Growth requirements of Clostridium saccharolyticum, an ethanologenic anaerobe

Abstract

Clostridium saccharolyticum, an obligate anaerobe, which can convert cellulose hydrolysis products to ethanol, acetic acid, H2, and CO2, grew well in a synthetic salt–vitamin medium when supplemented with 1% yeast extract. It also required iron and a reduced form of sulfur, such as cysteine or Na2S (1–10 mM). Good growth occurred in cellobiose, glucose, and xylose syrups of 20, 15, and 10% (w/v), respectively. Clostridium saccharolyticum was not affected by the accumulation of high headspace pressures of H2 or CO2, and grew well in the presence of 0.1 M acetate and 0.5 M ethanol, while 0.24 M acetate and 1.0 M ethanol inhibited growth. The results indicated that C. saccharolyticum has biotechnological potential for the conversion of cellulose and hemicellulose hydrolysis products to ethanol.