[Isolation and identification of a thermophilic anaerobic bacterium].
OBJECTIVE
To find new microbial resources from a high-temperature oil reservoir.


METHODS
Strain HL-3 was isolated by Hungate Anaerobic Technique from oil reservoir water sampled from Dagang oilfield, China. Through physiological, biochemical and phylogenetic analysis, the strain HL-3 was classified.


RESULTS
Cells were Gram-positive. The temperature range for growth was 40 degrees C-75 degrees C (optimum at 60 degrees C) and the pH range was 5.0-8.0 (optimum at 6.5). The isolate could grow in the presence of 0%-3.2% NaCl (optimum at 0.25%). Glucose, ribose, mannose, xylose and cellobiose could be metabolized. Metabolites of glucose were ethanol, acetate, CO2 and trace amount of propionate and butanol. The G + C content of DNA was 33.9 mol%. Based on 16S rRNA studies,strain HL-3 was most close to T. uzonensis DSM 18761T (EF530067) with 98.8% similarity and to T. sulfurigignens DSM 17917T (AF234164) with the 98.1% similarity. Strain HL-3 tolerated to high sulfite (0. 1mol/L) ions and extremely high concentration of thiosulfate (0.8 mol/L). When the concentration of thiosulfate was higher than 0.075 mol/L, the cell would generate S element granular. The presence of H2S gas was detected inside of space at the top of serum bottle. Strain HL-3 together with T. uzonensis DSM 18761T differed greatly in toleration of thiosulfate and sulfite. The toleration of strain HL-3 to thiosulfate and sulfite was most close to T. sulfurigignens DSM 17917T (AF234164). In addition, strain HL-3 to metabolite thiosulfate and sulfite was also similar with T. sulfurigignens DSM 17917T (AF234164). However, it differs largely from both of them to metabolize glucose.


CONCLUSIONS
Therefore, strain HL-3 may be a new spieces of the Thermoanaerobacter, and the definitive classification positioning is still awaiting for further verified with the method of determination of whole-genome DNA-DNA similarity
Biogas Institute of Ministry of Agricultural, Chengdu 610041, China. haichangliu198510@163.com
Haichang
H
Liu
Guihong
G
Lan
Quanquan
Q
Liu
Yi
Y
Cao
Yu
Y
Deng
Hui
H
Zhang
D001421:Bacteria, Anaerobic / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005648:Fuel Oils / Q000382:microbiology*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013447:Sulfites / Q000378:metabolism; D046968:Thermoanaerobacter / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D013885:Thiosulfates / Q000378:metabolism
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005648:Fuel Oils; D012336:RNA, Ribosomal, 16S; D013447:Sulfites; D013885:Thiosulfates