CLOSTRIDIUM AUTOETHANOGENUM, SP-NOV, AN ANAEROBIC BACTERIUM THAT PRODUCES ETHANOL FROM CARBON-MONOXIDE

A strictly anaerobic, gram-positive, spore-forming, rod-like, motile b acterium was enriched from rabbit feces, and isolated using carbon mon oxide as sole source of energy and carbon. The isolate metabolizes CO with ethanol, acetate and CO2 as end-products. Other substrates used a s carbon and energy sources include CO2 plus H-2, pyruvate, xylose, ar abinose, fructose, rhamnose, and L-glutamate. The optimum temperature for growth is 37 degrees C. The optimum pH for chemolithotrophic growt h lies around 5.8 to 6.0. Sulfate is not reduced. Growth is inhibited either by penicillin, chloramphenicol, tetracyclin or ampicillin, each at 100 mu g per ml. The isolate has a DNA-base composition of 25.9 +/ - 0.6% guanine plus cytosine. The isolate represents a new species of Clostridium for which the name Clostridium autoethanogenum is proposed . The type strain is strain JA1-1