Production and Characterization of Partially Purified Thermostable Endoxylanase and Endoglucanase from Novel Actinomadura geliboluensis and the Biotechnological Applications in the Saccharification of Lignocellulosic Biomass

Abstract

Extracellular endoxylanase and endoglucanase from halo- and thermo-tolerant Actinomadura geliboluensis were produced, purified, characterized, and used in the saccharification of native and pretreated lignocellulosic biomasses. The molecular mass of endoxylanase and endoglucanase were 30 and 38 kDa, respectively. The optimum pH and temperature values for both endoxylanase and endoglucanase activities were pH 6.0 and 60 °C, respectively. They were both stable within a pH range of 4.0 to 8.0 and up to 70 °C. The half-lives of endoxylanase and endoglucanase at 70 °C were calculated as 180 min and 60 min, while their half-lives at 80 °C were detected as 60 min and 50 min, respectively. Both the endoxylanase and endoglucanase obeyed Michaelis-Menten kinetics. The endoxylanase and endoglucanase from A. geliboluensis were strongly inhibited by Hg2+. Endoxylanase was activated by Mg2+ and Ca2+ and endoglucanase was activated by Fe2+ and Ca2+. The potential application of endoxylanase and endoglucanase in saccharification of lignocellulosic biomass was further evaluated. The reduced sugar was 265.12 mg/g biomass after both endoxylanase and endoglucanase were incubated with wheat straw, which was pretreated by 1 % NaOH at 121 °C for 15 min. Endoxylanase and endoglucanase were produced from novel A. geliboluensis, which could potentially be used in biotechnological applications.