WOLMAN Federico Javier
congresos y reuniones científicas
Immobilization and purification of soybean seed hull proteins of biotechnological interest identified by shotgun proteomic analysis
LAUTARO FIDEL BRACCO; FEDERICO JAVIER WOLMAN; MARÍA VICTORIA MIRANDA; OSVALDO CASCONE
Congreso; 18th European Congress on Biotechnology; 2018
European Federation of Biotechnology (EFB)
Soybean crops have had a huge development. Soybean consumption is led by oil and flour, for which the hull must be removed. However, hull contains valuable proteins that can be extracted prior to pellet it for animal food. The aim of this work was the proteomic characterization of soybean seed hull aqueous extract as a way to identify candidate proteins for downstream processing, thus allowing the revaluation of this by-product of soybean manufacture. A hull extract was concentrated by ultrafiltration and subjected to analysis by nano-HPLC-ESI-Orbitrap. A total of 149 proteins were identified, among them 60 with potential biotechnological application, 15 in high abundance including peroxidase, urease and glycinin. These proteins were immobilized on chitosan mini-spheres. Peroxidase immobilization yield was over 90% when mini-spheres were derivatized with the triazine dye Reactive Blue 4, selected after a screening with 19 dyes. For urease and glycinin, mini-spheres were chemically modified to obtain thiosulfonate derivatives, thus allowing the immobilization of urease (95% yield) and the purification of glycinin by elution with β-mercaptoethanol (70% yield). For immobilized urease, the pH of maximal activity shifted from 7 to 4-5, allowing its utilization in acidic media, i.e. decrease of urea concentration in wine. Thermal, operational and storage stability of the immobilized proteins were improved, as compared with the free enzymes. Immobilized peroxidase and urease were applied to solve real problems: degradation of phenols in wastewater and dosage of serum urea, respectively, along various cycles with no significant decrease in enzyme activity.