Changes

Exogenous beta-glycosidase activity has been shown to be much more effective at releasing aglycones from glycosides in bacteria and fungi. For glycosides which contain a glucose, which is the majority, beta-glucosidase cleaves the sugar, thus releasing the aglycone. For glycosides that contain disaccharides, usually another enzyme must be present to first break down the disaccharide before the beta-glucosidase can release the aglycone (beta-xylosidase, alpha-arabinosidase, alpha-rhamnosidase, or beta-apiosidase) <ref name="Winterhalter"></ref>. However, glycosides in tea leaves that contain disaccharide sugars (cellulose/cellobiose <ref name="ucdavis_chemwiki">[http://chemwiki.ucdavis.edu/Core/Organic_Chemistry/Carbohydrates/Disaccharides "Disaccharides." UC Davis Chemwiki. Retrieved 05/15/2016.]</ref>) have been observed to be broken down without the use of these other enzymes; the beta-glucosidase cleaves the aglycone from the disaccharide on its own. Some species of yeast (''Debaryomyces castelli'', ''D. hansenii'', ''D. polymorphus'', ''Kloeckera apiculata'', ''Hansenula anomala'', and ''Brettanomyces'' spp), bacteria (''Oenococcus oeni''), and fungi (''Aspergillus niger'') have been found to have strain dependent beta-glucosidase activity, however several inhibitors for glucosidase activity vary for different strains of microbes. These inhibitors include the presence of glucose, pH, temperature, ethanol, and phenols <ref name="Maicas"></ref><ref name="Mansfield">[https://theses.lib.vt.edu/theses/available/etd-07262001-172630/unrestricted/Mansfieldthesis.pdf Quantification of Glycosidase Activities in Selected Strains of Brettanomyces bruxellensis and Oenococcus oeni. A. K. Mansfield, B. W. Zoecklein and R. S. Whiton. 2001.]</ref>. For example, for some strains of ''O. oeni'', as little as 10mg/L of glucose is enough to inhibit beta-glucosidase activity, or the presence of alcohol or typical wine pH (3.0 - 4.0) was enough to inhibit. Other strains of ''O. oeni'' are not inhibited by some or all of these inhibitors <ref>[http://www.sciencedirect.com/science/article/pii/S0168160505003296 A survey of glycosidase activities of commercial wine strains of Oenococcus oeni. Antonio Grimaldi, Eveline Bartowsky, Vladimir Jiranek. 2005.]</ref>.

===Activity of Brettanomyces and Saccharomyces===

Many strains of ''B. bruxellensis'' have also been found to have varying degrees of intracellular or parietal (attached to the cell wall) beta-glucosidase activity. ''Brettanomyces'' has more strains that can produce beta-glucosidase than other genera of yeast, and the strains generally also have a higher rate of beta-glucosidase activity than other genera of yeast <ref>[http://link.springer.com/article/10.1038/sj.jim.2900720 Quantification of glycosidase activities in selected yeasts and lactic acid bacteria. H McMahon, B W Zoecklein, K Fugelsang, Y Jasinski. 1999.]</ref><ref name="Mansfield"></ref>. Strains with higher beta-glucosidase activity have been isolated from lambic, suggesting that these strains may have an adapted ability to utilize sugar from glycosides <ref name="Vervoort">[http://onlinelibrary.wiley.com/wol1/doi/10.1111/jam.13200/abstract Characterization of the recombinant Brettanomyces anomalus β-glucosidase and its potential for bioflavoring. Yannick Vervoort, Beatriz Herrera-Malaver, Stijn Mertens, Victor Guadalupe Medina, Jorge Duitama, Lotte Michiels, Guy Derdelinckx, Karin Voordeckers, and Kevin J. Verstrepen. 2016.]</ref>. Some ''Brettanomyces'' strains may only be capable of beta-glucosidase activity, and not the other enzymes which are needed to break down disaccharide type glycosides. Additionally, cell death and autolysis can result in an increase in beta-glucosidase activity in solution due to the cell contents being released into solution <ref name="Mansfield"></ref>. Strains that can metabolize cellobiose tend to also have higher beta-glucosidase activity because the possess an extra gene for beta-glucosidase enzyme production <ref name="Crauwels1">[http://link.springer.com/article/10.1007/s00253-015-6769-9 Comparative phenomics and targeted use of genomics reveals variation in carbon and nitrogen assimilation among different Brettanomyces bruxellensis strains. S. Crauwels, A. Van Assche, R. de Jonge, A. R. Borneman, C. Verreth, P. Troels, G. De Samblanx, K. Marchal, Y. Van de Peer, K. A. Willems, K. J. Verstrepen, C. D. Curtin, B. Lievens. 2015]</ref>.

==See Also==