Culture conditions for the production of amylolytic enzymes by a thermophilic Clostridium sp.

The growth of a thermophilic Clostridium sp. and the production of α-glucosidase, α-amylase and pullulanase were studied under anaerobic conditions using different carbon and nitrogen sources and varying pH values and temperatures. Growth and enzyme activities were highest with soybean meal as the nitrogen source. The optimum concentration was 2.5% [w/v] for the production of α-amylase as well as pullulanase and 2% [w/v] for α-glucosidase. The best carbon source proved to be soluble starch for α-amylase, and pullulanase and maltose for α-glucosidase. Growth and enzyme production reached their optimum at pH 6.5 to 7.0 and 70°C. Under these conditions, the enzyme activities followed exponential growth with maximum yields of α-glucosidase, α-amylase and pullulanase at 28, 36, and 44 h.