Abstract β-Amylase is important to the malting and brewing industry because it is one of four main enzymes involved in fermentable sugar production during mashing. There are two functional barley β-amylases encoded by the Bmy1 and Bmy2 genes. Mashing is commonly performed at high temperatures and β-amylase1 (Bmy1) is vulnerable to thermal inactivation at these temperatures. Unlike Bmy1, Bmy2 is not stored at useful levels in the mature grain but Bmy2 encodes a more thermostable β-amylase. Expression of β-amylase is not thought to occur during malting but, interestingly, de novo expression of Bmy2 is seen in other Triticeae tribe members during germination. Therefore, this research was conducted to determine if barley Bmy2 is de novo expressed during micromalting. De novo expression of Bmy2 is observed in both a two- and six-row malting cultivar (Conrad and Legacy, respectively). Legacy Bmy2 transcript levels significantly increased (40-fold) between 0 and 4 Days of Germination (DoG) and Conrad Bmy2 transcript levels significantly increased (20-fold) between 0 and 3 DoG. Legacy had significantly (1.9-fold) more Bmy2 transcript levels than Conrad by the end of micromalting. The β-amylase activity and protein immunoblots corroborated the gene expression data thus reliably demonstrating the de novo expression of Bmy2 during micromalting.

中文翻译：

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β-淀粉酶2 (Bmy2)在微型麦芽化过程中在大麦中的从头表达

摘要 β-淀粉酶是麦芽和酿造工业的重要组成部分，因为它是糖化过程中参与可发酵糖生产的四种主要酶之一。Bmy1 和 Bmy2 基因编码两种功能性大麦 β-淀粉酶。糖化通常在高温下进行，而 β-淀粉酶 1 (Bmy1) 在这些温度下容易发生热失活。与 Bmy1 不同，Bmy2 在成熟谷物中并未以有用的水平储存，但 Bmy2 编码更耐热的 β-淀粉酶。β-淀粉酶的表达被认为不会在麦芽制造过程中发生，但有趣的是，在萌发期间在其他小麦科部落成员中发现了 Bmy2 的从头表达。因此，进行这项研究是为了确定大麦 Bmy2 在微型麦芽制造过程中是否从头表达。在两行和六行麦芽栽培品种（分别为 Conrad 和 Legacy）中都观察到 Bmy2 的从头表达。Legacy Bmy2 转录水平在 0 到 4 天的萌发 (DoG) 之间显着增加（40 倍），而 Conrad Bmy2 转录水平在 0 到 3 DoG 之间显着增加（20 倍）。在微型麦芽制造结束时，Legacy 的 Bmy2 转录水平明显高于 Conrad（1.9 倍）。β-淀粉酶活性和蛋白质免疫印迹证实了基因表达数据，从而可靠地证明了 Bmy2 在微型麦芽制造过程中的从头表达。9 倍）到微型麦芽制造结束时，Bmy2 转录水平比康拉德高。β-淀粉酶活性和蛋白质免疫印迹证实了基因表达数据，从而可靠地证明了 Bmy2 在微型麦芽制造过程中的从头表达。9 倍）到微型麦芽制造结束时，Bmy2 转录水平比康拉德高。β-淀粉酶活性和蛋白质免疫印迹证实了基因表达数据，从而可靠地证明了 Bmy2 在微型麦芽制造过程中的从头表达。