甜菜碱脂在14种海洋微藻中的分布研究

Distribution of betaine lipids in 14 species of microalgae

采用超高效液相色谱−四极杆−飞行时间质谱联用分析系统(UPLC-Q-TOF MS),对4个微藻门中的14种微藻的甜菜碱脂的分子组成及其相应脂肪酸的组成及分布进行分析。结果表明:在14种微藻中共鉴定出133种甜菜碱脂,包括53种DGCC、41种DGTS和39种DGTA。其中甲藻和定鞭藻中主要的甜菜碱脂种类为DGCC,绿藻中主要的甜菜碱脂种类为DGTS;而在硅藻中的甜菜碱脂主要包括两种:中心硅藻纲中为DGCC,羽纹硅藻纲中为DGTA。此外,不同微藻中甜菜碱脂脂肪酸组成差异仅限制在门或纲的水平上,在较低的分类水平上差异不明显。硅藻门、甲藻门和定鞭藻门中均含有DGCC,其脂肪酸链的组成均含有C14−C18的脂肪酸以及C20和C22的多不饱和脂肪酸,但是甲藻的C14−C18脂肪酸链为饱和的,而C19奇数碳原子的脂肪酸链仅在硅藻中发现。认为海洋微藻甜菜碱脂的研究可以为海洋微藻化学分类学以及缺磷极性脂类的生理、生态作用和功能特性研究提供重要参考依据。

The qualitative and quantitative analyses on betaine lipids of microalgae were conducted by means of the quadrupole flight time ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-Q-TOFMS)using electron spraying ionization.As a result,133 betaine lipids including 53 DGCC,41 DGTS and 39 DGTA were identified from 14 species of microalgae in four major phyla.DGCC was the dominant betaine lipid in dinoflagellates and haptophytes,while DGTS was the main betaine lipid in chlorophytes.There were two main types of betaine lipid in diatoms:DGCC in centric diatom and DGTA in pennate diatom.The differences of fatty acid of betaine lipid in marine microalgae were only observed at the phyla and class levels,but at lower taxonomic levels the differences were less stable.DGCC existed in diatoms,dinoflagellates and chlorophytes,which contained C14−C18 saturated and unsaturated fatty acids and C20 and C22 polyunsaturated fatty acids.The difference in DGCC is that saturated C14−C18 fatty acids existed in dinoflagellates,while the fatty acids of odd carbon numbers C19 occurred only in diatoms.The results of description and molecular characterization of betaine lipid in microalgae can be served in future investigation in chemotaxonomy,physiology,ecological role of microalgae and functional properties of these phosphorous-lacking polar lipids.