Isolation, Screening, Characterization and Optimization of Xylanase Production from Thermostable Alkalophillic Fusarium sp. XPF5

Xylanases are the enzymes that hydrolyse xylans, a major constituent of hemicelluloses and have various biotechnological applications. It is produced by various microbial sources including fungi being most promising. In the present study, soil samples rich in plant dead material obtained from various locations Himalayan region around Solan, Himachal Pradesh, India, and screened for xylanase producing fungal isolates. Seven fungal isolates were selected on the basis of clear zone formation around the fungal growth for quantification of xylanase production. Among the seven fungal strains isolated, isolate XPF-5 was selected as hyper producing fungal strains showing highest enzyme activity (0.398 U/ml). The strain was identified microscopically as Fusarium sp. XPF-5 on the basis of morphological characteristics. Optimum temperature and pH for XPF-5 xylanase were found as 57⁰C and 9.0, respectively. The production of xylanase was optimized using different factors such as temperature, pH and time of incubation by ‘one variable at a time’ approach. The optimum temperature, pH and time of incubation for maximum xylanase production were obtained as 47⁰C, 8.0 and 96 h, respectively. Based on the results of culture conditions and xylanase activity, the fungal isolate XPF-5 was considered as thermo-alkalophile, and make it a potential candidate for large scale xylanase production and its use in biotechnological processes.