富油新绿藻在不同培养期油脂的脂肪酸组成

摘要

In order to understand the mechanism of fatty acid biosynthesis of Neochloris (Ettlia) oleoabundans through observation of lipid contents and fatty acid composition at different stages in batch cultivation, N. (E.) oleoabundans was cultured with a modified SE medium and under nitrogen deficiency stress strategy. The microalgal cells were collected at growth phase, stationary phase, decline phase and nitrogen deficiency stage. The lipids were extracted by Folch method, the oil yields were calculated gravimetrically, and the fatty acid compositions of the extracted lipid were analyzed by GC. The results showed that the lipid content of microalgal cells was increased with prolonging of cultivation and it reached at the maximum of 28.99% under nitrogen deficiency stage; significant changes was observed in the fatty acid composition, i.e., C18:1 from 24% to 44%, C18:2 from 26.84%to 19.85 and C18:3 from 12.74% to 4.75% from growth stage to nitrogen deficiency stage. It can be concluded that lipid accumulation occurred in the later stage of cultivation and nitrogen deficiency and the significant changes occurred in compositions of some fatty acids.%用改良SE培养基培养富油新绿藻(Neochloris oleoabundans),用缺氮改良SE培养基培养处于稳定期后期的藻细胞3 d,分别收集处于生长期、稳定期、衰亡期和缺氮胁迫状态的藻细胞,用Folch法提取藻细胞油脂,以质量法计算油脂产率,用气相色谱法测定脂肪酸组成.结果表明,富油新绿藻随着培养期延长油脂含量提高,在缺氮胁迫状态下藻细胞油脂质量分数达28.99%;随着细胞油脂含量的增加,油脂脂肪酸组成也发生变化,从生长期到氮缺乏胁迫状态油酸质量分数由24%增至44%,而亚油酸质量分数由26.84%降至19.85%,亚麻酸质量分数由12.74%降至4.75%.富油新绿藻在分批培养后期和氮缺乏而碳源充足的条件下可积累油脂,而在油脂积累阶段油脂的脂肪酸组成亦不同.