Rhodomicrobium udaipurense sp. nov., a psychrotolerant, phototrophic alphaproteobacterium isolated from a freshwater stream.

Two strains (JA643(T) and JA755) of Gram-stain-negative, facultatively anaerobic phototrophic, bacteria capable of growth at low temperatures (10-15 °C) were isolated from freshwater streams from different geographical regions of India. Both strains contain bacteriochlorophyll a and carotenoids of the spirilloxanthin series. Phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified phospholipid (PL), unidentified amino lipids (AL1-AL6, AL9) and an unidentified lipid (L1) were the polar lipids present in both strains. The major cellular fatty acid was C18 : 1ω7c (76-79 % of the total). Bacteriohopane derivatives (BHD1,2), unidentified hopanoids (UH1-5), diplopterol (DPL) and diploptene (DPE) were the major hopanoids of both strains. The DNA G+C content was 64.2-64.5 mol%. 16S rRNA gene sequence-based phylogenetic analysis showed that both strains are closely related to the genus Rhodomicrobium and clustered with Rhodomicrobium vannielii DSM 162(T) (99 % sequence similarity). However, both strains exhibited only 46.1 % DNA-DNA hybridization with R. vannielii DSM 162(T). Strains JA643(T) and JA755 shared >99 % 16S rRNA gene sequence similarity and were >85 % related on the basis of DNA-DNA hybridization; they are therefore considered to represent a novel species in the genus Rhodomicrobium, for which the name Rhodomicrobium udaipurense sp. nov. is proposed. The type strain is JA643(T) ( = KCTC 15219(T) = NBRC 109057(T)).

Chryseomicrobium amylolyticum sp. nov., isolated from a semi-arid tropical soil, and emended descriptions of the genus Chryseomicrobium and Chryseomicrobium imtechense.

A rod-shaped, non-motile, Gram-stain-positive, catalase-positive, starch-hydrolysing strain, JC16(T), was isolated from a semi-arid tropical soil from India. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain JC16(T) clustered with the type species of the genus Chryseomicrobium, Chryseomicrobium imtechense MW 10(T), a member of the family Planococcaceae within the phylum Firmicutes with 99.3 % sequence similarity. Major (>10 %) fatty acids of strain JC16(T) were iso-C15 : 0 and iso-C16 : 0. Minor (<10 and >1 %) amounts of C16 : 0, iso-C14 : 0, anteiso-C15 : 0, iso-C17 : 0, anteiso-C17 : 0, iso-C17 : 1ω10c and C16 : 1ω11c are present in strain JC16(T). Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phospholipids (PL2-4), aminolipids (AL1, 2) and an unknown lipid. Cell wall peptidoglycan was of the type l-Orn-D-Glu. The quinone system was composed of MK-7, MK-8 and MK-6. Genomic DNA G+C content of strain JC16(T) was 57.6 mol%. Distinct physiological, chemotaxonomic and genotypic differences (37 % reassociation based on DNA-DNA hybridization) from Chryseomicrobium imtechense MW 10(T) support the classification of strain JC16(T) as a representative of a novel species in the genus Chryseomicobium, for which the name Chryseomicrobium amylolyticum sp. nov. (type strain JC16(T) = DSM 23442(T) = NBRC 105215(T)) is proposed.

Rhodobacter viridis sp. nov., a phototrophic bacterium isolated from mud of a stream.

A green phototrophic bacterium (strain JA737(T)), which was oval- to rod-shaped, Gram-negative and motile, was isolated from mud of a stream in the Western Ghats of India. Strain JA737(T) contained bacteriochlorophyll a, and the major carotenoid was neurosporene. The major quinone was Q-10 and the polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid, two unidentified phospholipids and five unidentified lipids. Phylogenetic analysis showed that the strain clustered with members of the genus Rhodobacter belonging to the family Rhodobacteraceae of the class Alphaproteobacteria. Based on 16S rRNA gene sequence analysis, strain JA737(T) had highest sequence similarity with Rhodobacter capsulatus ATCC 11166(T) (98.8 %), Rhodobacter maris JA276(T) (97 %), Rhodobacter aestuarii JA296(T) (96.7 %) and other members of the genus Rhodobacter (<96 %). However, strain JA737(T) showed 22-55 % DNA-DNA relatedness with the above type strains. On the basis of phenotypic, chemotaxonomic and molecular genetic evidence, strain JA737(T) represents a novel species of the genus Rhodobacter, for which the name Rhodobacter viridis sp. nov. is proposed. The type strain is JA737(T) ( = KCTC 15167(T) = MTCC 11105(T) = NBRC 108864(T)).

