A type strain was isolated from glacier sediment sample collected from the Queen Maud Land, Antarctica, during the 38th Indian Scientific Expedition to Antarctica in 2019. The strain is named as Marisediminicola senii in the honor of late Mr. Subhajit Sen, a researcher from India who lost his life in an accident during the 37th Indian Scientific Expedition to Antarctica in 2017. Mr. Sen’s research in Antarctica was focused on fabric analysis of glacial deposits.
Cells of the isolated strain are Gram-stain-variable, aerobic, cocci shaped with sizes of 0.2–0.3µm in diameter. Strain is catalase positive and oxidase-negative. Colonies formed on Zobell marine agar are orange, raised, circular, translucent and ~3mm in diameter after incubation for 7 days at 20°C. Nitrate and nitrite are not reduced by the strain. Strain was negative for indole production, H2S production and could not hydrolyze urea and gelatin. However, strain hydrolyses aesculin. Strain shows positive result for 4-nitrophenyl-β-d-galactopyranoside while negative for l-tryptophan, d-glucose, l-arginine, d-glucose, l-arabinose, d-mannose, d-mannitol, N-acetyl-glucosamine, maltose, potassium gluconate, capric acid, adipic acid, malic acid, trisodium citrate, phenylacetic acid. Only d-glucose, methyl-α-d-mannopyranoside were utilized as carbon sources. Strain is positive for esterase, esterase lipase, leucine arylamidase and valine arylamidase and weakly positive for cysteine arylamidase. Strain consists of diphosphatidylglycerol and phosphatidylglycerol as major polar lipids.
Phylogenetic analysis based on 16S rRNA gene sequences revealed highest sequence similarity of the strain with Marisediminicola antarctica ,demonstrated distinct phylogenetic positioning of strain within the genus Marisediminicola. Distinguishing characteristics based on the polyphasic analysis indicated the strain as a novel species of genus Marisediminicola for which the name Marisediminicola senii sp. nov., is proposed.