedness value between IMCC12053T and C. baekdonensis was far lower than 70 % (35.7–42.5 %), which indicated that strain IMCC12053T is a novel genomic species of the genus Celeribacter . The major respiratory isoprenoid quinone was ubiquinone-10 (Q-10) and major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and aminolipids. The DNA G+C content was 61.0 mol%. On the basis of genotypic and phenotypic data collected in this study, it is proposed that strain IMCC12053T represents a novel species of the genus Celeribacter , for which the name Celeribacter marinus sp. nov. is proposed. The type strain is IMCC12053T ( = KACC 17482T = NBRC 109702T).

Strain AIST, an aerobic halophilic, Gram-reaction-negative, heterotrophic bacterium isolated from the water of Shira Lake in Khakasia, southern Siberia, was characterized using a polyphasic approach. Our analysis of the 16S rRNA gene sequences showed that ‘Aliidiomarina haloalkalitolerans’, ‘Aliidiomarina sanyensis’, Idiomarina maris and AIST formed a distinct lineage. The sequence similarities between AIST and the type strains of species of the genera Idiomarina and Aliidiomarina were 91.6–95.1 % and 94.0–96.9 %, respectively. The major isoprenoid quinone of AIST was ubiquinone 8 (Q-8). Predominant cellular fatty acids were iso-C17 : 0, iso-C15 : 0 and summed feature 9. The genomic DNA G+C content was 45.8 mol%. It is concluded that AIST represents a novel species of the genus Aliidiomarina , and the name Aliidiomarina shirensis sp. nov. is herein proposed for it. The type strain is AIST ( = JCM 17761T = BCRC 80327T). Based on its fatty acid profile and our phylogenetic analysis, we propose that Idiomarina maris be transferred to the genus Aliidiomarina .

The genus Rhizorhapis gen. nov. (to replace the illegitimate genus name Rhizomonas ) is proposed for strains of Gram-negative bacteria causing corky root of lettuce, a widespread and important lettuce disease worldwide. Only one species of the genus Rhizomonas was described, Rhizomonas suberifaciens , which was subsequently reclassified as Sphingomonas suberifaciens based on 16S rRNA gene sequences and the presence of sphingoglycolipid in the cell envelope. However, the genus Sphingomonas is so diverse that further reclassification was deemed necessary. Twenty new Rhizorhapis gen. nov.- and Sphingomonas -like isolates were obtained from lettuce or sow thistle roots, or from soil using lettuce seedlings as bait. These and previously reported isolates were characterized in a polyphasic study including 16S rRNA gene sequencing, DNA–DNA hybridization, DNA G+C content, whole-cell fatty acid composition, morphology, substrate oxidation, temperature and pH sensitivity, and pathogenicity to lettuce. The isolates causing lettuce corky root belonged to the genera Rhizorhapis gen. nov., Sphingobium , Sphingopyxis and Rhizorhabdus gen. nov. More specifically, we propose to reclassify Rhizomonas suberifaciens as Rhizorhapis suberifaciens gen. nov., comb. nov. (type strain, CA1T = LMG 17323T = ATCC 49355T), and also propose the novel species Sphingobium xanthum sp. nov., Sphingobium mellinum sp. nov. and Rhizorhabdus argentea gen. nov., sp. nov. with the type strains NL9T ( = LMG 12560T = ATCC 51296T), WI4T ( = LMG 11032T = ATCC 51292T) and SP1T ( = LMG 12581T = ATCC 51289T), respectively. Several strains isolated from lettuce roots belonged to the genus Sphingomonas , but none of them were pathogenic.

Two strains (J3-AN59T and J3-N84) of Gram-stain-negative, aerobic and rod-shaped bacteria were isolated from the roots of fresh rice plants. The 16S rRNA gene sequence similarity results showed that the similarity between strains J3-AN59T and J3-N84 was 100 %. Both strains were phylogenetically related to members of the genus Rhizobium , and they were most closely related to Rhizobium tarimense ACCC 06128T (97.43 %). Similarities in the sequences of housekeeping genes between strains J3-AN59T and J3-N84 and those of recognized species of the genus Rhizobium were less than 90 %. The polar lipid profiles of both strains were predominantly composed of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unknown aminophospholipid. The major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The DNA G+C contents of J3-AN59T and J3-N84 were 55.7 and 57.1 mol%, respectively. The DNA–DNA relatedness value between J3-AN59T and J3-N84 was 89 %, and strain J3-AN59T showed 9 % DNA–DNA relatedness to R. tarimense ACCC 06128T, the most closely related strain. Based on this evidence, we found that J3-AN59T and J3-N84 represent a novel species in the genus Rhizobium and we propose the name Rhizobium rhizoryzae sp. nov. The type strain is J3-AN59T ( = ACCC 05916T = KCTC 23652T).