OPTIMIZATION OF CELLULASE-FREE XYLANASE PRODUCED BY A POTENTIAL THERMOALKALOPHILIC PAENIBACILLUS SP.N1 ISOLATED FROM HOT SPRINGS OF NORTHERN HIMALAYAS IN INDIA

Abstract

Hot spring bacteria are found a novel source of highly active xylanase enzyme with significant activity at high temperature. Among bacteria, Paenibacillus sp.N1 isolated from hot water spring of Manikaran, H.P., India showed highest 24.60 IU.ml-1 of cellulase-free xylanase on Reese medium. Growth conditions including medium, incubation time, pH, temperature, inoculum size, aminoacids, carbon sources, nitrogen sources and additives that affect the xylanase production by Paenibacillus sp.N1 were studied sequentially using the classical “change-one factor at a time†method. The optimal cultivation conditions predicated from canonical analysis of this model were achieved by using basal salt medium on 3rd day, pH 9.0, temperature 50ºC with inoculum size of 12.5%, phenylalanine as aminoacid, xylose as carbon source, (NH4)2HPO4 as nitrogen source and Tween 20 as detergent added with an approximate yield of 52.30 IU.ml-1 escalating the over level of xylanase production by 113.38%. A rare combination of all characters i.e. thermoalkalophilic nature and high units of cellulase-free xylanase produced from a new Paenibacillus sp.N1 make it of special industrial interest.