Enhanced leavening properties of baker's yeast overexpressing MAL62 with deletion of MIG1 in lean dough
Enhanced leavening properties of baker's yeast overexpressing MAL62 with deletion of MIG1 in lean dough
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DOI：
10.1007/s10295-012-1144-7
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发表时间：
2012-10-01
影响因子：
3.4
通讯作者：
Xiao, Dongguang
中科院分区：
文献类型：
--
作者：
Sun, Xi;Zhang, Cuiying;Xiao, Dongguang
本研究旨在提高工业面包酵母的麦芽糖发酵，以提高其发酵性能。为此，我们过表达MAL 62编码α-葡萄糖苷酶（麦芽糖酶）和删除MIG 1编码的转录抑制剂，调节MAL基因的表达。当在葡萄糖-麦芽糖低糖模型液体面团（LSMLD）中测试时，过表达MAL 62的菌株显示出比亲本菌株高46.3%的α-葡糖苷酶活性和增强的离开活性。删除MIG 1的效果要差得多，但它可以进一步加强过表达MAL 62的菌株的发酵特性。通过对麦芽糖通透酶和α-葡萄糖苷酶基因的转化，进一步剖析了二者之间的关系。结果表明，在不提高麦芽糖通透酶活性的情况下，α-葡萄糖苷酶活性的提高也能促进麦芽糖代谢。先前的菌株改良策略针对的是一致地增强α-葡糖苷酶和麦芽糖通透酶活性。我们的研究结果表明，增加α-葡萄糖苷酶的活性是足以提高麦芽糖发酵在瘦面团。
This study aimed to increase maltose fermentation in industrial baker's yeast to increase its leavening properties. To this end, we overexpressed MAL62 encoding alpha-glucosidase (maltase) and deleted MIG1 encoding a transcriptional repressor that regulates MAL gene expression. Strain overexpressing MAL62 showed 46.3 % higher alpha-glucosidase activity and enhanced leaving activity than the parental strain when tested in glucose-maltose low sugar model liquid dough (LSMLD). Deleting MIG1 was much less effective, but it could further strengthen leavening properties in a strain overexpressing MAL62. The relationship between maltose permease and alpha-glucosidase was further dissected by transforming the two genes. The results indicated that without increasing the maltose permease activity, maltose metabolism could also be enhanced by the increased alpha-glucosidase activity. Previous strategies for strain improvement have targeted the enhancement of alpha-glucosidase and maltose permease activities in concert. Our results suggest that increasing alpha-glucosidase activity is sufficient to improve maltose fermentation in lean dough.