三角褐指藻(Phaeodactylum tricornutum)油脂富集培养的研究

Study on lipid accumulation culture of microalgae Phaeodactylum tricornutum

探讨了营养盐铁、硅及植物激素脱落酸(ABA)单因子对三角褐指藻(Phaeodactylumtricornutum)的生长、油脂含量(%干重)及油脂产量的影响.采用光密度值OD_(450)评价微藻的生长状况,以溶剂浸提法提取油脂.结果表明:(1)铁处理组中,铁浓度在0～46.57umol/L范围内时,藻的生长速率随铁浓度提高而增大;铁浓度为11.64μmol/L时,油脂含量达30%,高于其它铁浓度培养;当铁浓度为11.64μmol/L时,油脂产量最高——是无铁培养的2.8倍;(2)硅处理组中,低含量硅盐(4.6μmol/L)不仅促进了藻的生长而且提高了油脂含量,油脂产量比高含量硅盐(42.6μmol/L)培养提高了40%;(3)ABA处理组中,1 mg/L ABA不仅促进了藻的生长而且提高了油脂含量,油脂产量比对照提高了50%;5 mg/L ABA虽提高了油脂含量但却抑制了藻的生长,油脂产量和对照相当;15 mg/L ABA抑制了藻的生长、降低了油脂含量.用气相色谱分析微藻的脂肪酸组成,结果显示:1 mg/L ABA明显影响了三角褐指藻的脂肪酸组成,以高产量油脂(4.6μmol/L硅盐、1 mg/L ABA培养)为原料制备出的生物柴油的质量将会提高.

Effects of iron,silicate and abscisic acid on growth, lipid content（%dry weigh）and lipid yield of microalgae Phaeodactylum tricornutum were investigated. Optical density OD450 was used to evaluate the growth of P. tricornutum, microalgae lipid was extracted by solvent extraction method. The results showed that.. （1）for the iron-treated experiment, the growth increased with the iron concentration increasing from 0 to 46.57 μmol/L; when the iron concentration was 11.64μmol/L,lipid content reached 30%, which was higher remarkably than that of the other iron concentrations, the maximum lipid yield was harvested at 11.64 μmol/L,which was 2.8 times of the control; （2）for the silicate-treated experiment, the growth and lipid content at 4.6 μmol/L silicate were both higher than that of 42.6μmol/L silicate, lipid yield was 40% higher than that of 42.6μmol/L silicate;（3）tor the ABA-treateu expenment, 1mg/L ABA promoted both the growth and lipid accumulation, lipid yield was 50% higher than the control; 5 mg/L ABA promoted the growth while inhibited lipid accumulation, lipid yield was equivalent to the control; all the parameters decreased at 15mg/L ABA. The fatty acids compositions were analyzed by GC. The results showed that 1mg/L ABA affected significantly the fatty acids compositions, the lipid yield increased with higher quality of the microalgae biodiesel.