Abstract

SCREENING, CHARACTERIZATION & OPTIMIZATION OF XYLANASE PRODUCTION FROM PSEUDOMONAS SPP. XPB-16 IN SUBMERGED FERMENTATION

Sunny Dhiman* and Gunjan Mukherjee

Abstract

The present research investigation reports an attempt to screen, characterize a xylanase hyper producing bacterial strain & to optimize culture conditions for maximum xylanase production. Carbon source, nitrogen source, production medium, substrate concentration, incubation time, production temperature, pH, inoculum size were the main parameters that were optimized for maximum xylanase production from the hyper producing bacterial strain. Various soil, compost and degrading wood samples were collected from the different places of Punjab and were enriched with xylan containing enrichment media. Primary screening of xylanase producing microbes was done on xylan agar media containing congo red. Quantitative assay of xylanase producing microbes for xylanase production was done on xylan containing submerged fermentation media. The resultant supernatants upon centrifugation at 10,000 rpm were assayed for xylanase activity. Hyper-xylanase producing strain was identified by morphological and biochemical tests and designated as Pseudomonas spp. XPB-16. Fructose (0.75%-w/v) was reported to be the most competent carbon source for xylanase production. Ammonium sulphate proved to be the most proficient nitrogen source amongst various organic & inorganic nitrogen sources. The optimum pH, temperature, inoculum size & substrate concentration for maximum xylanase production were 7.5, 35°C, 10% (w/v), 0.4% (w/v) respectively. Maximum xylanase production was recorded at 5.0% (w/v) yeast extract, 0.15% (w/v) KH2PO4, 0.015% (w/v) MgSO4 concentrations respectively. An inducer assisted time period of 36 h was reported optimum for maximum growth as well as maximum enzyme production from the hyper producer strain. Upon cultivating Pseudomonas spp. XPB-16 in optimized culture conditions; a 5.586 fold increase in xylanase production was recorded in comparison to xylanase production under unoptimized conditions. The prospects of xylan hydrolysis by xylanase from Pseudomonas spp. XPB-16 look quite promising. Thus future studies to increase the xylan hydrolysis rate as well as to assure enhanced process control for increased yield of xylanase would be envisaged.

Keywords: Xylanase, Xylan, Hemicellulases, Saccharification Glycoproteins, Optimization.