title: Selenihalanaerobacter shriftii gen. nov., sp. nov., a halophilic anaerobe from Dead Sea sediments that respires selenate.
abstract: We isolated an obligately anaerobic halophilic bacterium from the Dead Sea that grew by respiration of selenate. The isolate, designated strain DSSe-1, was a gram-negative, non-motile rod. It oxidized glycerol or glucose to acetate + CO2 with concomitant reduction of selenate to selenite plus elemental selenium. Other electron acceptors that supported anaerobic growth on glycerol were nitrate and trimethylamine-N-oxide; nitrite, arsenate, fumarate, dimethylsulfoxide, thiosulfate, elemental sulfur, sulfite or sulfate could not serve as electron acceptors. Growth on glycerol in the presence of nitrate occurred over a salinity range from 100 to 240 g/l, with an optimum at 210 g/l. Analysis of the 16S rRNA gene sequence suggests that strain DSSe-1 belongs to the order Halanaerobiales, an order of halophilic anaerobes with a fermentative or homoacetogenic metabolism, in which anaerobic respiratory metabolism has never been documented. The highest 16S rRNA sequence similarity (90%) was found with Acetohalobium arabaticum (X89077). On the basis of physiological properties as well as the relatively low homology of 16S rRNA from strain DSSe-1 with known genera, classification in a new genus within the order Halanaerobiales, family Halobacteroidaceae is warranted. We propose the name Selenihalanaerobacter shriftii. Type strain is strain DSSe-1 (ATCC accession number BAA-73).
authors.affiliation: US Geological Survey, 345 Middlefield Road, ms 480, Menlo Park, CA 94025, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Blum
authors.forename: J F
authors.initials: JF
authors.lastname: Stolz
authors.forename: A
authors.initials: A
authors.lastname: Oren
authors.forename: R S
authors.initials: RS
authors.lastname: Oremland
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019015:Geologic Sediments; D010802:Phylogeny; D064586:Selenic Acid; D018036:Selenium Compounds / Q000378:metabolism*
chemical_list: D018036:Selenium Compounds; D064586:Selenic Acid