Consolidation and cytotoxicity analysis of a purification strategy for biotechnological xylitol production using fixed bed column adsorption and nanofiltration membranes

Abstract

Agro-industrial waste is increasingly utilized in biotechnological processes to convert lignocellulosic materials into high-value products, such as xylitol. This polyol can be produced using biotechnological methods that mitigate environmental impacts, but it entails high purification costs. The article proposes a comparative study between two sequential strategies for purifying biotechnological xylitol. The first strategy involves membrane filtration followed by column adsorption. While the second strategy only covers column adsorption with twice the adsorbent bed. Additionally, the study includes a cytotoxicity evaluation of various purified xylitol fractions. Column adsorption was conducted at 70 °C with a flow rate of 1.2 mL min⁻¹ using activated carbon as the adsorbent. It proved to be efficient in separating colored compounds, proteins, and ethanol, with retention coefficients of 99.23 %, 84.0 %, and 96.71 %, respectively. The purification factor of xylitol/ethanol was 14.84. Nanofiltration was performed using a poly (piperazine amide) membrane at 40 °C and 30 bar, resulting in a protein retention of 43.55 % and a xylitol purity of 27.73 %. Finally, purified xylitol fractions underwent cytotoxicity analysis using the MTT assay, conducted in intestinal epithelial cells (Caco-2). One of the analyzed fractions did not induce toxicity, demonstrating that activated carbon column adsorption was the most effective strategy for purifying biotechnologically produced xylitol. These findings contribute to enhancing the viability of biotechnological xylitol production from sugarcane bagasse hemicellulosic hydrolysate.