Azolla Caroliniana As a Bio-Ethanol Feedstock

Azolla caroliniana is a rapid-growing, resilient, easy to grow water fern that is being used all over there world as a regenerative fertilizer and animal feedstock. This widely utilized plant offers an opportunity for developing nations to produce bio-products or bio-fuels from a dormant form of energy while maintaining the current uses of the plant. The purpose of this study is to deconstruct the carbohydrates in Azolla to monosaccharides and evaluate the feasibility of upgrading these monomers into bio-products. By deconstructing the carbohydrate portion of the plant, the remains would be nitrogen and nutrient dense allowing the waste of the process to serve the current use of Azolla use. Three different methods were used to perform the carbohydrate deconstruction, 10% (w/w) hydrochloric acid, 10% (w/w) sulfuric acid, and an optimized enzyme mixture; the hydrolysate was then evaluated for ethanol production yields using a strain of Saccharomyces cerevisiae, JAY 270. The results showed that, while all treatments released sugars, the hydrochloric acid released the most with 120.6 ± 8.0 milligrams of fermentable sugars per gram of dry biomass. The sulfuric acid hydrolysate yielded the highest yields of ethanol with 0.392 ± 0.06 grams of ethanol per gram of fermentable sugar; the acid treatments produced ethanol while the enzymatic treatments did not. In conclusion, the sulfuric acid process path yielded the most ethanol.