Crude Enzymes from a Hericium Edible Mushroom Isolated in Japan: Variability in Milk-clotting Activity and the Ability to Coagulate Ultra-high-temperature Pasteurized Milk

Abstract

Eleven mycelial strains of the genus Hericium were isolated to investigate the variability in milk-clotting activity and ability to coagulate ultra-high-temperature pasteurized milk (UHT-milk) of their crude enzymes. As well, the antifungal activity of cheese prepared using the crude enzymes was assessed. Based on sequence analysis of ITS-5.8S ribosomal DNA, 8 strains were identified as H. erinaceus, 2 as H. abietis, and 1 as Hericium sp. Notable differences were observed among the species and within strains in terms of milk-clotting activity of the crude enzyme preparation. The UHT-milk coagulation ability was detected in 5 strains of H. erinaceus and showed no correlation with the potency of milk-clotting activity. Furthermore, all cheese samples prepared from low-temperature pasteurized milk using the crude enzymes from the 8 strains of H. erinaceus and ripened for 30 days at 13°C showed growth inhibitory activity toward Aspergillus niger NBRC 105649. Thus, the crude enzyme preparation from H. erinaceus may be useful for cheese production.