Biochemical characterization and enhanced production of endoxylanase from thermophilic mould Myceliophthora thermophila.

Abstract

Endoxylanase production from M. thermophila BJTLRMDU3 using rice straw was enhanced to 2.53-fold after optimization in solid state fermentation (SSF). Endoxylanase was purified to homogeneity employing ammonium sulfate precipitation followed by gel filtration chromatography and had a molecular mass of ~ 25kDa estimated by SDS-PAGE. Optimal endoxylanase activity was recorded at pH 5.0 and 60°C. Purified enzyme showed complete tolerance to n-hexane, but activity was slightly inhibited by other organic solvents. Among surfactants, Tweens (20, 60, and 80) and Triton X 100 slightly enhanced the enzyme activity. The Vmax and Km values for purified endoxylanase were 6.29µmol/min/mg protein and 5.4mg/ml, respectively. Endoxylanase released 79.08 and 42.95% higher reducing sugars and soluble proteins, respectively, which control after 48h at 60°C from poultry feed. Synergistic effect of endoxylanase (100U/g) and phytase (15U/g) on poultry feed released higher amount of reducing sugars (58.58mg/feed), soluble proteins (42.48mg/g feed), and inorganic phosphate (28.34mg/feed) in contrast to control having 23.55, 16.98, and 10.46mg/feed of reducing sugars, soluble proteins, and inorganic phosphate, respectively, at 60°C supplemented with endoxylanase only.