DEVELOPMENT OF CELLULASE-FREE XYLANASE-PRODUCING ANAEROBIC CONSORTIA FOR THE USE OF LIGNOCELLULOSIC WASTES

Consortia of anaerobic bacteria were developed from different samples collected from various ecosystems for producing xylanases. We develope d a promising thermophilic (KK-10) consortium producing cellulase-free xylanase (410 nkat ml(-1)) at 65-85 degrees C, pH 7-9, and mesophilic consortia PC-4, CC-2, and BD-2 exhibiting (580, 275, and 300 nkat ml( -1), respectively), elaborating xylanase with cellulases in the cultur e medium. The temperature and pH influenced the yield and pattern of x ylanase and cellulase production markedly of the selected consortia, w ith the optimum at 72 h of growth growth and pH 6.7. The maximum xylan ase activity was recorded for all the consortia at 37 degrees C except PC-3 and KK-10 consortia, which showed their highest activity at 55 d egrees C and 65 degrees C, respectively. BD2 consortium when cultivate d at 55 degrees C exhibited a several-fold increase in beta-glucosidas e activity as compared with other consortia. It also had a broad pH ra nge of 5-9 for the growth and xylanase production. A pH range between 6 and 7 was found optimum for other consortia. The maximum xylanase ac tivity of 592 nkat ml(-1) was detected with PC-4 consortium. The xylan ase of KK-10 could find industrial applications at higher temperatures , whereas neutral xylanases may be used in the food-processing industr ies.