KINETICS OF β-GLUCAN DEGRADATION IN WORT BY EXOGENOUS β-GLUCANASES TREATMENT

Abstract
Three commercial β-glucanases, one bacterial (Cereflo 200L from Novo) and two fungal (Biobeta from Gist-Brocades and Filtrase from Biocon) have been studied with regard to the hydrolysis of β-glucan in sweet and hopped wort. At temperatures below 70°C these processes follow first order kinetics with rate constants being directly proportional to the enzyme concentrations. The rate constant for bacterial β-glucanase Cereflo 200L shows a negative dependence on temperature but positive with wort pH, whereas the reverse is the case for the two fungal β-glucanases. Within the ranges of pH and temperature tested the bacterial β-glucanase has 2–5 times the activity of the fungal ones. No evidence for synergic or competitive effects between bacterial and fungal β-glucanases have been found.