摘要:
The neutral lipid (NL) accumulation ofChlorella pyrenoidosa during the mixotrophic growth was studied by using sodium acetate as the organic carbon source and Nile-Red three dimensional fluorescence-regional volume integration to determine the NL content. The differences of biomass productivity, total lipid productivity, and fatty acids of lipids between mixotrophic and autotrophic culture were also investigated. The results showed thatC. pyrenoidosa entered the logarithmic growth phase immediately and grew fast after sodium acetate adding, with the NL accumulation simultaneously being triggered. The concentration of 5g/L sodium acetate could not only promote the microalgal growth and the continuous NL accumulation, but also avoid the environmental stress caused by the excessive organic carbon to algae. After 12-day cultivation, the NL content per cell, biomass production, and total lipid productivity were 4.5, 2.1, and 3.1times those of the autotrophic control samples, respectively. Under the dosage of 5g/L sodium acetate, the fatty acids of lipid mainly consisted of saturated fatty acid C16:0 (22.42%) and unsaturated fatty acids C18:1 (31.58%) and C18:2 (10.89%).%以醋酸盐作为蛋白小球藻兼养生长中的有机碳源,采用尼罗红三维荧光-区域体积积分法测定中性脂含量,研究了蛋白小球藻生长过程中的中性脂积累规律,分析了兼养和自养条件下生物量产率、总脂产率以及油脂的脂肪酸组成差异.结果显示,加入醋酸钠后,蛋白小球藻即进入对数增长期,生长迅速,且同时启动中性脂的积累.5g/L醋酸钠既能促使藻细胞生长和中性脂的持续积累,又能避免过高的有机碳源所带来的环境胁迫,培养12d后,单位细胞中性脂含量达到自养条件下对照样的4.5倍,生物量和总脂产率分别是对照样的2.1倍和3.1倍.5g/L醋酸钠作用下,油脂脂肪酸以饱和脂肪酸C16:0(22.42%)和不饱和脂肪酸C18:1(31.58%)、C18:2(10.89%)为主.