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Safety assessment of genetically engineered yeast and breeding of non-toxigenic industrially used yeasts

基因工程酵母的安全性评价及无毒工业用酵母的选育

基本信息

批准号：
07556091
负责人：
MURATA Kousaku
金额：
$ 0.38万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07556091/
关键词：
Transformed Biotechnological food Fermentation Recombinant technique Safety assessment 安全性

项目摘要

The safety of genetically engineered yeast cells was assessed by determining the change in cellular level of methylglyoxal (MG), a typical toxic ketoaldehyde biosynthesized from dihydroxyacetonephosphate by an action of methylglyoxal synthase (MGS). The following results were obtained. (1) when the cells of Saccharomyces cerevisiae transformed with glycolytic enzyme genes (phosphoglucose isomerase, phosphofructokinase and triosephosphate isomerase genes) were incubated in fermentation conditions with large amount of glucose, MG was accumulated in cells at a mutagenic level. (2) The enzymatic study indicated that MGS was entirely responsiblefor the observed accumulation of MG.(3) The deficiency of MGS dramatically lowered the cellular MG level. From these results, the inspection of MG fluctuation in genetically engineered yeast cells is necessary for the safety utilization of the created yeast in practical fermenta-tion processes.The physiological function of MGS was also studied in rel … More ation to the yeast sporulation. The activity of the enzyme was closely related to the sporulation capability of Sake yeasts. The finding was applied to the Sake yeast cells that show no sporulation capability. The removal of MG resulted in the marked increase in sporulation efficiency of Sake yeast and provided means for molecular breeding by hybridization. We were awarded a "Eda prize" from Japan Society of Fermentation and Bioengineering in 1995.The safety assessment was extended to the genetically transformed potato with soybean glycinin gene. The expression level of glycinin was about 1% of the total potato protein. The levels of lipid, carbohydrate, ash, fiber, vitamin, and fatty acids were almost the same as those of control (transformed potato with a vector or non-transformed natural potato). However, transformed potato with a vector or the vector habouring giycinin gene showed increased level of glycoalkaroids (solanin and chakonin) and the level reached 1.5-2 fold of the control. The results indicated that the suitable combination of vector and plant to be transformed is important in creation transgenic plant and/or genetically engineered foods. Less

通过测定丙酮醛（MG）细胞水平的变化来评估基因工程酵母细胞的安全性，MG是一种典型的有毒酮醛，通过丙酮醛合酶（MGS）的作用由二羟基丙酮磷酸生物合成。获得了以下结果。(1)当用糖酵解酶基因（磷酸葡萄糖异构酶、磷酸果糖激酶和磷酸丙糖异构酶基因）转化的酿酒酵母细胞在含有大量葡萄糖的发酵条件下孵育时，MG以诱变水平在细胞中积累。(2)酶的研究表明，MGS是完全负责所观察到的MG的积累。(3)MGS的缺乏显著降低了细胞MG水平。因此，检测基因工程酵母细胞中MG的波动是保证工程酵母在实际发酵过程中安全使用的必要条件，并对MGS的生理功能进行了相关研究 ...更多信息对酵母孢子形成的影响。该酶的活性与清酒酵母产孢能力密切相关。这一发现适用于没有孢子形成能力的清酒酵母细胞。MG的去除使清酒酵母产孢效率显著提高，为杂交育种提供了手段。1995年获得日本发酵与生物工程学会授予的“Eda奖”。大豆球蛋白的表达量约占马铃薯总蛋白的1%。脂质、碳水化合物、灰分、纤维、维生素和脂肪酸的水平几乎与对照（用载体转化的马铃薯或未转化的天然马铃薯）的水平相同。然而，用载体或含有大豆球蛋白基因的载体转化的马铃薯显示糖基生物碱（茄宁和chakonin）的水平增加，并且水平达到对照的1.5-2倍。研究结果表明，载体与被转化植物的合理组合对转基因植物和/或转基因食品的生产具有重要意义。少