【摘要】 添加α 亚麻酸作为底物 ,经半乳糖诱导 ,在含有少根根霉Δ6 脂肪酸脱氢酶基因的酿酒酵母总脂肪酸中检测到十八碳四烯酸的生成 ;同时添加亚油酸和α 亚麻酸时 ,检测到γ 亚麻酸和十八碳四烯酸生成 ,而且十八碳四烯酸的含量是γ 亚麻酸含量的 3 81倍 ,表明在酿酒酵母中少根根霉Δ6 脂肪酸脱氢酶不仅能催化α 亚麻酸生成十八碳四烯酸 ,而且偏好n 3途径中的底物α 亚麻酸。同样 ,在改变少根根霉Δ6 脂肪酸脱氢酶基因的转译起始密码子周边序列后所构建的转基因酵母中 ,也得到类似的结果 ,而且各种目的脂肪酸的含量均有明显提高更多还原

【Abstract】 The transgenic Saccharomyces cerevisiae YRAD6 containing Rhizopus arrhizus △ 6-fatty acid desaurase gene was induced by 2% galactose, supplemented with 0.5mmol/L α-linolenic acid as substrate. GC analysis of the total fatty acids showed a novel peak corresponding to the standard of octadecatetraenoic acid methyl ester was detected, which was further demonstrated by GC-MS analysis. With the same method, γ-linolenic acid and octadecatetraenoic acid were detected in the total fatty acids of the yeast after supplementing linoleic acid and α-linolenic acid at the same time. The content of octadecatetraenoic acid was 3.81 times higher than that of γ-linolenic acid. The results indicated that Rhizopus arrhizus △ 6-fatty acid desaurase in the transgenic yeast catalyzed the conversion of α-linolenic acid to octadecatetraenoic acid with n-3 substrate preference. Similar results were obtained using the yeast YRAD6-1 transformed by the same gene with modification of the sequences flanking AUG codon, and the content of γ-linolenic acid and octadecatetraenoic acid was increased accordingly.更多还原