摘要
glucanase was purified from a solid\|state culture of \%Trichoderma reesei \%on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G\|100 chromatography, and DEAE\|Sephadex A\|50 chromatography. The molecular mass was determined to be 35.21 kilodaltons by sodium dodecyl sulfate\|12.5% polyacrylamide gel electrophoresis. The \%β\%\|glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum temperature was 60 ℃, and \%β\%\|glucanase was relatively stable at below 40 ℃ for 60 min. The \%K\%\-m of the enzyme on \%β\%\|glucan was 10.86 mg/ml, and the \%V\%\-\{max\} on \%β\%\|glucan was 14286 μmol of glucose equivalents per mg of the pure enzyme per min. The \%β\%\|glucanase activity was significantly inhibited by Fe\+\{3+\} ions, and was reduced in the presence of Cu\+\{2+\} ions, Mn\+\{2+\} ions and Mg\+\{2+\} ions at 5 mmol/L and 10 mmol/L, respectively. The \%β\%\|glucanase activity was stimulated by Co\+\{2+\} ions, Ca\+\{2+\} ions, Zn\+\{2+\} ions, and Fe\+\{2+\} ions at 1 mmol/L and 5 mmol/L, respectively.
β-glucanase was purified from a solid-state culture of Trichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sepha-dex A-50 chromatography, rIlae molecular mass was determined to be 35.21 kilodahons by sodium dodecyl sulfate-12.5% polyacrylamide gel electrophoresis. The β-glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum temperature was 60℃, and β-glueanase was relatively stable at below 40° for 60min. The Km of the enzyme on β-glucan was 10.86 mg/ml, and the Vmax on β-glucanwas 14286 pmol of glucose equivalents per nag of the pure enzyme per rain. The β-glucanase activity was significantly inhibited by Fe^3+ ions, and was reduced in the presence of Cu^2+ ions, Mn^2+ ions and Mg^2+ ions at 5mmol/L and 10mmol/L, respectively. The β-glucanase activity was stimulated by Co^2+ ions, Ca^2 + ions,Zn^2+ ions, and Fe^2+ ions at 1mmol/L and 5mmol/L, respectively.
