Main content area

Characterization of a Thermostable and Acidic-Tolerable β-Glucanase from Aerobic Fungi Trichoderma koningii ZJU-T

Wang, J.-L., Ruan, H., Zhang, H.-F., Zhang, Q., Zhang, H.-B., He, G.-Q., Shen, S.-R.
Journal of food science 2007 v.72 no.9 pp. C452
Hypocrea koningii, beta-glucanase, heat stability, acid tolerance, chemical structure, enzyme activity, temperature, pH, potassium, cations, denaturation, enzyme inhibitors, urea, food additives
An extreme thermostable and acidic tolerable β-glucanase was isolated and characterized from aerobic fungi Trichoderma koningii ZJU-T. The optimal reaction temperature and pH for the β-glucanase were 100 °C and pH 2.0, respectively. The β-glucanase showed increased stability at higher temperatures and lower pH values when compared to other β-glucanases. The optimum conditions for the β-glucanase stability were found to be pH 4.0 and 80 °C. Even subjected to 100 °C for 3 h, β-glucanase activity did not show significant reduction. Moreover, K⁺ significantly enhanced β-glucanase activity at the concentration of 1 mM, while EDTA and other metal ions such as Mg²⁺, Mn²⁺, Zn²⁺, Ca²⁺, Fe²⁺, Pb²⁺, and Fe³⁺ inhibited β-glucanase activity. Denaturants, including sodium dodecyl sulfate (SDS) and mercaptoethanol, also inhibited β-glucanase activity at a concentration of 5%. However, in the presence of 7 M urea, residual activity of the β-glucanase still remained 14.5%.