Studies on the factors influencing the digestion of rice straw by Cellulomonas
A cellulose-decomposing bacterium has been isolated from soil and identified as a member of the genus Cellulomonas. Rice straw which was delignified with 1% (w/w) sodium hydroxide, then treated with 60% (v/v) phosphoric acid to increase the swelling capacity, could be used effectively by cellulase of Cellulomonas. The effects of other conditions such as pH, nitrogen source, substrate concentration and incubation time on the production of filter paper and endoglucanase activity were studied. Maximum production of endoglucanase and filter paper activity occurred at 28 degrees C in 7 days, in the presence of 1% treated rice straw as substrate at an initial pH of 3.0 when NaNO3 was used as source of nitrogen. Under these conditions, cellulolytic activity of culture filtrates appears to be very close to that for Trichoderma reesei grown in the same substrate.