Nutrient Requirements of Butyric Acid-Butyl Alcohol Bacteria.

Preliminary investigations have shown that Clostridium acetobutylicum and related butyric-acid butyl-alcohol bacteria, fail to develop in a synthetic medium containing only ammonium sulphate, inorganic salts and glucose. These results suggest that perhaps the organisms require complex nitrogen compounds or some specific growth factor. Wood, Tatum and Peterson (1937), Wood, Andersen and Werkman (1938) and Tatum, Wood and Peterson (1936) reported that an acidic ether-soluble factor extracted from Difco yeast extract and thiamin stimulate growth of propionic acid bacteria in an ammonium sulphate medium. Wood, Andersen and Werkman (1937a) (1937b) and Andersen, Wood and Werkman (1938) found that these stimulants were essential for growth of certain heterofermentative lactic acid bacteria in media containing hydrolyzed casein or purified amino acids. Andersen, Wood and Werkman (1937) described a homofermentative lacticacid organism utilizing ammonium sulphate in the presence of lactoflavin, thiamin and the ether-soluble extract of yeast extract. The present investigation is a continuation of these studies using butyric-acid butyl-alcohol bacteria. Preliminary results (Brown, Wood and Werkman (1938a, 1938b) have shown, in media containing ammonium sulfate, glucose and Speakman's salt, that an ether extract of yeast extract is essential for growth of the butyl-alcohol bacteria. The yeast factor is not essential