Descriptions of Rhodopseudomonas parapalustris sp. nov., Rhodopseudomonas harwoodiae sp. nov. and Rhodopseudomonas pseudopalustris sp. nov., and emended description of Rhodopseudomonas palustris.

Four strains (JA310(T), JA531(T), JA447 and JA490) of red to reddish brown pigmented, rod-shaped, motile and budding phototrophic bacteria were isolated from soil and freshwater sediment samples from different geographical regions of India. All strains contained bacteriochlorophyll a and carotenoids of the spirilloxanthin series. The major cellular fatty acid of strains JA310(T) and JA531(T) was C(18:1)ω7c, the quinone was Q-10 and polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an aminohopanoid and an unidentified aminolipid. Phylogenetic analysis based on 16S rRNA gene sequences showed that all strains clustered with species of the genus Rhodopseudomonas in the class Alphaproteobacteria. Strains JA531(T), JA447 and JA490 were genotypically (>80% related based on DNA-DNA hybridization) and phenotypically closely related to each other and the three strains were distinct from strain JA310(T) (33% related). Furthermore, all four strains had less than 48% relatedness (DNA-DNA hybridization) with type strains of members of the genus Rhodopseudomonas, i.e. Rhodopseudomonas palustris ATCC 17001(T), Rhodopseudomonas faecalis JCM 11668(T) and Rhodopseudomonas rhenobacensis DSM 12706(T). The genomic DNA G+C contents of strains JA310(T) and JA531(T) were 63.8 and 62.4 mol%, respectively. On the basis of phenotypic, chemotaxonomic and molecular genetic evidence, it is proposed that strains JA310(T) ( = NBRC 106083(T) = KCTC 5839(T)) and JA531(T) ( = NBRC 107575(T) = KCTC 5841(T)) be classified as the type strains of two novel species of the genus Rhodopseudomonas, Rhodopseudomonas parapalustris sp. nov. and Rhodopseudomonas harwoodiae sp. nov., respectively. In addition, we propose that strain DSM 123(T) ( = NBRC 100419(T)) represents a novel species, Rhodopseudomonas pseudopalustris sp. nov., since this strain differs genotypically and phenotypically from R. palustris ATCC 17001(T) and other members of the genus Rhodopseudomonas. An emended description of R. palustris is also provided.

Phaeospirillum tilakii sp. nov., a phototrophic alphaproteobacterium isolated from aquatic sediments.

Two strains (JA492(T) and JA590) of spiral-shaped, anaerobic, Gram-stain-negative, motile, purple non-sulfur bacteria were isolated from aquatic sediments from a bird sanctuary and a stream, respectively, and were characterized by a polyphasic taxonomic approach. Bacteriochlorophyll a and carotenoids (rhodopin, lycopene, hydroxylycopene glucoside and dihydroxylycopene diglucoside) were present as photosynthetic pigments. Intracellular photosynthetic membranes were of the stacked type. The major fatty acids were C(18 : 1)ω7c, C(16 : 0) and summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c) in both strains. Ubiquinones and menaquinones were present as major quinone components. The genomic DNA G+C contents of strains JA492(T) and JA590 were 63.8 and 61.5 mol%, respectively. Both strains were closely related (mean DNA-DNA hybridization >70 %). Phylogenetic analysis showed that the strains clustered with species of the genus Phaeospirillum of the family Rhodospirillaceae, class Alphaproteobacteria. Based on 16S rRNA gene sequence analysis, both strains showed highest sequence similarity with Phaeospirillum oryzae JA317(T) (97.2-97.4 %), Phaeospirillum molischianum DSM 120(T) (96.5-96.7 %), Phaeospirillum fulvum DSM 113(T) (96.7-96.9 %) and Phaeospirillum chandramohanii JA145(T) (96.5-96.7 %). DNA-DNA relatedness between strain JA492(T) and its closest relative in the genus Phaeospirillum was less than 42 %. It is evident from phenotypic, chemotaxonomic and molecular genetic data that strain JA492(T) represents a novel species of the genus Phaeospirillum, for which the name Phaeospirillum tilakii sp. nov. is proposed; the type strain is JA492(T) ( = NBRC 107650(T) = KCTC 15012(T)).