ORIGINAL RESEARCH Open Access Simultaneous production of animal feed enzymes (endoxylanase and endoglucanase) by Penicillium janthinellum from waste jute caddies

Background: In West Bengal, India, a huge amount of lignocellulosic jute waste products, in the form of unutilized cut pieces of jute caddies consisting 65% cellulose, 22.5% hemicellulose, and 11% lignin, is generated from jute industries. Naturally, the high percentage of lignocellulolytic material made it an attractive substrate for the hydrolytic cleavage of lignocellulolytic enzymes, namely xylanases and cellulases. The present study aims for the production of xylanolytic and cellulolytic enzymes by a fungal isolate Penicillium janthinellum MTCC10889 using a cheap medium containing residual jute caddies obtained from jute mill wastes and chemically defined basal medium under submerged fermentation. Results: The fungal isolate P. janthinellum MTCC10889 is an outstanding producer of endoxylanase and also cellulase. A central composite design was applied to optimize its lignocellulolytic as well as cellulolytic enzyme production in submerged-state fermentation. The impact of three quantitative variables, namely pH, temperature, and substrate concentrations, on enzyme production was investigated by using a chemically defined basal medium supplemented with jute caddy as substrate. Such optimum conditions were as follows: pH 7.47, temperature of 30.35°C, and substrate concentration of 1.70% for endoxylanase, and pH 7.51, temperature of 29.69°C, and substrate concentration of 2.11% for cellulase production. Conclusions: A combination of one-factor-at-a-time approach is replaced by response surface methodology using central composite design, which resulted in 3.08- and 3.84-fold increases in the yields of endoxylanase (1,750 IU/ml) and endoglucanase (192 IU/ml), respectively. The highest endoxylanase