Clostridium vincentii sp. nov., a new obligately anaerobic, saccharolytic, psychrophilic bacterium isolated from low-salinity pond sediment of the McMurdo Ice Shelf, Antarctica.
A gram-positive, motile, rod-shaped, strictly anaerobic bacterium was isolated from an enrichment initiated with sediment taken from below the cyanobacterial mat of a low-salinity pond on the McMurdo Ice Shelf, Antarctica. The organism grew optimally at 12 degrees C, at pH 6.5, and at an NaCl concentration of< 0.5% (w/v). It survived freeze-thawing at low salt concentrations,but not exposure to temperatures over 25 degrees C for more than 20 h or short-term exposure to temperatures> 50 degrees C. Out of a variety of polysaccharides tested as growth substrates, only xylan supported growth. The organism also grew on a variety of mono- and disaccharides including the cyanobacterial cell wall constituent, N-acetyl glucosamine. Fermentation products on a mol product per 100 mol of hexose monomer fermented basis were: acetate, 72; formate, 72; butyrate, 55; hydrogen, 114; and CO2, 100. Not detectable in the culture medium(< 2 mol per 100 mol of monomer) were lactate, propionate, ethanol,n-propanol, n-butanol, and succinate. The G+C content of the DNA from the bacterium was 33 mol%, and a phylogenetic analysis indicated that it grouped closely with members of the RNA-DNA homology group 1 of the genus Clostridium. It differed from other species of this genus with regard to growth temperature optimum, substrate range, and fermentation pattern, and is therefore designated as a new species of Clostridium for which the name Clostridium vincentii is proposed. The type strain is lac-1 (DSM 10228).
Mountfort
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Cawthron Institute, Private Bag 2, Nelson, New Zealand.
Rainey
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Burghardt
J
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Kaspar
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Stackebrandt
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D003013:Clostridium / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D005285:Fermentation; D019015:Geologic Sediments; D005947:Glucose / Q000378:metabolism; D007785:Lactose / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013379:Substrate Specificity; D014871:Water Microbiology
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D005947:Glucose; D007785:Lactose