FATTY ACID ETHYL ESTERS FROM MICROALGAE OF Scenedesmus ecornis BY ENZYMATIC AND ACID CATALYSIS

Microalgae are an indispensable food source for the various growth stages of mollusks, crustaceans, and several fish species. Using a microalgae biomass present in the Amazonian ecosystem (Macapá-AP), we study extraction methods for fatty acid such as solvent extraction (magnetic stirring and/or Soxhlet) and/or hydrolysis (acid and/or enzymatic catalysis) followed by esterification and/or direct transesterification. Extraction of crude triacylglycerides by mechanical stirring at room temperature was more efficient than continuous reflux (Soxhlet). Subsequently, the lipid extract was subject to transesterification with ethanol and CAL-B as a biocatalyst, leading to production of fatty acid ethyl esters (FAEE). Additionally, FAEEs were prepared by hydrolysis of crude triacylglycerides followed by acid-mediated esterification or enzymatic catalysis (lipase). In this case, the type of catalyst did not significantly influence FAEE yields. In the lipid extract, we identified palmitic, linoleic, oleic, and stearic acids with palmitic acid being the most abundant. Our results suggest that enzymatic catalysis is a viable method for the extraction of lipids in the microalga, Scenedesmus ecornis.

微藻是软体动物、甲壳类动物及多种鱼类不同生长阶段不可或缺的食物来源。本研究以取自亚马逊生态系统（马卡帕-AP）的微藻生物质为研究对象，针对脂肪酸提取方法展开探究，涵盖溶剂萃取法（磁力搅拌法和/或索氏提取（Soxhlet））以及水解法（酸催化和/或酶催化），后续辅以酯化反应和/或直接酯交换反应。实验结果显示，室温下通过机械搅拌提取粗甘油三酯的效率，优于连续回流法（索氏提取）。随后，将所得脂质提取物与乙醇在CAL-B作为生物催化剂的条件下进行酯交换反应，制备得到脂肪酸乙酯（FAEE）。此外，本研究还通过先水解粗甘油三酯，再经酸介导酯化反应或酶催化（脂肪酶）的路径制备FAEE。在此路径中，催化剂类型对FAEE产率无显著影响。在该脂质提取物中，我们检测到棕榈酸、亚油酸、油酸及硬脂酸，其中棕榈酸含量最高。本研究结果表明，酶催化法是提取无棘栅藻（Scenedesmus ecornis）脂质的可行方法。