Isolation and lignocellulolytic activities of fiber-digesting bacteria from digestive tract of termite (Cryptothermes sp.)

Abstract

The objectives of this study were to obtain the fiber-digesting bacteria isolates from termite digestive tract and to determine the optimum conditions of growth and production of cellulase, xylanase and ligninase enzyme of isolate. The first study was conducted to isolate and select the fiber-digesting bacteria from the digestive tract of termites based on the highest activity of cellulolytic (S), xylanolytic (X) and lignolytic (L). The second study was optimation of the growth conditions of bacteria and the enzyme production due to effect of rice straw substrate and nitrogen. The material used were dry wood termites, rice straw, and culture medium. The design used was a completely randomized factorial design, in which the first factor was rice straw substrate (1, 2, and 3% W/V), while the second factor was nitrogen (0.1, 0.2 and 0.3% W/V). Variables measured were cellulase, xylanase and ligninase activities. Results of the first sudy showed that the isolates obtained consisted of 3 types, those were cellulolytic bacteria (S1, S2, and S3), 3 types of bacteria xylanolytic (X1, X2, and X3) and 3 types of bacteria lignolytic (L1, L2, and L3). Meanwhile, results of the second study showed that isolates of S2, X3, and L1 had the highest activity, those were 1.894 U/mL, 1.722 U/mL and 0.314 U/mL, respectively. In conclusion, the addition of 1% level of rice straw substrate and 0.3% of nitrogen showed the highest enzyme activity on cellulase, xylanase and ligninase.