de Arruda Gabriel Leda, Raymundo Maria Teresa F R, de Carvalho Layde Teixeira, da Silva Silvio S, Santos Júlio C
Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, Brazil.
World J Microbiol Biotechnol. 2025 Jul 28;41(8):289. doi: 10.1007/s11274-025-04497-2.
The complete use of all fractions of agro-industrial by-products is essential to promote sustainability and consolidated bioprocesses in biorefineries. Among the biomass fractions, hemicellulose is still underutilized and could be used to produce high value bioproducts, as fungal biopigments, emerging biomolecules with potential applications in different industrial sectors. Besides raw material, cultivation strategies such as the use of immobilized cells can be interesting for industrial applications, presenting advantages by favoring downstream steps and reuse of cells in repeated or continuous bioprocesses. In this study, the production of biopigments by Monascus ruber immobilized in polyurethane foam was evaluated as a strategy to valorize a xylose-rich sugarcane bagasse hemicellulosic hydrolysate. An experimental design was carried out and showed the optimum xylose/glucose ratio obtained was similar to the values usually found in sugarcane bagasse hemicellulosic hydrolysates. Then, the kinetic profile of the in situ immobilization of the fungus (simultaneous cell growth and adsorption) in polyurethane indicated an inoculum preparation time of 8 days of growth/immobilization before the process conducted in hydrolysate-based medium. The use of immobilized cells resulted in the production of biopigments with maximum values of 13.1 AU, 11.87 AU, and 11.32 AU of yellow, orange and red biopigments, respectively, in medium based on detoxified hydrolysate. The obtained results can contribute to the valorization of agro-industrial by-products as an alternative source of substrates, as well as to future research to explore the potential of immobilizing filamentous fungi in bioprocesses, such as the reuse of cells and continuous systems for production of biopigments.
充分利用农业工业副产品的所有组分对于促进生物炼制中的可持续性和整合生物过程至关重要。在生物质组分中，半纤维素仍未得到充分利用，可用于生产高价值生物产品，如真菌生物色素，这是一类在不同工业领域具有潜在应用价值的新兴生物分子。除了原材料外，固定化细胞等培养策略对于工业应用可能很有意义，通过有利于下游步骤以及在重复或连续生物过程中细胞的再利用而具有优势。在本研究中，评估了固定在聚氨酯泡沫中的红曲霉菌生产生物色素的情况，以此作为一种策略来提高富含木糖的甘蔗渣半纤维素水解产物的价值。进行了一项实验设计，结果表明所获得的最佳木糖/葡萄糖比例与甘蔗渣半纤维素水解产物中通常发现的值相似。然后，真菌在聚氨酯中原位固定（细胞生长和吸附同时进行）的动力学曲线表明，在基于水解产物的培养基中进行该过程之前，接种物制备需要8天的生长/固定时间。使用固定化细胞在基于解毒水解产物的培养基中分别产生了黄色、橙色和红色生物色素，其最大值分别为13.1 AU、11.87 AU和11.32 AU。所获得的结果有助于将农业工业副产品作为替代底物来源进行增值，以及为未来探索在生物过程中固定丝状真菌的潜力的研究做出贡献，例如细胞的再利用和生物色素生产的连续系统。
