| 论文题目: | Integrated expression of the alpha-amylase, dextranase and glutathione gene in an industrial brewer's yeast strain |
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| 作者: | Wang, JJ; Wang, ZY; He, XP; Zhang, BR |
| 联系作者: | Wang, ZY |
| 刊物名称: | WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY |
| 期: | 1 |
| 卷: | 28 |
| 页: | 223-231 |
| 年份: | 2012 |
| 影响因子: | 1.532 |
| 论文下载: | |
| 摘要: | 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 alpha-amylase to make up alpha-amylase's shortcoming which can only hydrolyze alpha-1,4-glycosidic bond. Meanwhile, 18s rDNA repeated sequence was used as the homologous sequence for an effective and stable expression of LSD1 gene. 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. |
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