Zonfrillo Beatrice, Bellumori Maria, Truzzi Eleonora, Khatib Mohamad, Faraoni Paola, Bertelli Davide, Ranaldi Francesco, Mulinacci Nadia
Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, via Ugo Schiff 6, Sesto Fiorentino, Italy.
Department of Life Science, University of Modena-Reggio Emilia, Via Campi 103, Modena, Italy.
Food Chem. 2025 Nov 15;492(Pt 3):145618. doi: 10.1016/j.foodchem.2025.145618. Epub 2025 Jul 21.
Ulvan oligosaccharides, which exhibit greater solubility than high molecular weight ulvan, hold significant potential for the valorization of Ulva biomass. They have been shown to promote the growth of probiotic bacteria in fermentation models and have demonstrated protective and anti-inflammatory effects in animal models. The enzymatic hydrolysis of ulvan using the commercial ulvan lyase PLSV_3875 bypasses the challenge posed by the resistance of ulvanobiuronic acids to conventional acidic hydrolysis. This study aimed to develop a rapid, scalable, and efficient method for a complete ulvan hydrolysis under reduced salt concentrations, yielding oligosaccharides suitable for biological applications. The enzyme's robustness and kinetic parameters were evaluated. Enzyme activity was assessed at pH 6-10.5 with 0-100 mM Tris-HCl, carbonate or phosphate buffer, and 0-200 mM NaCl/KCl. Optimal conditions were identified as 3 mg/mL ulvan, 25 mM KCl, and 100 mM phosphate buffer at pH 7.5. The resulting oligosaccharides were characterized using 2D-NMR and UHPLC-MS/MS.
与高分子量的岩藻聚糖相比，岩藻寡糖具有更高的溶解度，在浒苔生物质的增值利用方面具有巨大潜力。研究表明，它们能促进发酵模型中益生菌的生长，并在动物模型中表现出保护和抗炎作用。使用商业岩藻聚糖裂解酶PLSV_3875对岩藻聚糖进行酶促水解，绕过了岩藻双糖醛酸对传统酸性水解的抗性所带来的挑战。本研究旨在开发一种快速、可扩展且高效的方法，在低盐浓度下实现岩藻聚糖的完全水解，得到适用于生物应用的寡糖。对该酶的稳定性和动力学参数进行了评估。在pH 6 - 10.5条件下，使用0 - 100 mM的Tris - HCl、碳酸盐或磷酸盐缓冲液以及0 - 200 mM的NaCl/KCl评估酶活性。确定最佳条件为3 mg/mL岩藻聚糖、25 mM KCl和pH 7.5的100 mM磷酸盐缓冲液。使用二维核磁共振和超高效液相色谱 - 串联质谱对所得寡糖进行了表征。
