Methanol utilization by a novel thermophilic homoacetogenic bacterium, Moorella mulderi sp. nov., isolated from a bioreactor.
A thermophilic, anaerobic, spore-forming bacterium (strain TMS) was isolated from a thermophilic bioreactor operated at 65 degrees C with methanol as the energy source. Cells were gram-positive straight rods, 0.4-0.6 microm x 2-8 microm, growing as single cells or in pairs. The temperature range for growth was 40-70 degrees C with an optimum at 65 degrees C. Growth was observed from pH 5.5 to 8.5, and the optimum pH was around 7. The salinity range for growth was 0-45 g NaCl l(-1 )with an optimum at 10 g l(-1). The isolate was able to grow on methanol, H(2)-CO(2 )(80/20%, v/v), formate, lactate, pyruvate, glucose, fructose, cellobiose and pectin. The bacterium reduced thiosulfate to sulfide. The G+C content of the DNA was 53 mol%. Comparison of 16S rRNA genes revealed that strain TMS is related to Moorella glycerini (96%, sequence similarity), Moorella thermoacetica (92%) and Moorella thermoautotrophica (92%). On the basis of physiological and phylogenetic differences, strain TMS is proposed as a new species within the genus Moorella, Moorella mulderi sp. nov. (=DSM 14980, =ATCC BAA-608).
Balk
Melike
M
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT, Wageningen, The Netherlands. Melike.Balk@wur.nl
Weijma
Jan
J
Friedrich
Michael W
MW
Stams
Alfons J M
AJ
D000085:Acetates / Q000378:metabolism; D001482:Base Composition / Q000235:genetics; D001483:Base Sequence; D019149:Bioreactors / Q000382:microbiology*; D016937:Gram-Positive Endospore-Forming Rods / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D006358:Hot Temperature; D000432:Methanol / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D013379:Substrate Specificity; D013885:Thiosulfates / Q000378:metabolism
D000085:Acetates; D012336:RNA, Ribosomal, 16S; D013885:Thiosulfates; D000432:Methanol