PHYSIOLOGICAL-STUDIES OF CELLULASE (AVICELASE) SYNTHESIS IN STREPTOMYCES-RETICULI

Cellulase (Avicelase, Cell) from Streptomyces reticuli efficiently hyd rolyzes crystalline cellulose (Avicel) to cellobiose. The synthesis of the enzyme was found to be dependent on the presence of insoluble Avi cel but not on either soluble hydroxyethylcellulose, cellooligomers, o r cellobiose. Glycerol and various metabolizable mono- and disaccharid es repress Avicelase synthesis, whereas yeast extract has no inducing or repressing effect. Glucose kinase is not required for the repressio n effect. In the course of cultivation, S. reticuli secretes significa nt quantities of acid, predominantly pyruvate and succinate,,which red uce the pH to 4 in commonly used media with low buffering capacity. Co mparative studies with media with low and high buffering capacities re vealed that Avicelase synthesis is strongly repressed at a low pH.