Author(s): Lien T, Madsen M, Rainey FA, Birkeland NK
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Abstract Rod-shaped, thermophilic bacteria with a sheath-like outer structure (toga) were isolated from hot oilfield water of a North Sea oil reservoir. One of the isolates, designated SJ95(T), is an obligately anaerobic, sheathed, Gram-negative, fermentative bacterium capable of reducing elemental sulfur to hydrogen sulfide and tolerating high salt concentrations. The optimum growth conditions for this isolate are 58-60 degrees Celsius and pH 6.5-7.0 with 3-4\% NaCl and 0.7\% MgSO(4). 7H(2)O in the medium. Vitamins are required for growth. Growth is stimulated by yeast extract. Cells of strain SJ95(T) vary in size from 1-2 to 40-50 micron in length and are motile with a subpolar flagellation. Cels grown on xylan have xylanase activity, presumably associated with the toga, and glucose isomerase activity was detected in xylose-grown cells. The DNA G+C content is 31 and 34 mol\%, determined by the thermal denaturation and HPLC methods, respectively. Phylogenetically, strain SJ95(T) is most closely related to Petrotoga miotherma with a 97.7\% similarity level between their 165 rDNA sequences. The DNA-DNA reassociation value between the two DNAs was 35.6\%. On the basis of differences in genotypic, phenotypic and immunological characteristics, strain SJ95t (=DSM 10674t) is proposed as the type strain of a new species, Petrotoga mobilis. It can be readily distinguished from P. miotherma by its motility.
This article was published in Int J Syst Bacteriol
and referenced in Journal of Petroleum & Environmental Biotechnology