BIO-ETHANOL PRODUCTION FROM Desmodium triflorum (L.) USING Saccharomyces cerevisiae

Abstract

Bio-ethanol is a clear liquid alcohol that is made by the fermentation of different biological materials. it is being considered as a potential liquid fuel due to the limited amount of natural resources. This study was undertaken with the objective of producing bio-ethanol from leaves of Desmodium triflorum by fermenting for 16 days. The leaves were first pre-treated with dilute sulfuric acid to ease the hydrolysis of lignocelulosic material and incubated in different substrate concentrations(10gm, 20gm , 30g and 40gm) inoculated with 0.5 and 1% of yeast concentration.Bio- ethanol production, total reducing sugar and cell density were measured at every four days interval of fermentation period, i.e., on the 4th day, 8th day, 12th and 16th days of fermentation. Results showed tha tBio- ethanol production was observed starting from the fourth day of fermentation in all substrate and inoculum levels. The higher amount of ethanol produced was found to be 20.50±0.47ml and this was observed when 20g substrate was mixed with 1% inoculum. With increasing concentration of substrate, ethanol production increased to 20.50±0.47ml at 20g, but thereafter appeared to decrease. Reducing sugar apeared to subsequently reduced with increasing days of fermentation. Values showed that, reducing sugar concentration was found to be highest on the 4th day of fermentation, which is 20.46±0.42gm/ml in 20g Desmodium triflorum mixed with 1% yeast, but progressively decreased with increasing fermentation time. Cell density showed similar trend with that of ethanol production. Cell density increased with increasing days of fermentation compared to the 4th days of fermentation, but the result peaked on the 8th days of fermentation into 3.65±0.08 mg/ml and declined after that. In conclusion, this study showed that it is possible to produce bio-ethanol from Desmodium trifiorum, and optimal concentration is found to be 20g substrate incoculated with 1% yeast for effective fermentation.