Clostridium lortetii sp. nov., a halophilic obligatory anaerobic bacterium producing endospores with attached gas vacuoles

A strain of Clostridium was isolated from Dead Sea sediment, differing from the previously described Clostridium types in its halophilic character. It required NaCl concentrations between 1 and 2 M, and optimal growth was found in 1.4-1.5 M NaCl at 30° C and in 1.7 M NaCl at 45° C. In sporulating cells gas vacuoles developed, generally near the developing terminal endospore only, and these vacuoles remained attached to the mature endospore after degeneration of the vegetative cell. Fermentation products included acetate, butyrate and hydrogen. Glucose and a few other carbohydrates stimulated growth, though they were poorly utilized. A new species name has been proposed for the organism: Clostridium lortetii.