Department of Engineering Science, College of Engineering and Agro-Industrial Technology, University of the Philippines Los Baños, College, Los Baños, Laguna, 4031, Philippines
Department of Environmental Engineering and Energy, Myongji University, 116 Myongji-Ro, Cheoin-Gu, Yongin, Gyeonggi-Do 449-728, Republic of Korea
Macroalgae are a promising option because they can be propagated easily along the seaside thus eliminating the need for land and nutrient resources. Hence, different macroalgae were assessed for their potential in butanol fermentation. In this study, four species of brown macroalgae (Undaria pinnatifida, Laminaria japonica, Ecklonia stolonifera, Hizikia fusiforme, and Sargassum fulvellum) and two species of red macroalgae (Porphyra tenera and Gelidium amansii) were investigated for the production of butanol by Clostridium saccharoperbutylacetonicum N1-4. To hydrolyze the polymeric materials of the algal biomass, dilute acid hydrolysis was carried out using 0.15 M H2SO4 followed by thermal pretreatment at 121°C for 1 h. Using 100 g/L of hydrolyzed brown alga, the highest butanol production (5.51 g/L) was observed for L. japonica. Other brown and red macroalgae did not exceed the butanol production by L. japonica. Moreover, the detoxification of the thermo-chemically pretreated hydrolysate of L. japonica using the activated carbon and overliming method, increased the butanol production by 24.14 and 12.16%, respectively. These results showed that macroalgae could be a promising substrate for butanol fermentation that is cheap, easily propagated, and non-terrestrial and non-food competing.