The main Brazilian lignocellulosic material, sugarcane bagasse, has great energetic potential. This material is composed of three main polymers: cellulose (60-50%), hemicellulose (25-30%) and lignin (25-30%).The development of technologies to use the carbohydrates obtained from the hydrolysis of cellulose (glucose) and hemicellulose (xylose) to bioethanol production is promising and many research groups are making efforts to develop this process.
Native yeasts such as Scheffersomyces stipitis and Spathaspora passalidarum have the ability to utilize xylose for ethanol production. However, the hydrolysis of the lignocellulosic material generates, in addition to sugars, inhibitory compounds (carboxylic acids, furans, phenols and inorganic salts) that changes the metabolism of the microorganisms involved in the bioethanol production.
In this work, the impact of acetic acid, furfural, 5-hydroxymethylfurfural and vanillin was evaluated on cell growth, sugar consumption and ethanol production in the metabolism of S.stipitis and S. passalidarum. The results have shown that acetic acid is the most severe inhibitor for both yeasts and that the metabolism of sugar consumption and ethanol production of S. stipitis is more resistant than S. passalidarum in the presence of inhibitors studied.