Isolation of xylose-assimilating yeasts and optimization of xylitol production by a new Meyerozyma guilliermondii strain

• Published in: International microbiology Vol. 23; no. 2; pp. 325 - 334
• Main Authors: da Silveira, Fernando Augusto, Fernandes, Tatiana Alves Rigamonte, Bragança, Caio Roberto Soares, Balbino, Thércia Rocha, Diniz, Raphael Hermano Santos, Passos, Flávia Maria Lopes, da Silveira, Wendel Batista
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-05-2020; Spanish Society for Microbiology
• Subjects: Acetic acid; Aerobic conditions; Agitation; Applied Microbiology; Arabinose; Biomass; Biomedical and Life Sciences; Biorefineries; Carbon sources; Cellobiose; Eukaryotic Microbiology; Furfural; Growth conditions; Hydrolysates; Hypoxia; Life Sciences; Lignocellulose; Medical Microbiology; Meyerozyma guilliermondii; Microbial Ecology; Microbiology; Optimization; Original Article; Raffinose; Refining; Response surface methodology; Rhamnose; Statistical analysis; Sugar; Xylitol; Xylose; Yeast; Yeasts; Bio-based products; Biorefinery; Response surface methodology; Fermentation; Lignocellulosic biomass; Physiological characterization
• ISSN: 1139-6709; 1618-1905
• DOI: 10.1007/s10123-019-00105-0

Production of xylitol from lignocellulosic biomass is of interest to modern biorefineries, because this biomass should be processed into a spectrum of chemicals (bio-based products) and not only energy. The isolation of new yeast strains capable of efficiently converting xylose into xylitol and withstanding inhibitors released from biomass hydrolysis can contribute to making its production feasible in biorefineries. Forty-three out of 128 yeast strains isolated from the gut of Passalidae beetles were capable of assimilating xylose as the sole carbon source.
Meyerozyma guilliermondii
UFV-1 was selected due to its ability to grow and ferment D-xylose in a synthetic medium. This yeast assimilated the broad range of sugars present in lignocellulosic biomass hydrolysates, such as xylose, raffinose, cellobiose, rhamnose, arabinose, and glucose. Its optimum growth conditions were pH 8.0 and a temperature of 30 °C. In concentrations of 0.07 mol/L acetic acid, 0.05 mol/L 5-hydroximethylfurfural, and 0.04 mol/L furfural,
M. guilliermondii
UFV-1 did not grow. Maximum xylitol production in aerobiosis and hypoxia were 51.88 and 27.73 g/L, respectively. Under aerobic condition, xylose concentration and agitation rate were the factors which were statistically significant, while only the agitation rate was significant in hypoxia. We fitted a response surface (RS) that estimated the best agitation rate (113.33 rpm) and xylose concentration (90 g/L) for maximum xylitol production in aerobiosis. Therefore,
M. guilliermondii
UFV-1 displays potential for being used for xylitol production in biorefineries.