一种饵料微藻的脂肪酸甾醇分析及化学分类的探讨

Analysis of fatty acids and sterols in one marine feed microalga and its potential chemotaxonomic significance

对一种重要的未知生物饵料微藻在充气和瓶中静态两种生态条件下进行培养,设计了一种分步衍生化脂肪酸与甾醇的GC/MS连续分析法,对微藻脂肪酸甾醇进行了定性和定量分析,结果表明,这种微藻主要含有丰富的二十碳五烯酸(EPA),C14:0,C16:0,C16:1以及一定量的二十二碳六烯酸(DHA),C22:5(n6)和C18不饱和脂肪酸;共鉴定出11种甾醇组分,主要是24甲基(乙基)胆甾醇,碳数分布从27到30,特别含有甲基巴夫甾醇和乙基巴夫甾醇;可以把这种微藻归到Prymnesiophyceae纲Pavlovales目Pavlovaceae科.通过实例分析证明,脂类分析结果可以作为海洋微藻化学分类学的一个重要依据.

There is an unknown microalga(ZM2020) which has been used widely and proved to be nutritious as feed. In order to evaluate its nutrition value based on fatty acids and sterols, the alga has been cultured in two modes as standing and air bubbling conditions, simultaneous analysis of fatty acids and sterols has been carried out on a gas chromatography mass spectrometer by applying a new step-wise derivetization method. The results indicate that the microalga is abundant in EPA, C14:0, C16:0, C16:1, as well as some conceivable amount of DHA, C22:5(n-6) and C18 unsaturated fatty acids. Eleven C27 to C30 sterols have been identified with major ones including 24-methyl (ethyl)-cholesterol. The existence of unusual sterols of methylpavlovol and ethylpavlovol has been observed unambiguously. Based on the composition analysis of fatty acids and sterols, this alga can be classified into Prymnesiophyceae, Pavlovales, Pavlovaceae. It is also demonstrated here that lipid analysis can be a useful tool for microalgal chemotaxonomy.