一种优化Botryococcus braunii-357生物膜油脂的方法

A measure to optimize fatty acids of Botryococcus braunii-357 biofilms

脂肪酸的组成与结构是影响微藻生物柴油物理特性的重要因素。胞外聚合物(EPS)有助于微藻吸附生长和生物膜的形成。为了研究EPS对微藻生物膜油脂含量及脂肪酸组成的影响,对布朗葡萄藻生物膜进行EPS刺激培养,同时设计营养抑制组作为对照。结果显示:抑制组和EPS组的油脂含量分别由16.54%提高至42.2%和51.3%,油脂的中性三酰甘油酯(TAG)占比均达93%左右,饱和脂肪酸分别占55.4%,62.6%,不饱和脂肪酸分别占38.7%,31.0%。不饱和脂肪酸方面,抑制组的油酸分子均为反式结构,EPS组均为顺式结构。用EPS刺激生物膜藻体,所得微藻油的油脂含量、纯度、日产率以及TAG比例都得以提高,油脂脂肪酸组成和品质得到改善。

The compositions and structures of fatty acid are important factors affecting the physical characteristics of microalgae biodiesel. Extracellular polymeric substances contribute to microalgal cells adhesion and growth and formation of biofilms. Based on this reality, Botryococcus braunii-357 biofilm was further stimulating cultured under EPS solution in order to explore its influence on oil contents and fatty acid compositions, and designed nutrient inhibition as a control group. The results showed that oil contents were improved to 42.2% and 51.3%, respectively, among which the neutral triacylglycerol ester（TAG）occupied more than 93%. According to the TAG genealogy, saturated fatty acids were 55.4%, 62.6%, unsaturated fatty acids were 38.7%, 31%, in two cases. Unsaturated fatty acids, such as oleic acid and linoleic acid, oleic acid molecules in nutrient inhibition group were trans-structural, nevertheless, molecules in EPS stimulation group were cis-structural. In conclusion,with the stimulation of extracellular polymeric substances, the oil content, productivity, and ratio of TAG were all increased, fatty acid compositions and quality of microalgae biofilms were considerably improved.