Production and Characterization of Crystalline Cellulose-Degrading Cellulase Components from a Thermophilic and Moderately Alkalophilic Bacterium

  • Kim, Dong-Soo (Department of Food Science and Technology, College of Engineering, Kyungsung University) ;
  • Kim, Cheorl-Ho (Genetic Engineering Research Institute, Korea Institute of Science and Technology)
  • Published : 1992.03.01


A moderately thermophilic, alkalophlic and powerful crystalline cellulose-digesting bacterium, Bacillus K-12, was isolated from filter paper wastes and found to be similar to Bacillus circulans or Bacillus pumilis, except for its ability to grow at a moderately high pH and temperature. The isolate grew at a pH ranging from 6 to 10 and at a temperature ranging from 35 to $65^{\circ}C$ and produced a large amount of cellulase components containing avicelase, xylanase, CMCase, and FPase when grown in avicel medium for 5 to 7 days at $50^{\circ}C$. The crude enzyme preparation from the culture broth hydrolyzed xylan, raw starch, pullulan and ${\beta}-1,3$ glucan such as laminarin. Furthermore, the enzyme hydrolyzed crystalline cellulose to cellobiose and glucose and had a broad pH activity curve (pH 6~9). The enzyme was stable up to $70^{\circ}C$.