The substrate specificity of crude mannanase was determined by incubating the crude enzymes with 1% (w/v) of various substrates under our identified optimal conditions. The substrates include LBG (Sigma-Aldrich, St. Louis, MO, USA), guar gum, (Sigma-Aldrich, St. Louis, MO, USA), carboxymethyl cellulose (Sigma-Aldrich, St. Louis, MO, USA), xylan from larchwood (Sigma-Aldrich, St. Louis, MO, USA), xylan from oat spelts (Sigma-Aldrich, St. Louis, MO., USA), xylan from birchwood (Sigma-Aldrich, St. Louis, MO, USA), Avicel (Merck, Darmstadt, Germany), and potato starch (Sigma-Aldrich, St. Louis, MO, USA). Then, the reducing sugar was determined using DNS method as described above. The highest mannanase activity was used as a baseline for relative activity comparison.
The effect of different chemicals on enzyme activity was performed in the presence of the tested chemicals in the enzyme activity assays under optimal conditions for each crude extract. The enzyme activity without any additional chemical was used as a baseline for relative activity comparison.
The effect of different chemicals on enzyme activity was performed in the presence of the tested chemicals in the enzyme activity assays under optimal conditions for each crude extract. The enzyme activity without any additional chemical was used as a baseline for relative activity comparison.