Identification of Beer Gushing Caused by Microbial Infection of Schooner Barley

Abstract

Fungal infection of barley and malt, particularly by strains of the genus Fusarium, is a direct cause of beer gushing. The aim of this investigation was to isolate and identify the fungi from infected barley that cause beer gushing. One fungal strain was isolated from Schooner barley and induced beer gushing of more than 63.1 g/610 mL of beer with 1 mg of protein extract. Through morphological observation and 26S ribosomal DNA sequence alignment, the strain was identified as F. poae. The remarkable protein that induced beer gushing was isolated by gel-exclusion chromatography and purified by ion-exchange chromatography. The purified beer gushing-inducing protein (BGIP) increased the gushing potential to 75.4 g/610 mL of beer with 1 mg of BGIP. The relative molecular mass of the purified protein was estimated at 16 kDa by SDS-PAGE analysis.