SUBSTRATE SPECIFICITY AND NATURE OF ACTION OF BARLEY β‐GLUCAN SOLUBILASE

Abstract

Barley β/glucan solubilase was shown to be active, to differing extends, towards hot water (65°C) soluble β‐glucan, CM‐cellulose and cellodextrins (DP 2–8). However, the enzyme did not affect the viscosity of CM‐pachyman or appear to solubilise cotton cellulose. When β/glucan was treated with lichenase a mixture of small molecular weight products was obtained including a DP 9 dextrin. This dextrin was not obtained when the β‐glucan was treated with β‐glucan solubilase prior to hydrolysis by lichenase. It has been concluded, therefore, that this β‐glucan solubilase is an endo‐type glucanase, which appears to attack the small proportion of long blocks of (1→4)‐β‐linked glucosyl residues reputed to be present in barley β‐glucan. 1989 The Institute of Brewing & Distilling