培养基限氮和添加钨酸钠对微拟球藻脂肪酸组成的影响

EFFECT OF NITROGEN DEFICIENCY AND SODIUM TUNGSTATE IN MEDIUM ON THE FATTY ACID COMPOSITION OF NANNOCHLOROPSIS OCULATA

微藻的脂肪酸组成与环境条件密切相关。选取微拟球藻(Nannochloropsis oculata)为对象,比较研究了对培养基限氮和添加钨酸钠时,其脂肪酸组成的变化。结果表明:培养基限氮时,16:0、16:1、和18:1占总脂肪酸的比例均显著提高,其中16:0和18:1均在限制96h达到最高值,分别提高了24.77%和95.27%,而20:4和20:5则显著降低。添加钨酸钠培养时,16:0、16:1、和18:1占总脂肪酸的比例均显著提高。在钨酸钠浓度为0.1mmol/L时,与对照组相比,18:1含量提高了1.13倍。该结果与培养基限氮培养时一致。因此,添加钨酸钠可实现氮限制。本研究旨在通过改变培养条件,探索微藻生物量积累后富集油脂的可能性,为微藻生物柴油大规模生产提供理论基础。

Environmental factors play an important role in determining the fatty acid composition of microalgae.The changes of the fatty acid composition of Nannochloropsis oculata was studied at the conditions of nitrogen deficiencies and supplementing different sodium tungstate concentrations in medium.The results showed that at the conditions of nitrogen deficiencies the proportion of 16：0,16：1,and 18：1 to the total fatty acids significantly increased,including 16：0 increased by 24.77% and 18：1 by 95.27% when deficiency time is 96h while the content of 20：4 and 20：5 decreased markedly.When adding of sodium tungstate in medium,the proportion of 16：0,16：1,and 18：1 to the total fatty acids significantly increased with the maximum increase occurred in 18：1（113%） at 0.1mmol/L sodium tungstate.The result is consistent with that of nitrogen deficiency.Sodium tungstate can serve as the scavenger of nitrogen in medium.This study will provide a theoretical basis for the production of microalgal biodiesel after accumulation of biomass.