Changes

Exogenous beta-glycosidase activity has been shown to be much more effective at releasing aglycones from glycosides. 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 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. YeastSome 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 both varying degrees of beta-glucosidase activity, however the presence of glucose is often an inhibitor of this activity for various microbe species <ref name="Maicas"></ref>. ====Activity of Brettanomyces and Saccharomyces==== One study screened the beta-glucosidase activity of several strains of ''Saccharomyces cerevisiae'', ''Saccharomyces pastorianus'', and ''Brettanomyces'' spp <ref name="Daenen1">[http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2672.2007.03566.x/full Screening and other enzymes needed for evaluation of the glucoside hydrolase activity in Saccharomyces and Brettanomyces brewing yeasts. L. Daenen, D. Saison, F. Sterckx, F.R. Delvaux, H. Verachtert, G. Derdelinckx. 2007.]</ref>. None of the lager brewing strains showed beta-glucosidase activity. Out of 32 strains of ''S. cerevisiae'', only one strain (a wine strain called "U228") showed beta-glucosidase activity, however its activity was repressed in the presence of glucose. This indicates that most ''S. cerevisiae'' strains do not have the capability of producing beta-glucosidase, but it is possible that some very few strains can. Most of the strains of ''S. cerevisiae'', however, did release another enzyme called beta-glucanase, which led to varying degrees of breaking down a wide range some smaller glycosides found in hops containing the aglycones methyl salicylate, 1-octen-3-ol, and cis-3-hexen-1-ol, but not linalool. None of the ''B. bruxellensis'' strains showed this activity, but the only tested strain of ''B. custersianus'' and both of the ''B. anomala'' strains tested did show beta-glucosidase activity. In particular, the ''B. custersianus'' strain was tested against glycosides from hops, in which case high amounts of the algycones linalool (citrus, orange, lemon, floral <ref>[http://www.thegoodscentscompany.com/data/rw1007872.html "Linalool." The Good Scents Company. Retrieved 05/12/2016.]</ref>), methyl salicylate (minty, wintergreen <ref>[http://www.rsc.org/chemistryworld/2015/09/methyl-salicylate-oil-wintergreen-podcast "Methyl salicylate." Chemistry World. Retrieved 05/12/2016.]</ref>), 1-octen-3-ol (mushroom, earthy <ref>[http://www.thegoodscentscompany.com/data/rw1024051.html "1-octen-3-ol." The Good Scents Company. Retrieved 05/12/2016.]</ref>) and cis-3-hexen-1-ol (grassy, melon rind <ref>[http://www.thegoodscentscompany.com/data/rw1005932.html "(Z)-3-hexen-1-ol." The Good Scents Company. Retrieved 05/12/2016.]</ref>) were released. The beta-glucosidase activity remained the same when fermented alone, or when fermented with ''S. cerevisiae''. ''B. custersianus'' has been isolated from the later stages of lambic fermentation, and it is thought that its ability to varying degrees produce beta-glucosidase, which gives it the ability to ferment cellobiose and cellotriose, is a possible adaptation from living in oak barrels <ref name="MaicasDaenen1"></ref>.