Fungal pretreatment as a sustainable and low cost option for bioethanol production from marine algae

Marine algae are promising alternative feedstocks for bioethanol production since they are fast growing and do not compete with food crops for land. However, the commercial viability of bioethanol production from marine algae is limited by the high cost of the pretreatment required to break down the cell wall and the high cost of nitrogen supplements used during fermentation. Development of alternative pretreatment and nutritional supplementation strategies is therefore crucial to the development of economically viable methods for producing these third generation biofuels. This research develops a novel method for fungal pretreatment of marine macroalgae. The method is both an effective pretreatment capable of breaking down the complex algae cell wall, and allows for fungal biomass to be recovered from the pretreatment stage and used as a nutrient supplement during fermentation. The study demonstrates that fungal pretreatment prior to enzyme hydrolysis increased sugar yields 2.3 fold compared to untreated algae, and nutrient supplementation using the recovered fungal biomass increased ethanol yields by up to 38.23%. This data suggests that the use of fungi for pretreatment and nutrient supplementation could greatly increase the economic viability of production of these third-generation biofuels.