Marichromatium litoris sp. nov. and Marichromatium chrysaorae sp. nov. isolated from beach sand and from a jelly fish (Chrysaora colorata)

Rhodomicrobium lacus sp. nov., an alkalitolerent bacterium isolated from Umiam lake, Shillong, India

A Gram-stain-negative, motile, alkali-tolerant, swollen-rod shaped, reddish brown coloured, phototrophic bacterium designated as strain JA980^T, was isolated from freshwater sampled at Umiam lake, Shillong, India. Strain JA980^T grew well up to pH 9.0. Respiratory quinones were ubiquinone 10 and rhodoquinone 10. The major fatty acid was C_{18: 1}ω7c/C_18:1ω6c with minor amounts of C_18:0, C_16:0, C_18:0 3-OH and C_16:0 3-OH. Strain JA980^T contained bacteriochlorophyll-a and carotenoids of the spirilloxanthin series. The polar lipids of strain JA980^T comprised phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol, an unidentified phospholipid, unidentified amino lipids (AL1,3,4,5) and an unidentified lipid (L1). Strain JA980^T had the highest (99.57 %) 16S rRNA gene sequence similarity to the type strains of Rhodomicrobium vannielii ATCC17100^T and Rhodomicrobium udaipurense JA643^T. The genome of strain JA980^T was 3.88 Mbp with a DNA G+C content of 62.4 mol%. Based on the results of phylogenetic analyses, low in silico DNA-DNA hybridization values (33 %), low (87 %) average nucleotide identity results, chemotaxonomic characteristics and differential physiological properties, strain JA980^T could not be classified into either of the two recognized species of the genus Rhodomicrobium, suggesting that it represents a novel species, for which the name Rhodomicrobium lacus sp. nov. is proposed. The type strain is JA980^T (=KCTC 15697^T= MCC 3714^T= NBRC 113803^T).

Draft Genome Sequences of Two Closely Related Marichromatium Isolates, Photosynthetic Gammaproteobacteria from Marine Ecosystems

Marichromatium species are photosynthetic gammaproteobacteria found in marine environments. Only two Marichromatium genomes are publicly available.

Thiorhodococcus fuscus sp. nov., isolated from a lagoon

A brown, moderately halophilic, photoautotrophic bacterium designated strain JA363T was purified from a photoheterotrophic enrichment obtained from sediment from Chilika lagoon, Odisha, India. Cells of the isolate were coccoid, motile by means of single polar flagellum and Gram-stain-negative. Strain JA363T had an obligate requirement for NaCl and could tolerate up to 7 % (w/v) NaCl. Strain JA363T had complex growth factor requirements. Internal photosynthetic membranes were present as vesicles. Strain JA363T contained bacteriochlorophyll a and spirilloxanthin series carotenoids with rhodopin as a major (>85 %) component. C16 : 1ω7c/C16 : 1ω6c, C18 : 1ω7c and C16 : 0 were the major fatty acids and phosphatidylglycerol and phosphatidylethanolamine were the major polar lipids. Q8 was the predominant quinone system of strain JA363T. The DNA G+C content was 64 mol%. The highest 16S rRNA gene sequence similarity of strain JA363T was found with the type strains of Thiorhodococcus kakinadensis (98.7 %), Thiohalobacter thiocyanaticus (98.2 %), Thiophaeococcus fuscus (97.4 %) and Thiorhodococcus bheemlicus (96.3 %). However, the phylogenetic trees generated firmly placed strain JA363T in the genus Thiorhodococcus, which was further supported by phenotypic and chemotaxonomic evidence. Consequently, strain JA363T is described as representing a novel species of the genus Thiorhodococcus as Thiorhodococcus fuscus sp. nov. The type strain is JA363T ( = KCTC 5701T = NBRC 104959T).

Thiophaeococcus fuscus sp. nov., isolated from a lagoon

A brown-coloured bacterium, designated strain JA633(T), was purified from a photoheterotrophic enrichment culture obtained from black sand of a lagoon. Cells of strain JA633(T) were coccoid-spherical, Gram-stain-negative and motile by means of polar flagella. Strain JA633(T) had an obligate requirement for NaCl and could tolerate up to 4% (w/v) NaCl. Internal photosynthetic membranes were present as vesicles. Photo-organoheterotrophy was the only growth mode observed. Strain JA633(T) contained bacteriochlorophyll a and a major (>85%) unidentified carotenoid of the spirilloxanthin series. Thiamine and p-aminobenzoic acid were required for growth. Major fatty acids were C(18 : 1)ω7c/C(18 : 1)ω6c, C(16 : 0) and C(16 : 1)ω7c/C(16 : 1)ω6c. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphotidylcholine and an unknown aminophospholipid were the major polar lipids in strain JA633(T). The DNA G+C content of strain JA633(T) was 64.5 mol%. Strain JA633(T) shared highest 16S rRNA gene sequence similarity with the type strains of Thiorhodococcus kakinadensis (96.9%), Thiophaeococcus mangrovi (96.3%) and Thiorhodococcus bheemlicus (96.2%), which belonged to the class Gammaproteobacteria. However, phylogenetic analysis based on 16S rRNA gene sequences showed that strain JA633(T) formed a separate clade along with Thiophaeococcus mangrovi JA304(T) whereas the members of the genus Thiorhodococcus remained as two distinct phylogenetic lineages. Based on morphological, physiological, chemotaxonomic and molecular evidence, strain JA633(T) was significantly different from the type strain of Thiophaeococcus mangrovi of the family Chromatiaceae. It is thus proposed that the strain be classified as a representative of a novel species, for which the name Thiophaeococcus fuscus sp. nov. is proposed. The type strain is JA633(T) ( = KCTC 15337(T) = NBRC 109958(T)).

MLSA barcoding of Marichromatium spp. and reclassification of Marichromatium fluminis (Sucharita et al., 2010) as Phaeochromatium fluminis gen. nov. comb. nov

Thirty-one members of the genus Marichromatium were analysed based on multilocus sequence analysis (MLSA) of four concatenated protein-coding genes (fusA, pufM, dnaK, recA) along with the internal transcribed spacer (ITS; 16S-23S rRNA) region and 16S rRNA gene. The restriction patterns obtained from the in silico analysis of the concatenated sequences were good barcodes for the identification of Marichromatium spp. Distinct phenotypic, chemotaxonomic and molecular differences allowed the separation of Marichromatium fluminis JA418(T) into a new genus in the family Chromatiaceae, for which we propose the name Phaeochromatium fluminis gen. nov. comb. nov.