Single-cell Protein and Xylitol Production by a Novel Yeast Strain Candida intermedia FL023 from Lignocellulosic Hydrolysates and Xylose

Abstract

Yeasts are good candidates to utilize the hydrolysates of lignocellulose, the most abundant bioresource, for bioproducts. This study aimed to evaluate the efficiencies of single-cell protein (SCP) and xylitol production by a novel yeast strain, Candida intermedia FL023, from lignocellulosic hydrolysates and xylose. This strain efficiently assimilated hexose, pentose, and cellubiose for cell mass production with the crude protein content of 484.2 g kg−1 dry cell mass. SCP was produced by strain FL023 using corncob hydrolysate and urea as the carbon and nitrogen sources with the dry cell mass productivity 0.86 g L−1 h−1 and the yield of 0.40 g g−1 sugar. SCP was also produced using NaOH-pretreated Miscanthus sinensis straw and corn steep liquor as the carbon and nitrogen sources through simultaneous saccharification and fermentation with the dry cell productivity of 0.23 g L−1 h−1 and yield of 0.17 g g−1 straw. C. intermedia FL023 was tolerant to 0.5 g L−1 furfural, acetic acid, and syringaldehyde in xylitol fermentation and produced 45.7 g L−1 xylitol from xylose with the productivity of 0.38 g L−1 h−1 and the yield of 0.57 g g−1 xylose. This study provides feasible methods for feed and food additive production from the abundant lignocellulosic bioresources.