| Abstract: | Bacillus cereus RW1 and Serratia marcescens RW3, isolated from the hind-gut of the termite Reticulitermes hesperus, both grew well on mesquite wood and produced moderate amounts of carboxymethylcellulase. Carboxymethylcellulose (CMC) gels were depolymerized rapidly by B. cereus RW1 and slowly by S. marcescens RW3. The depolymerization of CMC was pH and temperature sensitive. Depolymerization of gels by growing cultures of B. cereus RW1 and the action of cell-free extracts of B. cereus RW1 on CMC sols were optimum at pH 6.0 and 5.5, respectively. Glucose and cellobiose increased the rate of CMC gel depolymerization. Enzyme synthesis rather than growth was stimulated by the addition of glucose to a culture of RW1 growing on a non-cellulosic substrate. Bacillus cereus RW1 produced both cell-free and cell-bound carboxymethylcellulase. |
