A thermophilic, anaerobic, spore-forming bacterium (strain JW/AS-Y6) was isolated from a mixed sediment-water sample from a hot spring (Calcite Spring area) at Yellowstone National Park. The vegetative cells of this organism were straight rods, 0.4 to 0.6 by 3.0 to 6.5 μ.m. Cells occurred singly and exhibited a slight tumbling motility. They formed round refractile endospores in terminal swollen sporangia. Cells stained gram positive. The temperature range for growth at pH 6.8 was 43 to 65°C, with optimum growth at 58°C. The range for growth at 60°C (pH; with the pH meter calibrated at 60°C) was 5.9 to 7.8, with an optimum pH600 of 6.3 to 6.5. The substrates utilized included glycerol, glucose, fructose, mannose, galactose, xylose, lactate, glycerate, pyruvate, and yeast extract. In the presence of CO, acetate was the only organic product from glycerol and carbohydrate fermentation. No H was produced during growth. The strain was not able to grow chemolitho-trophically at the expense of H-CO; however, suspensions of cells in the exponential growth phase consumed H. The bacterium reduced fumarate to succinate and thiosulfate to elemental sulfur. Growth was inhibited by ampicillin, chloramphenicol, erythromycin, rifampin, and tetracycline, but not by streptomycin. The G+C content of the DNA was 54.5 mol% (as determined by high-performance liquid chromatography). The 16S ribosomal DNA sequence analysis placed the isolate in the Gram type-positive subphylum. On the basis of physiological properties and phylogenetic analysis we propose that the isolated strain constitutes a new species, ; the type strain is JW/AS-Y6 (= DSM 11254 = ATCC 700316).


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error