Production and characterization of a novel cold-activeß-glucosidase and its influence on aromatic precursors of Muscat wine  

作　　者：Brenda Bezus Stefani de Ovalle Paula González-Pombo Sebastián Cavalitto Ivana Cavello 

机构地区：[1]Centro de Investigación y Desarrollo en Fermentaciones Industriales(CINDEFI),UNLP,CCT La Plata-CONICET,Calle 47 y 115,La Plata,B1900ASH,Provincia de Buenos Aires,Argentina [2]Área Bioquímica,Departamento de Biociencias,Facultad de Química-UdelaR,General Flores 2124,CC1157,Montevideo,Uruguay

出　　处：《Food Bioscience》2023年第3期876-886,共11页食品生物科学（英文）

基　　金：supported by grants from the National Scientific and Technological Research Council and the National Agency for the Promotion of Science and Technology under Grants number PICT 2018-3194 and PICT 2019-3123.

摘　　要：ß-Glucosidases(ßGL)-widely used in the enological field-are enzymes that catalyze the liberation of aromatic volatiles from their glycosidic precursors during winemaking.In the present study,aßGL obtained from the Antarctic yeast Mrakia sp.LP 7.1.2016 was produced on a bioreactor scale,purified,characterized,and the enzyme’s properties studied for a potential enological application.Sodium-dodecylsulfate-polyacrylamide-gel electrophoresis indicated a high molecular weight for this enzyme,it having at least two subunits of 134 and 14 kDa.ßGL exhibited a pH optimum of 5.0 and retained substantial activity and stability at pH 4.0.The temperature range for optimal activity was 50-55℃,with the enzyme demonstrating thermostability up to 50℃ and retaining 87%of residual activity at that temperature after 3 h.The respective kinetic constants determined with p-nitrophenyl-ß-D-glucopyranoside and cellobiose were 0.38 and 1.79 mM for Km and 20.1 and 5.65μmol^(-1)mg^(-1)min^(.1) for Vmax,ß-Glucosidase manifested high activity in 10-25%(v/v)ethanol,30.0 mg L^(-1)sulfur dioxide,and 10-200 g L^(-1)fructose;but it was strongly inhibited by glucose,retaining only 6%of residual activity in the presence of 20 g L^(-1).Upon investigating the influence of the enzyme on Muscat-wine glycosidic precursors,we found significant differences in terpene content after 14 days ofßGL treatment at an eightfold increase over control-wine levels.The enzyme was more active toward the precursors of the monoterpenes nerol and geraniol and oxides of trans-and cis-linalool.These findings contribute to our understanding of the potential of cold-active enzymes in advantageous biotechnological applications to enology.

关 键 词：Antarctic yeasts Wine-aroma enhancement Cold-activeß-glucosidase Mrakia sp. MONOTERPENES Muscat wine 

分 类 号：TS201[轻工技术与工程—食品科学]