The Potential of Using Macroalgae Biomass to Harvest Microalgae for Lipid and Bioethanol Production

Microalgae harvesting is identified as one of the main challenges in microalgae biofuel production. This is due to the small cell size of microalgae and appeared relatively dilute in cultivate medium. This study was aimed to investigate the harvesting process of microalgae using macroalgae (seaweed) via adsorption. The macroalgae species screened were Kappaphycus alvarezii sp (elkhorn sea moss), Undaria pinnatifida (wakame) and Saccharina angustata (kelp). From the screening process, Undaria pinnatifida (wakame) was identified as the potential seaweed as it exhibited the highest harvesting efficiency of Chlorella vulgaris. Further investigations were conducted to further study different parameters to enhance the harvesting efficiency of microalgae. Based on the studied parameters, the optimum conditions to harvest the microalgae using macroalgae were 4.0 g of macroalgae biomass, pH of the medium at 11 and harvesting duration of 18 hours. In addition, the optimized sample was found to contain 25 of lipid, which can be converted to biodiesel. The lipid extracted sample was further used to produce bioethanol with a concentration of 0.286 g/L. Overall, the study showed that both lipid and bioethanol can be simultaneously produced from microalgae harvested using macroalgae as an adsorbent. © 2021 by Nova Science Publishers, Inc.