Physioiogical Properties of Clostridia Isolated from the Sediment in the Edo River Mouth

Abstract

One hundred and thirty eight strains of obligately anaerobic heterotrophs, genus Clostridium, were isolated from the sediment in the Edo River mouth using 5 different agar media, and examined for 19 physiological characteristics. Almost all strains produced proteolytic and saccharolytic enzymes and lecithinase. Few or none of the isolates produced cellulase, chitinase and lipase. Many organisms could grow in 0 to 2% NaCl and at 20°C to 37°C. Obligate halophiles were not isolated from the estuarine sediment. It is shown from the characteristics of casein hydrolysis, fermentation of lactose and sucrose and growth at 10°C that the clostridial composition varied with the temperature and/or with the medium to be isolated.
The isolates were classified into 13 groups based on 7 characteristics which are important in the taxonomy of genus Clostridium. Groups 3, 5 and 7 showed relatively high proportions of the isolates. Especially group 5 which seems to be C. perfringens, distributed widely in the sediment of the inner part of Tokyo Bay.