水酶法提取微藻油脂的研究

Research on the Extraction of Microalgae Lipids by Aqueous Enzymatic Process

以微拟球藻和小球藻两种富油微藻为研究对象,研究了酸碱预处理,采用水酶法联合应用对两种微藻细胞酶解破壁后微藻油脂提取率的影响,并考察了萃取溶剂对油脂提取率和微藻油脂组成的影响。结果表明,在较低的温度下,通过对两种微藻碱预处理,采用商业化的纤维素酶、果胶酶和蛋白酶复合酶对微拟球藻进行酶解,而小球藻用纤维素酶酶解,然后使用双溶剂体系进行萃取,微拟球藻的油脂提取率可达95%以上,小球藻油脂提取率也可达77%以上。对提取油脂进行分析可知,采用不同双溶剂体系得到的微藻油脂组成有所不同,采用正己烷-乙醇为溶剂萃取的微藻油脂中可皂化物的含量相对较高。微藻油脂中的多不饱和脂肪酸中含有丰富的C20以上的长链脂肪酸,特别是二十碳五烯酸(EPA)、花生四烯酸(ARA)等对人体有益的营养成分含量较高,体现了微藻养殖的产业前景。本研究的方法和结果可对促进微拟球藻和小球藻高效节能的油脂提取参考,为微藻产业化应用提供技术支持。

Two kinds of oil-rich microalgae including Nannochloropsis sp. and Chlorella vulgaris were chosen as the study objects. The effects of acid-base pretreatment and aqueous enzymatic treatment on the lipid extraction yield after cell wall enzymatic hydrolysis were investigated. Furthermore, the effects of extraction solvents on the extraction yield and the composition of microalgae lipid were also studied. The results showed that the combination of alkaline pretreatment, subsequent enzymatic treatment and then dual solvent system extraction was most effective process for the lipid extraction from the two kinds of microalgae. Under mild reaction conditions, the lipid yield of Nannochloropsis sp. with commercial complex enzymes and Chlorella vulgari with cellulase reached more than 95% and 77%,respectively. In addition, it was found that the content of saponifiable lipid extracted by n-hexane-ethanol was higher than that obtained by trichloromethane-ethanol, which was beneficial to the further synthesis of microalgae biodiesel.In addition, it can be found that the microalgae oil contains abundant C20 long chain fatty acids, such as EPA, ARA and other nutrients by analyzing the fatty acids, indicating the promising future of microalgae cultivation. The method and results of this study provide a reference for promoting efficient and energy-saving lipid extraction from microalgae Nannochloropsis sp. and Chlorella vulgari, and provide technical support for microalgae industrial application.