Effect of Salt on the Production of Xylanase in some Thermophilic Fungi

Abstract

The fungal isolates was studied for the production of xylanase at different salt level i.e., 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0%. Xylanase was produced by growing the test fungus in Bhat and Maheshwari medium supplemented with 1% xylan as carbon source at pH 6.0. All the fungal isolates showed an increase in their xylanase activity with the increase in salt concentration upto a limit, thereafter it decreased. Chaetomium thermophile (1.21 U/mg protein), Humicola insolens (2.69 U/mg protein), Rhizopus stolonifer (1.25 U/mg protein) showed their highest activity at 1.5% salt level, while Humicola fuscoatra (1.25 U/mg protein), Humicola grisea (1.29 U/mg protein), Sporotrichum thermophile (1.19 U/mg protein) showed the highest activity at 2% salt level. Mucor sp (2.79 U/mg Protein) exhibited the highest activity at lower salt level (1%). Thermoascus aurantiacus (1.26 U/mg Protein) showed the double salt optima for xylanase activity, one at 1.5% and the other at 2.5% salt level.