有机碳源对三角褐指藻生长、胞内物质和脂肪酸组分的影响

研究了3种有机碳对三角褐指藻生长、胞内物质和脂肪酸组分的影响。结果表明, 三角褐指藻具有利用有机碳进行兼养生长的能力, 生长速率加快, 倍增时间缩短, 生物量显著提高, 100 mmol/L甘油兼养的生物量最高(713 mg/L), 是自养(460 mg/L)的1.60倍, 乙酸钠和葡萄糖兼养的生物量分别是自养的1.28倍和1.21倍。兼养下蛋白质含量较自养明显下降, 碳水化合物和总脂含量高于自养, 乙酸钠和甘油兼养的总脂含量分别是自养的1.43倍和1.20倍, 葡萄糖兼养的总脂含量与自养无明显差异。3种有机碳兼养的饱和脂肪酸和单不饱和脂肪酸占总脂肪酸的比例增大, 多不饱和脂肪酸比例降低, EPA(eicosapentaenoic acid)比例降低, 乙酸钠兼养的胞内EPA含量(6.23%)和产量(36.59 mg/L)均高于自养, 分别是自养的1.10倍和1.40倍, 甘油和葡萄糖兼养的EPA含量和产量均低于自养。

Effects of organic carbon source on growth, biochemical components and fatty acid composition of Phaeodactylum tricornutum

We examined the effects of three organic carbon sources on mixotrophic growth, biochemical components and fatty acid composition of Phaeodactylum tricornutum. Mixotrophically, P. tricornutum grew faster and had shorter doubling time. The biomass of P. tricornutum was greatly enhanced under mixotrophic condition with its highest biomass of 713 mg/L after 16 days, in medium containing 100 mmol/L glycerol. This was 1.60-fold of that obtained under autotrophic condition. The biomass during mixotrophic culture with 100 mmol/L glucose and 100 mmol/L acetate was 1.28-fold and 1.21-fold of that obtained under autotrophic condition, respectively. Compared with autotrophic condition, the content of soluble protein decreased obviously, whereas the content of soluble carbohydrate and total lipid increased. The content of lipid during mixotrophic culture with 100 mmol/L acetate and 100 mmol/L glycerol was 1.43-fold and 1.20-fold of that obtained under autotrophic condition, respectively. There was no difference between lipid content of mixotrophic growth with 100 mmol/L glucose and that of autotrophic condition. The eicosapentaenoic acid (EPA) content and yield was 6.23% and 36.59 mg/L during mixotrophic culture with 100 mmol/L acetate. These were 1.10-fold and 1.40-fold of that obtained under autotrophic condition, respectively. The EPA content and yield with glycerol and glucose were lower than that obtained under autotrophic condition. These results indicated that mixotrophic cultivation with acetate was beneficial to produce EPA.