Natronoflexus pectinivorans gen. nov. sp. nov., an obligately anaerobic and alkaliphilic fermentative member of Bacteroidetes from soda lakes

Abstract

Anaerobic enrichment with pectin at pH 10 and moderate salinity inoculated with sediments from soda lakes of the Kulunda Steppe (Altai, Russia) resulted in the isolation of a novel member of the Bacteroidetes, strain AP1T. The cells are long, flexible, Gram-negative rods forming pink carotenoids. The isolate is an obligate anaerobe, fermenting various carbohydrates to acetate and succinate. It can hydrolyze and utilize pectin, xylan, starch, laminarin and pullulan as growth substrates. Growth is possible in a pH range from 8 to 10.5, with an optimum at pH 9.5, and at a salinity range from 0.1 to 2 M Na+. Phylogenetic analysis based on 16S rRNA sequences placed the isolate into the phylum Bacteroidetes as a separate lineage within the family Marinilabilaceae. On the basis of distinct phenotype and phylogeny, the soda lake isolate AP1T is proposed to be assigned in a new genus and species Natronoflexus pectinivorans (=DSM24179T = UNIQEM U807T).Electronic supplementary materialThe online version of this article (doi:10.1007/s00792-011-0399-7) contains supplementary material, which is available to authorized users.

Carboxylicivirga linearis sp. nov., isolated from a sea cucumber culture pond

“…In recent years, many novel species of the family Marinilabiliaceae have been described, which includes, at the time of writing, 10 genera. Seven of these genera, Alkaliflexus , Alkalitalea , Anaerophaga , Mangroviflexus , Marinilabilia , Natronoflexus and Thermophagus , are anaerobic (Zhilina et al , 2004; Zhao et al , 2012; Denger et al , 2002; Suzuki, 2011; Sorokin et al , 2011; Gao et al , 2013); the other three, Geofilum , Saccharicrinis and Carboxylicivirga , described more recently, are facultatively anaerobic. The genus Geofilum was created by Miyazaki et al (2012) following the description of Geofilum rubicundum ; the genus Saccharicrinis was ascertained by reclassification of [ Cytophaga ] fermentans as Saccharicrinis fermentans (Yang et al , 2014); and the genus Carboxylicivirga was created by Yang et al (2014) following description of two novel species, Carboxylicivirga mesophila and Carboxylicivirga taeanensis .…”

Labilibacter aurantiacus gen. nov., sp. nov., isolated from sea squirt (Styela clava) and reclassification of Saccharicrinis marinus as Labilibacter marinus comb. nov.

“…Species in the genera Alkaliflexus, Alkalitalea, Anaerophaga, Mangroviflexus, Natronoflexus and Thermophagus are anaerobic, while species in the genera Geofilum, Marinilabilia, Carboxylicivirga and Saccharicrinis are capable of fermentative metabolism. Members of the family Marinilabiliaceae are Gram-stain-negative rods and contain MK-7 as the respiratory quinone [2][3][4][5][6][7][8][9][10][11][12].…”

On the diversity of fungi from soda soils

“…High densities of bacterial and archaeal blooms may even cause the coloration of water basins associated with the soda soils, for example, as in Magadi Lake (Kenya) due to massive expansion of red haloalkaliphilic Archaea (Jones et al 1998). Studies of 16S rDNA gene sequences revealed a complex phylogenetically heterogeneous structure of the bacterial communities inhabiting soda lakes (Duckworth et al 1996;Rees et al 2004;Dong et al 2006;Wani et al 2006) often with the recovery of many new bacterial species (Sorokin and Muyzer 2010;Sorokin et al 2011;Kompantseva et al 2012;Antony et al 2012). The accumulated data suggest that soda lakes in diverse geographical regions harbor alkaliphilic bacteria and Archaea from all major trophic groups (Rees et al 2004).…”