马尾藻中产不饱和脂肪酸真菌的分离及其脂肪酸组成分析

【背景】随着从鱼类、农作物原料中提取不饱和脂肪酸的成本越来越高,寻找特殊且成本低的提取原料迫在眉睫。海洋环境的特殊性造就了丰富而特有的微生物资源,成为获取产不饱和脂肪酸的新策略。【目的】从湛江徐闻马尾藻中分离筛选产油脂真菌,并对其脂代谢产物进行气相色谱分析(GC)。【方法】通过利用选择性培养基及苏丹黑染色方法从马尾藻中筛选高产油脂真菌,对目标菌进行形态特征、培养特征及ITS序列鉴定,利用GC技术对三氯甲烷-甲醇提取的油脂进行组成成分分析与含油量测定。【结果】共筛选到7株产油脂真菌,其中菌株A17脂肪颗粒大且密集,是一株高产菌株,经形态与基因水平鉴定,确定菌株A17为变红镰孢菌(Fusarium incarnatum)。提取的油脂占细胞干重的24.75%,并且不饱和脂肪酸占总油脂的60.76%,其中油酸与亚油酸分别为32.80%和26.20%。【结论】该研究可为开发马尾藻中产油脂菌株提供理论依据。

Separation of unsaturated fatty-acid producing fungi from Sargassum and analysis of fatty acid composition

Background] A special extracting raw material with low cost is extremely urgent, as the expense of extracting unsaturated fatty acids from fish and crops is growing high. The particularity of ocean environment results in a rich and unique microbial resource, which have been regarded as a new strategy for obtaining unsaturated fatty acids. Objective] The aim was to isolate oil-producing fungi from Scagassum collected from Xuwen Port, Zhanjiang, Guangdong Province, and analyze its fatty acid composition by gas chromatography (GC). Methods] The selective plating medium and method of Sudan Black B staining were used to screen high-yield oil-producing fungi. The target strain was identified by morphological and culture characteristics and analysis of ITS sequences. GC was used to determine the composition and content of the lipids which were extracted by chloroform-methanol. Results] A total of 7 oil-producing fungal strains were screened, among which strain A17 was the high-yield oil-producing fungus with larger lipochondrion. The analysis of morphology and molecular identification of ITS sequence showed that the strain A17 was Fusarium incarnatum. The oil extracted from the strain A17 accounted for 24.75% of the cell dry weight, and unsaturated fatty acid accounted for 60.76% of the total oil content, which oleic acid and linoleic acid were 32.80% and 26.20 %, respectively. Conclusion] This study may provide a theoretical base for the development of oil-producing strains in Scagassum.