硬脂酰-辅酶A脱氢酶基因在食品级乳酸菌中的表达

Heterologous expression of stearoyl-CoA desaturase-1 in Lactococcus lactis NZ3900

摘要:

为了实现硬脂酰-辅酶A脱氢酶1编码基因在乳酸乳球菌中的表达，采用PCR技术扩增获得人类scd1的编码序列。Nco I 和Xba I双酶切后定向插入到食品级表达载体pNZ8149中，构建表达载体pNZ8149-scd1。电转化乳酸乳球菌NZ3900，经菌落PCR和测序鉴定scd1基因成功插入到乳酸乳球菌中。在乳链菌肽诱导下进行scd1的表达，转化株提取脂肪酸，进行脂肪酸含量的气相色谱分析。结果显示，SCD1转化菌株中的C16∶1n-7和C18∶1n-7脂肪酸组分比转化pNZ8149的对照组乳酸菌分别提高了92％~169％和53％~127％。文中以scd1基因为例，尝试并证明了脂肪酸脱氢酶类基因能够在食品级乳酸菌中有效表达，为后续研究奠定了基础。

Abstract:

The possibility of heterologous expression of human Stearoyl-CoA Desaturase (scd1) was investigated. The scd1 encoding sequence was inserted into the pNZ8149 to generate the pNZ8149-scd1 expression plasmids. Then we introduced the pNZ8149-scd1 construct into the Lactococcus lactis NZ3900 to investigate its enzyme activity. The results show that heterologous expressed SCD1 enzyme resulted in a 92%–169% increase in the C16:1n-7 and a 53-127% increase in the C18:1n-7 (P<0.05). The SCD1 enzyme was capable of producing n-7 fatty acids in Lactococcus lactis efficiently. It also suggests that the fatty acid desaturases can be heterologous expressed in Lactococcus lactis to produce the helpful fatty acids.