Psychrophilic sulfate-reducing bacteria isolated from permanently cold arctic marine sediments: description of Desulfofrigus oceanense gen. nov., sp. nov., Desulfofrigus fragile sp. nov., Desulfofaba gelida gen. nov., sp. nov., Desulfotalea psychrophila gen. nov., sp. nov. and Desulfotalea arctica s

Five psychrophilic, Gram-negative, sulfate-reducing bacteria were isolated from marine sediments off the coast of Svalbard. All isolates grew at the in situ temperature of -1.7 degrees C. In batch cultures, strain PSv29T had the highest growth rate at 7 degrees C, strains ASv26T and LSv54T had the highest growth rate at 10 degrees C, and strains LSv21T and LSv514T had the highest growth rate at 18 degrees C. The new isolates used the most common fermentation products in marine sediments, such as acetate, propionate, butyrate, lactate and hydrogen, but only strain ASv26T was able to oxidize fatty acids completely to CO2. The new strains had growth optima at neutral pH and marine salt concentration, except for LSv54T which grew fastest with 1% NaCl. Sulfite and thiosulfate were used as electron acceptors by strains ASv26T, PSv29T and LSv54T, and all strains except PSv29T grew with Fe3+ (ferric citrate) as electron acceptor. Chemotaxonomy based on cellular fatty acid patterns and menaquinones showed good agreement with the phylogeny based on 16S rRNA sequences. All strains belonged to the delta subclass of Proteobacteria but had at least 9% evolutionary distance from known sulfate reducers. Due to the phylogenetic and phenotypic differences between the new isolates and their closest relatives, establishment of the new genera Desulfotalea gen. nov., Desulfofaba gen. nov. and Desulfofrigus gen. nov. is proposed, with strain ASv26T as the type strain of the type species Desulfofrigus oceanense sp. nov., LSv21T as the type strain of Desulfofrigus fragile sp. nov., PSv29T as the type strain of the type species Desulfofaba gelida sp. nov., LSv54T as the type strain of the type species Desulfotalea psychrophila sp. nov. and LSv514T as the type strain of Desulfotalea arctica sp. nov.

[1]  R. Kroppenstedt,et al.  Cellular Fatty Acid Composition of Desulfovibrio Species and Its Use in Classification of Sulfate-reducing Bacteria , 1992 .

[2]  W. Whitman,et al.  Precise Measurement of the G+C Content of Deoxyribonucleic Acid by High-Performance Liquid Chromatography , 1989 .

[3]  A. Teske,et al.  Desulforhopalus vacuolatus gen. nov., sp. nov., a new moderately psychrophilic sulfate-reducing bacterium with gas vacuoles isolated from a temperate estuary , 1996, Archives of Microbiology.

[4]  B. Jørgensen,et al.  Effect of temperature on sulphate reduction, growth rate and growth yield in five psychrophilic sulphate-reducing bacteria from Arctic sediments. , 1999, Environmental microbiology.

[5]  D. Schüler,et al.  ISOLATION AND TAXONOMIC CHARACTERIZATION OF A HALOTOLERANT, FACULTATIVELY IRON-REDUCING BACTERIUM. , 1995 .

[6]  D. Christensen.  Determination of substrates oxidized by sulfate reduction in intact cores of marine sediments1 , 1984 .

[7]  N J Russell,et al.  Cold adaptation of microorganisms. , 1990, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[8]  H. Noller,et al.  Gene organization and primary structure of a ribosomal RNA operon from Escherichia coli. , 1981, Journal of molecular biology.

[9]  R. Cord-Ruwisch.  A quick method for the determination of dissolved and precipitated sulfides in cultures of sulfate-reducing bacteria , 1985 .

[10]  B. Tindall.  A comparative study of the lipid composition of Halobacterium saccharovorum from various sources , 1990 .

[11]  R. Rosselló-Móra,et al.  Reclassification of Shewanella putrefaciens Owen's genomic group II as Shewanella baltica sp. nov. , 1998, International journal of systematic bacteriology.

[12]  D. B. Nedwell,et al.  Measurements of Seasonal Rates and Annual Budgets of Organic Carbon Fluxes in an Antarctic Coastal Environment at Signy Island, South Orkney Islands, Suggest a Broad Balance between Production and Decomposition , 1993, Applied and environmental microbiology.

[13]  G. Gibson,et al.  Determination of the Substrates for Sulphate-reducing Bacteria within Marine and Esturaine Sediments with Different Rates of Sulphate Reduction , 1989 .

[14]  D. Stahl,et al.  Comparison of phylogenetic relationships based on phospholipid fatty acid profiles and ribosomal RNA sequence similarities among dissimilatory sulfate-reducing bacteria. , 1994, FEMS microbiology letters.

[15]  D. Canfield,et al.  Benthic mineralization and exchange in Arctic sediments (Svalbard, Norway) , 1998 .

[16]  K. Straub,et al.  Screening for Genetic Diversity of Isolates of Anaerobic Fe(II)-oxidizing Bacteria Using DGGE and Wh , 1997 .

[17]  F. Widdel,et al.  Gram-Negative Mesophilic Sulfate-Reducing Bacteria , 1992 .

[18]  O. Kandler,et al.  International Committee on Systematic Bacteriology: announcement of the report of the ad hoc Committee on Reconciliation of Approaches to Bacterial Systematics. , 1987, Zentralblatt fur Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology.

[19]  R. Murray,et al.  Determinative and cytological light microscopy , 1994 .

[20]  L. Stookey.  Ferrozine---a new spectrophotometric reagent for iron , 1970 .

[21]  D. Stahl,et al.  Natural relationships among sulfate-reducing eubacteria , 1989, Journal of bacteriology.

[22]  B. B. J�rgensen,et al.  Volatile Fatty Acids and Hydrogen as Substrates for Sulfate-Reducing Bacteria in Anaerobic Marine Sediment , 1981, Applied and environmental microbiology.

[23]  F. Widdel,et al.  Phospholipid Ester-linked Fatty Acid Biomarkers of Acetate-oxidizing Sulphate-reducers and Other Sulphide-forming Bacteria , 1986 .

[24]  B. Jørgensen,et al.  Temperature dependence and rates of sulfate reduction in cold sediments of svalbard, arctic ocean , 1998 .

[25]  B. Jørgensen.  Mineralization of organic matter in the sea bed—the role of sulphate reduction , 1982, Nature.

[26]  M. Collins,et al.  Respiratory Quinones of Sulphate-Reducing and Sulphur-Reducing Bacteria: A Systematic Investigation , 1986 .