Description of Rhodobacter azollae sp. nov. and Rhodobacter lacus sp. nov.

Abstract

Three strains (JA826T, JA912T and JA913), which were yellowish brown colour, rod to oval shaped, Gram-stain-negative, motile, phototrophic bacteria with a vesicular architecture of intracytoplasmic membranes, were isolated from different pond samples. The DNA G+C content of the three strains was between 64.6 and 65.5 mol%. The highest 16S rRNA gene sequence similarity of all three strains was with the type strains of the genus Rhodobacter sensu stricto in the family Rhodobacteraceae. Strain JA826T had highest sequence similarity with Rhodobacter maris JA276T (98.5 %), Rhodobacter viridis JA737T (97.5 %) and other members of the genus Rhodobacter (<97 %). Strain JA912T had highest sequence similarity with Rhodobacter viridis JA737T (99.6 %), Rhodobacter sediminis N1T (99.3 %), Rhodobacter capsulatus ATCC 11166T (98.8 %) and less than 97 % similarity with other members of the genus Rhodobacter. The 16S rRNA gene sequence similarity between strains JA826T and JA912T was 96.9 %. DNA-DNA hybridization showed that strains JA826T and JA912T (values among themselves and between the type strains of nearest members <44 %) did not belong to any of the nearest species of the genus Rhodobacter. However, strains JA912T and JA913 were closely related (DNA-DNA hybridization value >90 %). The genomic distinction was also supported by differences in phenotypic and chemotaxonomic characteristics in order to propose strains JA826T (=KCTC 15478T=LMG 28758T) and JA912T (=KCTC 15475T=LMG 28748T) as new species in the genus Rhodobacter sensu stricto with the names Rhodobacter lacus and Rhodobacter azollae, respectively.

First report on Bacterial Diversity of Potable Spring water of Indian Himalayan Region

“…Some of the important Rhodobacter sp . identified from aquatic environment are Rhodobacter adriaticus isolated from Adriatic Sea (IMHOFF et al ., 1984) ; Rhodovulum aestuarii isolated from brackish water collected from an estuary (Ramana et al ., 2016); Rhodobacter azollae and Rhodobacter lacus isolated from different pond samples of Kukatpally, India (Suresh et al ., 2017); Rhodobacter vinaykumarii a marine phototrophic alpha-proteobacterium from tidal waters in Visakhapatnam, on the east coast of India (Srinivas et al ., 2007). There are also reports from Himalayan regions viz.…”

Taxogenomics Resolves Conflict in the Genus Rhodobacter: A Two and Half Decades Pending Thought to Reclassify the Genus Rhodobacter

“…azollae, Rba. lacus (Suresh et al, 2017) and Rba. sediminis (Subhash and Lee, 2016) are not available.…”

“…Species of the genus Rhodobacter have ovoid to rod-shaped-cells, are Gram-stain negative, facultative photoheterotrophic and have vesicular/lamellar ICM architecture, bacteriochlorophyll- a , carotenoids of the spheroidene series and have Q10 as their major quinone. Some of the members are capable of growing photolithoautotrophically in the presence of sulfide/H 2 as an electron donor (Imhoff, 2005; Girija et al, 2010; Suresh et al, 2017; Gandham et al, 2018).…”

“…Based on 16S rRNA gene sequence phylogenetic analysis we previously demonstrated the heterogeneity of the genus Rhodobacter , due to a large diversity of interspersing chemotrophs dividing the members into five monophyletic clusters (Suresh et al, 2017). Apart from being polyphyletic, the members of the genus Rhodobacter also have phenotypic differences which mainly include: heterogeneity in polar lipids (presence and absence glycolipids/diphosphatidylglycerol [DPG]), ICM architecture (vesicular/lamellar), sulfur metabolism and cell division (budding/binary fission).…”

Phenotypic identification and numerical taxonomy of pigmented bacteria isolated from marine and freshwater aquatic at Yogyakarta, Indonesia

“…Tests were performed with strains grown at constant light at 10 -15 µmol photons m -2 s -1 or with strains grown in the dark. Catalase production, nitrate reduction, methylene blue reduction nitrite of the strains were determined by standard methods reported previously [14]. The ability to tetracycline resistance was investigated by using an agar surface plate method in which PPES II and NB were used.…”