重组解脂亚罗酵母合成菜油甾醇

菜油甾醇是一种具有重要生理活性的植物甾醇。为构建合成菜油甾醇的工程菌株,通过敲除解脂亚罗酵母polf菌株中麦角固醇合成基因ERG5,促进麦角-5,7,24-三烯醇的体内积累,进而表达经密码子优化的非洲爪蟾DHCR7基因,使麦角-5,7,24-三烯醇在DHCR7和polf胞内ERG4的共同催化作用下,转化成菜油甾醇,最后利用GC-MS对重组菌株的发酵产物进行检测分析。结果表明,重组菌株polf-ERG5--DHCR7+(PED)合成菜油甾醇的产量达0.485 mg/g(以细胞干重计)。重组解脂亚罗酵母合成菜油甾醇菌株的成功构建,为生物合成法合成植物甾醇提供了新思路。

Synthesis of campesterol by recombinant Yarrowia lipolytica

Campesterol as one of the phytosterols has important physiological activity. In order to construct engineered strain which could synthesize campesterol, the ergosterol synthesis gene ERG5 was disrupted in Yarrowia lipolytica polf, promoting the accumulation of precursor product ergosta-5,7,24-trienol. Then the codon-optimized DHCR7 gene from Xenapus laevis was expressed. Under the coefficient of DHCR7 and endogenous ERG4 in polf,the ergosta-5,7,24-trienol was transformed into campesterol. The fermentation products of the recombinant strain were analyzed by GC-MS. The results showed that engineered strain which could produce campesterol was obtained, and the maximum yield was 0.485 mg/g( based on dry cell weight). Thus, an engineered strain that could biosynthesize campesterol was successfully constructed, which provided a new way for the biosynthesis of phytosterols.