过表达甘油激酶三角褐指藻藻株富集油脂的研究

Study on lipid accumulation of Phaeodactylum tricornutum strain overexpressing glycerol kinase

摘要:

为了得到高产并符合生物柴油标准的微藻油脂的藻株，本文研究了在外源甘油存在的情况下野生型（WT）三角褐指藻（Phaeodactylum tricornutum），甘油激酶过表达藻株（GKOE）以及甘油激酶RNA干扰藻株（GKRNi）在添加浓度为20 mmol/L外源甘油的培养基中的生长情况、油脂产量以及脂肪酸组成.结果显示：（1）甘油兼养的GKOE藻细胞浓度可达到2.23×107个/mL，明显高于甘油兼养的WT的1.79×107个/mL和GKRNi的1.78×107 个/mL;（2）甘油兼养的GKOE油脂含量可达到31.73%，比甘油兼养的WT和GKRNi分别高了27.20%和26.63%;（3）尼罗红染色显示甘油兼养的GKOE荧光强度比甘油兼养的WT和GKRNi分别高16.26%和17.83%；（4）甘油兼养的GKOE总脂肪酸产量可达到0.052 mg/mL,比甘油兼养的WT和GKRNi高了36.84%和10.64%，说明其油脂适合于生物柴油开发.

Abstract:

In order to obtain high-yield algae strains that meet biodiesel standards, the growth, lipid yield and fatty acid composition of Phaeodactylum tricornutum wild-type(WT), Phaeodactyllum tricornutum with glycerol kinase overexpression (GKOE) and glycerol kinase RNA interfered(GKRNi), which were cultured in a medium supplemented with 20 mmol/L exogenous glycerol, were investigated. The results showed that: (1) the cell concentration of GKOE in the medium with exogenous glycerol could reach 2.23×107 /mL, significantly higher than WT(1.79×107 /mL) and GKRNi(1.78×107 /mL) in the medium with exogenous glycerol; (2) the lipid content of GKOE in the medium with exogenous glycerol was up to 31.73%, which was much higher than WT(27.20%) and GKRNi(26.63%) in the medium with exogenous glycerol; (3) the fluorescence intensity of GKOE in the medium with exogenous glycerol was 16.26% and 17.83% higher than WT and GKRNi in the medium with exogenous glycerol by Nile red staining, respectively; (4) the total fatty acid yield of GKOE reached 0.052 mg/mL, which was 16.26% and 17.83% higher than WT and GKRNi in the medium with exogenous glycerol, and suitable for biodiesel development.