Circular economyeast: Saccharomyces cerevisiae as a sustainable source of glucans and its safety for skincare application

• Published in: International journal of biological macromolecules Vol. 265; no. Pt 2; p. 130933
• Main Authors: Sousa, Pedro, Tavares-Valente, Diana, Pereira, Carla F., Pinto-Ribeiro, Inês, Azevedo-Silva, João, Madureira, Raquel, Ramos, Óscar L., Pintado, Manuela, Fernandes, João, Amorim, Manuela
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2024
• Subjects: cell walls; circular economy; cytotoxicity; fermentation; genotoxicity; glucans; Glucans - chemistry; Glucans extraction; glucose; immunomodulators; ingredients; interleukin-6; interleukin-8; Polysaccharides - chemistry; Saccharomyces cerevisiae; Saccharomyces cerevisiae - chemistry; safety assessment; Skin safety; Spent yeast; Water; water solubility; yeasts; Glucans extraction; Spent yeast; Skin safety
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.130933

Glucans, a polysaccharide naturally present in the yeast cell wall that can be obtained from side streams generated during the fermentation process, have gained increasing attention for their potential as a skin ingredient. Therefore, this study focused on the extraction method to isolate and purify water-insoluble glucans from two different Saccharomyces cerevisiae strains: an engineered strain obtained from spent yeast in an industrial fermentation process and a wild strain produced through lab-scale fermentation. Two water-insoluble extracts with a high glucose content (> 90 %) were achieved and further subjected to a chemical modification using carboxymethylation to improve their water solubility. All the glucans' extracts, water-insoluble and carboxymethylated, were structurally and chemically characterized, showing almost no differences between both yeast-type strains. To ensure their safety for skin application, a broad safety assessment was undertaken, and no cytotoxic effect, immunomodulatory capacity (IL-6 and IL-8 regulation), genotoxicity, skin sensitization, and impact on the skin microbiota were observed. These findings highlight the potential of glucans derived from spent yeast as a sustainable and safe ingredient for cosmetic and skincare formulations, contributing to the sustainability and circular economy.