ABSTRACT

The high levels of carbohydrates in some microalgae make them a promising feedstock for bioethanol production. The pretreatment of microalgal biomass is one of the most important stages to improve cell disruption for increasing the accessibility to the intracellular compounds. The isolation and identification of newly isolated microalgae that produce high biomass and carbohydrate production were done in this research. Among six isolates, Chlorella S-4 and Picochlorum D-8 showed the highest specific growth rates of 0.189 and 0.215 (µ day⁻¹), respectively, from which the former showed a suitable self-precipitation property. A combination of cell disruption methods, including acid-thermal, acid-thermal/sonication bath, and acid-thermal/freeze & thaw pretreatment was applied to disrupt the cell wall of isolated microalgae on a laboratory scale. The effectiveness of cell disruption methods was evaluated based on total carbohydrate measurement. The maximum carbohydrate content of 22% and 27% of dry weight with the productivity of 7 and 6 mg/L/d was obtained from Chlorella S-4 and Picochlorum D-8, respectively, using acid-high thermal pretreatment (121^°C for 20 min). This study is trying to demonstrate the Persian Gulf native microalgae potential for possible bioethanol production.

摘要

一些微藻中的高碳水化合物含量使它们成为生产生物乙醇的有前途的原料。微藻生物质的预处理是改善细胞破坏以增加对细胞内化合物的可及性的最重要阶段之一。本研究对新分离的产生高生物量和碳水化合物产量的微藻进行了分离和鉴定。在六种分离物中，小球藻S-4 和小球藻D-8 的比生长率最高，分别为 0.189 和 0.215 (µ day ^-1), 从中前者表现出合适的自沉淀性能。采用酸热、酸热/超声浴和酸热/冻融预处理等细胞破碎方法的组合，在实验室规模上破碎分离的微藻的细胞壁。基于总碳水化合物测量评估细胞破碎方法的有效性。使用酸高热预处理（121 ° ^C 20 分钟）。这项研究试图证明波斯湾本地微藻可能生产生物乙醇的潜力。