Abstract

The objective of this study was to evaluate the enzyme extracts from Cellulomonas flavigena cultured at different temperatures using sugarcane bagasse as substrate to determine the xylanolytic activity and the degradation of the enzyme extracts protein underin vitro rumen conditions. Three enzyme extracts were obtained by liquid fermentation at 30, 37 and 40°C from C. flavigena CDBB-531 to determine the xylanolytic activity and thein vitro ruminal enzyme protein degradation by measuring changes in ammonia nitrogen concentration as a response to incubation temperature. The highest xylanase activity was obtained at 37°C (linear P < 0.04, quadratic P < 0.001) as well as the highest concentration of extracellular protein (linear P < 0.001, quadratic P < 0.001) both highly correlated (r² = 0.93, P < 0.0002). As temperature was raised, the ammonia nitrogen concentration was increased (linear P < 0.001, quadratic P < 0.01), and the half time of degradation was reduced (linear P < 0.001, quadratic P < 0.01). The mean degradation half time was 23.95 h, which showed that the xylanolytic enzymes from C. flavigenaCDBB-531 degraded slowly indicating that they have the potential to be evaluated as exogenous enzymes for ruminants.

Key words: Cellulomonas flavigena, xylanases, in vitro degradation.