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A gram-positive, motile, strict anaerobic spore-forming bacterium was isolated from the over-cooled brine in the permafrost. The optimal temperature for isolate growth was 5-6 degrees C at pH 6.8-7.2. The bacterium was growing on the medium rich in saccharides and disaccharides. Out of polysaccharides tested, only xylan sustained the growth. Fermentation of the hexoses led to the formation of acetate, butyrate, lactate, H2,CO2 and some formate and ethanol. Cell wall peptidoglycan contained meso-diaminopimelic acid. The major fatty acids of the cell wall were C(14:0) and C(16:1c9). The content of G-C pairs in DNA was 31.4 mol%. As phylogenetic analysis has shown, it is closely linked to the members of cluster 1 of Clostridium. It differs from the other species of the genus by the substrates necessary for the growth, products forming as a result of the fermentation and content of the fatty acids in the cell wall. Thus, it was suggested to describe this strain as a new species named Clostridium algoriphilum. Type strain 14D1 was deposited into the Russian Collection of the Microorganisms VKM B-2271T and German Collection of the Microorganisms DSM 16153T .

A strictly anaerobic, Gram-positive, psychrotolerant, endospore-forming bacterium (strain A121 T ) was isolated from a permafrost sample collected in the Canadian High Arctic. Phylogenetic analysis of the 16S rRNA gene sequence of strain A121T showed its affiliation with the group of psychrophilic and psychrotolerant members of cluster I of the genus Clostridium, Clostridium bowmanii DSM 14206 T being the closest relative (sequence similarity 98.5 %). Levels of DNA-DNA relatedness between strain A121 T and the type strains of phylogenetically related species ranged from 33 to 52 %. Strain A121 T grew in PY broth at temperatures between 4 and 28 6C(optimum 15-20 6C), at pH 6.0-8.0 (optimum pH 6.5-7.2) and in NaCl concentrations of 0-10.0 % (optimum 0-2.0 %). The strain utilized a narrow range of carbohydrates as sources of carbon and energy, including glucose, fructose, trehalose, maltose and starch; it also hydrolysed gelatin. Predominant fatty acids were C 16 : 1 cis9, C 16 : 1 cis9 DMA, C 16 : 0 and C 14 : 0 . The DNA G+C content was 31.5 mol%. On the basis of its overall genotypic and phenotypic characteristics, strain A121 T is classified within a novel species of the genus Clostridium, Clostridium tagluense sp. nov. The type strain is A121 T (5VKM B-2369 T 5DSM 17763 T ).

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