Novel strategy for yeast construction using δ-integration and cell fusion to efficiently produce ethanol from raw starch
Novel strategy for yeast construction using δ-integration and cell fusion to efficiently produce ethanol from raw starch
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DOI：
10.1007/s00253-009-2198-y
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发表时间：
2010-02-01
影响因子：
5
通讯作者：
Kondo, Akihiko
中科院分区：
文献类型：
--
作者：
Yamada, Ryosuke;Tanaka, Tsutomu;Kondo, Akihiko
我们开发了一种新的策略来构建酵母，以提高淀粉酶基因的表达水平和酵母的实用潜力，通过细胞融合将δ整合和多倍化相结合。将牛链球菌α-淀粉酶和根霉葡糖淀粉酶/α-凝集素融合蛋白基因整合到单倍体酵母菌株中。通过交配将这些单倍体菌株构建成二倍体菌株，然后通过细胞融合构建成四倍体菌株。与亲本菌株相比，四倍体菌株的α-淀粉酶和葡糖淀粉酶活性分别增加了1.5倍和10倍。二倍体和四倍体菌株比单倍体菌株增殖更快，产生更多的细胞，并且更有效地发酵葡萄糖。从生淀粉乙醇生产率提高倍性增加;四倍体菌株消耗150克/升的生淀粉，并产生70克/升的乙醇发酵72小时后。我们构建酵母的策略导致整合到基因组中的基因的同时过表达和酵母的实用潜力的改善。
We developed a novel strategy for constructing yeast to improve levels of amylase gene expression and the practical potential of yeast by combining delta-integration and polyploidization through cell fusion. Streptococcus bovis alpha-amylase and Rhizopus oryzae glucoamylase/alpha-agglutinin fusion protein genes were integrated into haploid yeast strains. Diploid strains were constructed from these haploid strains by mating, and then a tetraploid strain was constructed by cell fusion. The alpha-amylase and glucoamylase activities of the tetraploid strain were increased up to 1.5- and tenfold, respectively, compared with the parental strain. The diploid and tetraploid strains proliferated faster, yielded more cells, and fermented glucose more effectively than the haploid strain. Ethanol productivity from raw starch was improved with increased ploidy; the tetraploid strain consumed 150 g/l of raw starch and produced 70 g/l of ethanol after 72 h of fermentation. Our strategy for constructing yeasts resulted in the simultaneous overexpression of genes integrated into the genome and improvements in the practical potential of yeasts.