title: Alkaliflexus imshenetskii gen. nov. sp. nov., a new alkaliphilic gliding carbohydrate-fermenting bacterium with propionate formation from a soda lake.
abstract: Anaerobic saccharolytic bacteria thriving at high pH values were studied in a cellulose-degrading enrichment culture originating from the alkaline lake, Verkhneye Beloye (Central Asia). In situ hybridization of the enrichment culture with 16S rRNA-targeted probes revealed that abundant, long, thin, rod-shaped cells were related to Cytophaga. Bacteria of this type were isolated with cellobiose and five isolates were characterized. Isolates were thin, flexible, gliding rods. They formed a spherical cyst-like structure at one cell end during the late growth phase. The pH range for growth was 7.5-10.2, with an optimum around pH 8.5. Cultures produced a pinkish pigment tentatively identified as a carotenoid. Isolates did not degrade cellulose, indicating that they utilized soluble products formed by so far uncultured hydrolytic cellulose degraders. Besides cellobiose, the isolates utilized other carbohydrates, including xylose, maltose, xylan, starch, and pectin. The main organic fermentation products were propionate, acetate, and succinate. Oxygen, which was not used as electron acceptor, impaired growth. A representative isolate, strain Z-7010, with Marinilabilia salmonicolor as the closest relative, is described as a new genus and species, Alkaliflexus imshenetskii. This is the first cultivated alkaliphilic anaerobic member of the Cytophaga/ Flavobacterium/ Bacteroides phylum.
authors.affiliation: Institute of Microbiology of the Russian Academy of Sciences, Prospect 60-let Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: Tatyana N
authors.initials: TN
authors.lastname: Zhilina
authors.forename: Ramona
authors.initials: R
authors.lastname: Appel
authors.forename: Christina
authors.initials: C
authors.lastname: Probian
authors.forename: Enrique Llobet
authors.initials: EL
authors.lastname: Brossa
authors.forename: Jens
authors.initials: J
authors.lastname: Harder
authors.forename: Friedrich
authors.initials: F
authors.lastname: Widdel
authors.forename: Georgii A
authors.initials: GA
authors.lastname: Zavarzin
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D001208:Asia; D001439:Bacteroides / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification* / Q000502:physiology; D050260:Carbohydrate Metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D005285:Fermentation; D020459:Genes, rRNA; D006863:Hydrogen-Ion Concentration; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D010802:Phylogeny; D010860:Pigments, Biological / Q000096:biosynthesis; D011422:Propionates / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D019802:Succinic Acid / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010860:Pigments, Biological; D011422:Propionates; D012336:RNA, Ribosomal, 16S; D019802:Succinic Acid; C029658:propionic acid; D019342:Acetic Acid