University of Nottingham, School of Chemistry, Department of Chemical Biology, University Park, Nottingham, NG7 2RD, UK.
Dipartimento di Bioscienze, Università di Milano, Via Celoria 26, 20133, Milan, Italy.
Chembiochem. 2021 Apr 6;22(7):1223-1231. doi: 10.1002/cbic.202000688. Epub 2020 Dec 30.
β-Glucosidases are used in the food industry to hydrolyse glycosidic bonds in complex sugars, with enzymes sourced from extremophiles better able to tolerate the process conditions. In this work, a novel β-glycosidase from the acidophilic organism Alicyclobacillus herbarius was cloned and heterologously expressed in Escherichia coli BL21(DE3). AheGH1 was stable over a broad range of pH values (5-11) and temperatures (4-55 °C). The enzyme exhibited excellent tolerance to fructose and good tolerance to glucose, retaining 65 % activity in the presence of 10 % (w/v) glucose. It also tolerated organic solvents, some of which appeared to have a stimulating effect, in particular ethanol with a 1.7-fold increase in activity at 10 % (v/v). The enzyme was then applied for the cleavage of isoflavone from isoflavone glucosides in an ethanolic extract of soy flour, to produce soy isoflavones, which constitute a valuable food supplement, full conversion was achieved within 15 min at 30 °C.
β-葡萄糖苷酶在食品工业中用于水解复合糖中的糖苷键，而源自极端微生物的酶更能耐受该过程条件。在这项工作中，从嗜酸菌 Alicyclobacillus herbarius 中克隆并异源表达了一种新型的β-糖苷酶。AheGH1 在很宽的 pH 值（5-11）和温度（4-55°C）范围内稳定。该酶对果糖表现出极好的耐受性，对葡萄糖也有良好的耐受性，在 10%（w/v）葡萄糖存在下保留 65%的活性。它还能耐受有机溶剂，其中一些似乎具有刺激作用，特别是乙醇，在 10%（v/v）时活性增加了 1.7 倍。然后，该酶被用于从大豆粉的乙醇提取物中的大豆异黄酮苷中切割异黄酮，以生产大豆异黄酮，大豆异黄酮构成有价值的食品补充剂，在 30°C 下 15 分钟内即可完全转化。
