Aqueous solutions of deep eutectic systems as reaction media for the saccharification and fermentation of hardwood xylan into xylitol

• Autor(a) principal: Romaní, Aloia
• Data de Publicação: 2020
• Outros Autores: Morais, Eduarda S., Soares, Pedro O., Freire, Mara G., Freire, Carmen S. R., Silvestre, Armando J. D., Domingues, Lucília
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/28586
• topic: Xylitol; Cholinium chloride; Urea; Xylan; Simultaneous saccharification and fermentation

The aim of this study was to evaluate the effect of aqueous solutions of deep eutectic solvent, Cholinium Chloride:Urea ([Ch]Cl:U) at50wt%and20 wt%,using differentmolar ratios(1:1, 2:1and 1:2)onthe enzymatic hydrolysis ofxylanforxyloseproduction anditssubsequent bioconversion into xylitolusing arecombinant yeast strain. The lowest xylan conversion into xylose (45%) was obtained using 1:2 [Ch]Cl:U molar ratio. On the other hand, the 1:1 [Ch]Cl:U molar ratio, at 20 wt% in water, improved this conversion, achieving the highest xylose yield (81.4%). The xylitol production was then optimized with [Ch]Cl:U (1:1) at 20 wt% by simultaneous saccharification and fermentation process, attaining 23.67 g/L, corresponding to 66.04% of xylitol yield. This study reveals the possibility of using xylan solubilized in DES aqueous solutions directly for xylitol production, thus assembling a one-step process.