The alcoholic fermentation of substrates rich in free soluble sugars is well known and has been industrially developed. However, the production of second-generation ethanol from lignocellulosic biomass, which is abund...The alcoholic fermentation of substrates rich in free soluble sugars is well known and has been industrially developed. However, the production of second-generation ethanol from lignocellulosic biomass, which is abundantly available worldwide, remains under development. The aim of this study was to evaluate the possibility of using the Musa cavendischii banana tree pseudostem as a substrate for alcoholic fermentation. Hydrolisis methods using dilute sulfuric acid （1% and 2% H2SO4; 15 and 30 min; 90 ℃, 100 ℃ and 120 ℃） and enzymes （pH 5.5; and 45 ℃ for 24 h reaction time） were evaluated both separately and in combination. The effect of chemical pre-treatment of the substrate using 1% and 3% m/m NaOH （120 ℃, 15 min） was verified for both methods. The highest yield coefficient of fermentable sugars from dry biomass （Yrs = 74%） was obtained using enzymatic hydrolysis and pre-treatment with 3% NaOH. Using acid hydrolysis, the maximum yield obtained was 22% （1% H2SO4, 120 ℃, 30 min）. Fermentation of the hydrolysates was satisfactory, and the maximum yield of ethanol formed per unit of substrate consumed, total productivity and efficiency values were 0.35 g, 0.90 g ethanol L^-1·h^-1 and 65.9%, respectively. This demonstrates the utility of banana tree pseudostems in second-generation ethanol production.展开更多
文摘The alcoholic fermentation of substrates rich in free soluble sugars is well known and has been industrially developed. However, the production of second-generation ethanol from lignocellulosic biomass, which is abundantly available worldwide, remains under development. The aim of this study was to evaluate the possibility of using the Musa cavendischii banana tree pseudostem as a substrate for alcoholic fermentation. Hydrolisis methods using dilute sulfuric acid （1% and 2% H2SO4; 15 and 30 min; 90 ℃, 100 ℃ and 120 ℃） and enzymes （pH 5.5; and 45 ℃ for 24 h reaction time） were evaluated both separately and in combination. The effect of chemical pre-treatment of the substrate using 1% and 3% m/m NaOH （120 ℃, 15 min） was verified for both methods. The highest yield coefficient of fermentable sugars from dry biomass （Yrs = 74%） was obtained using enzymatic hydrolysis and pre-treatment with 3% NaOH. Using acid hydrolysis, the maximum yield obtained was 22% （1% H2SO4, 120 ℃, 30 min）. Fermentation of the hydrolysates was satisfactory, and the maximum yield of ethanol formed per unit of substrate consumed, total productivity and efficiency values were 0.35 g, 0.90 g ethanol L^-1·h^-1 and 65.9%, respectively. This demonstrates the utility of banana tree pseudostems in second-generation ethanol production.
