YEAST CULTIVATION FOR SINGLE-CELL PROTEIN PRODUCTION USING THE CARBOHYDRATE HYDROLYSATE OF STEAM-EXPLODED EUCALYPTUS WOOD

Abstract

This study was aimed at producing single-cell (SCP) protein from the carbohydrate hydrolysate of steam-exploded eucalyptus (Eucalyptus urophylla) wood. Two yeast strains including Saccharomyces cerevisiae and Candida utilis 2.587 were used for batch fermentation. Results showed that the total reducing sugars (TRS), glucose and xylose in hydrolysate had concentrations of 17.52, 10.71, and 4.30 g·L-1, respectively.During fermentation, yeast strains of S. cerevisiae and C. utilis 2.587 used monosaccharides sequentially, and secondary growth occurred. The yeast biomass contained 43.59% crude protein and was rich in all essential amino acids such as lysine, leucine, and valine. Total amino acid reached 401.45 g·kg-1, and corresponded with the standard recommended by the Food and Agriculture Organization of theUnited Nations for amino acids, except sulfur-containing amino acids.