Kjeld Ingvorsen

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A Gram-positive, extremely halotolerant bacterium was isolated from the Great Salt Lake, Utah, USA. The strain, designated NNT (= DSM 11805T), was strictly aerobic, rod-shaped, motile by peritrichous flagella and spore-forming. Strain NNT grew at salinities of 0-20% (w/v) NaCl. A distinctive feature of strain NNT was its optimal growth in salt-free medium.(More)
Strain AX-2T (T = type strain) was isolated from sediment of Great Salt Lake, Utah, USA. Optimal salinity for growth was 27% (w/v) NaCl and only a few carbohydrates supported growth of the strain. Strain AX-2T did not grow on complex substrates such as yeast extract or peptone. 16S rRNA analysis revealed that strain AX-2T was a member of the phyletic group(More)
Sulfate-reducing prokaryotes (SRP) cause severe problems like microbial corrosion and reservoir souring in seawater-injected oil production systems. One strategy to control SRP activity is the addition of nitrate to the injection water. Production waters from two adjacent, hot (80 degrees C) oil reservoirs, one with and one without nitrate treatment, were(More)
Bacterial sulfate reduction in the surface sediment and the water column of Lake Mendota, Madison, Wis., was studied by using radioactive sulfate (SO(4)). High rates of sulfate reduction were observed at the sediment surface, where the sulfate pool (0.2 mM SO(4)) had a turnover time of 10 to 24 h. Daily sulfate reduction rates in Lake Mendota sediment(More)
A cyanide-metabolizing bacterium, strain DF3, isolated from soil was identified as Alcaligenes xylosoxidans subsp. denitrificans. Whole cells and cell extracts of strain DF3 catalyzed hydrolysis of cyanide to formate and ammonia (HCN + 2H2O----HCOOH + NH3) without forming formamide as a free intermediate. The cyanide-hydrolyzing activity was inducibly(More)
Bacterial sulfate reduction activity (SRA) was measured in surface sediments and slurries from three sites in the Great Salt Lake (Utah, USA) using radiolabeled 35S-sulfate. High rates of sulfate reduction (363 ± 103 and 6,131 ± 835 nmol cm-3 d-1) were measured at two sites in the moderately hypersaline southern arm of the lake, whereas significantly lower(More)
The diversity of sulfate-reducing bacteria (SRB) in brackish sediment was investigated using small-subunit rRNA and dissimilatory sulfite reductase (DSR) gene clone libraries and cultivation. The phylogenetic affiliation of the most commonly retrieved clones for both genes was strikingly similar and produced Desulfosarcina variabilis-like sequences from the(More)
Apparent half-saturation constants (K m) and maximum uptake rates (V max) for sulfate were determined in four species ofDesulfovibrio of freshwater and marine origin using a35S-sulfate tracer technique. The lowerstK m (5 μM) was found in the freshwater speciesDesulfovibrio vulgaris (Marburg) and the highestK m (77 μM) in the marine speciesDesulfovibrio(More)
The diversity of sulfate-reducing bacteria (SRB) inhabiting the extreme hypersaline sediment (270 g L(-1) NaCl) of the northern arm of Great Salt Lake was studied by integrating cultivation and genotypic identification approaches involving PCR-based retrieval of 16S rRNA and dsrAB genes, the latter encoding major subunits of dissimilatory (bi) sulfite(More)
The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed for beta-xylanase activity between 5% and 15% NaCl, while(More)