Butanol production by Clostridium species from macroalgal substrate

Abstract

• Our study focused on the importance of macroalgal feedstock especially Sargassum latifolium for biofuels production especially biobutanol production. • Cellulose, hemicellulose, lignin, and minerals contents for Sargassum latifolium were determined. The results revealed that S. latifolium has high carbohydrates content (40.84%) compared with lignin content (8.95%) which makes it easy for pretreatment, hydrolysis, and production of high total reducing sugars. In addition to, S. latifolium was rich with minerals (P, Na, K, Mg, Cd, Zn, Cu, Ni, Fe, and Pb). • Our substrate (S. trifolium) was cut and milled before hydrolysis process. • Different hydrolysis processes (chemical and biological) were carried out. The chemical hydrolysis process by sulfuric acid which gave the greatest TRS (7.68 g/L) compared to hydrochloric acid (5.48 g/L). Our results showed that the chemical hydrolysis process was more effective for the small size biomass compared to the big one. • The combination between the base treatment (KOH) and the acid hydrolysis (HCl) was more effective than combination between NaOH treatment and H2SO4 hydrolysis. • The biological hydrolysis process was carried out by using different fungal strains (Trichoderma viride F94; T. reesei F68; Aspergillus terreus F98, A. niger F66). Trichoderma viride F94 was the most promising fungal strains for total reducing sugars production than other fungal strains.