摘要
γ-亚麻酸(γ-Linolenic acid,GLA)是人体所必需且具有多种生理功能的一种重要多不饱和脂肪酸。研究表明,卷枝毛霉等GLA生产菌株中△6-脂肪酸脱饱和酶(△6-Fatty acid desaturase,FAD6)是合成γ-亚麻酸的关键和限速酶,然而GLA是否惟一通过△6-脂肪酸脱饱和酶途径合成则目前还没有报道。作者以卷枝毛霉Mucor circinelloides EIM10 sp.为研究对象,以其FAD6基因的5'端启动子和3'端终止子为同源臂,潮霉素B抗性基因为筛选标记,构建了M.circinelloides EIM10 sp.△6-脂肪酸脱饱和酶FAD6的敲除载体p UMCD6-Hm B,转化进入制备好的原生质体中成功地敲除了FAD6基因,发现FAD6基因缺陷菌株GLA质量浓度比野生型对照菌株降低了50%以上,但GLA并没有完全消失,说明卷枝毛霉生物体内还有其他代谢途径可以将碳源转化为GLA。
γ-linolenic acid （GLA） that is an essential polyunsaturated fatty acid （PUFA） plays a vital role in many metabolic processes. Most related studies showed that delta 6-fatty acid desaturase （FAD6） was an important rate-limiting enzyme for the synthesis of γ-linolenic acid from Mucor circineUoides. However, it has not been reported whether the delta 6- fatty acid desaturase is the only pathway to produce γ-linolenic. In this work,we constructed M. circinelloides EIM10 sp.FAD6 knockout vector pUMCD6-HmB on the basis of pUC18 to study the function of FAD6. The homologous sequences of 5＇ promoter and 3＇ terminator of FAD combined with hygromycin B resistant gene used as the selective marker were connected as the knockout fragment. Then the vector pUMCD6-HmB was transformed into the prepared protoplast of M. circinelloides EIM10 sp. The results showed that FAD6 gene was successfully disrupted and GLA accumulation of the mutant disrupted in FAD6 decrease about 50% compared to the wild type. It can be concluded that FAD6 was essential for GLA production in M. circinelloides but there is probably other ways to accumulate GLA in M. Circinelloides.
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2017年第6期617-624,共8页
Journal of Food Science and Biotechnology
基金
福建省自然科学基金重大项目(2011H6007)
福建省自然科学基金面上项目(2016J01148)
福建省科技计划项目(2014Y2008)
福建省中青年教师教育科研项目(JAT160768)
关键词
Γ-亚麻酸
卷枝毛霉
△6-脂肪酸脱饱和酶
基因敲除
γ-Linolenic acid, Mucor circinelloides, delta 6-fatty acid desaturase, gene knockout
