Integrated expression of the α-amylase, dextranase and glutathione gene in an industrial brewer’s yeast strain
Integrated expression of the α-amylase, dextranase and glutathione gene in an industrial brewer’s yeast strain
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DOI：
10.1007/s11274-011-0811-6
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发表时间：
2011-06
影响因子：
4.1
通讯作者：
Jinjing Wang;Zhaoyue Wang;Xiuping He;Bo-run Zhang
中科院分区：
文献类型：
--
作者：
Jinjing Wang;Zhaoyue Wang;Xiuping He;Bo-run Zhang
Genetic engineering is widely used to meliorate biological characteristics of industrial brewing yeast. But how to solve multiple problems at one time has become the bottle neck in the genetic modifications of industrial yeast strains. In a newly constructed strain TYRL21, dextranase gene was expressed in addition of α-amylase to make up α-amylase’s shortcoming which can only hydrolyze α-1,4-glycosidic bond. Meanwhile, 18s rDNA repeated sequence was used as the homologous sequence for an effective and stable expression ofLSD1gene. As a result, TYRL21 consumed about twice much starch than the host strain. Moreover TYRL21 speeded up the fermentation which achieved the maximum cell number only within 3 days during EBC tube fermentation. Besides, flavor evaluation comparing TYRL21 and wild type brewing strain Y31 also confirmed TYRL21’s better performances regarding its better saccharides utilization (83% less in residual saccharides), less off-flavor compounds (57% less in diacetyl, 39% less in acetaldehyde, 67% less in pentanedione), and improved stability index (increased by 49%) which correlated with sensory evaluation of final beer product.
