Exploring the biotechnological potential of Candida boidinii XM02G: High xylitol production efficiency and high tolerance to inhibitory compounds.

The yeast C. boidinii exhibits high tolerance to extreme environments. This characteristic makes it a microorganism with significant biotechnological potential, particularly for xylitol production. However, this potential remains underexplored. Xylitol is an alternative to sucrose, offering equivalent sweetness, lower caloric content, and insulin-independent metabolism, making it suitable for diabetic individuals and applicable in dental, pharmaceutical, and food industries. Given its relevance, this study aimed to investigate xylitol production by C. boidinii XM02G and its resistance to lignin-derived inhibitory compounds. C. boidinii XM02G was isolated from a cocoa cultivation area and cultivated in synthetic medium for xylitol production. The yeast's resistance was tested against phenolic inhibitors: benzoic acid, syringic acid, p-hydroxybenzoic acid, and ferulic acid. A yield of 0.80 g g-1 and an efficiency of 87.2% were obtained under initial conditions of pH 5 and xylose concentration of 40 g L-1. The yeast showed tolerance to most tested inhibitors, even at concentrations higher than those found in lignocellulosic biomass hydrolysates, producing 16.8 g L-1 of xylitol in the presence of p-hydroxybenzoic acid. Only benzoic acid at concentrations of 0.5 and 1.0 g L-1 completely inhibited cell growth and xylitol production. These results highlight the biotechnological potential of C. boidinii XM02G, suggesting it as a promising microorganism due to its notable inhibitor tolerance-an essential trait for biomass-based biorefinery applications.