Tyramine-modified pectins via periodate oxidation for soybean hull peroxidase induced hydrogel formation and immobilization

• Published in: Applied microbiology and biotechnology 2017-03, Vol.101 (6), p.2281-2290
• Main Authors: Prokopijevic, Milos, Prodanovic, Olivera, Spasojevic, Dragica, Kovacevic, Gordana, Polovic, Natalija, Radotic, Ksenija, Prodanovic, Radivoje
• Format: Article
• Language: English
• Subjects: Amination; Batch reactors; Biomedical and Life Sciences; Biomedical materials; Biotechnological Products and Process Engineering; Biotechnology; Borohydrides - chemistry; Cell adhesion & migration; Drug delivery systems; Emulsion polymerization; Enzymes; Enzymes, Immobilized - chemistry; Equipment Reuse; Glycine max - chemistry; Glycine max - enzymology; Hydrogels; Hydrogels - chemistry; Hydrogen peroxide; Hydrogen Peroxide - chemistry; Hydrogen-Ion Concentration; Kinetics; Life Sciences; Microbial Genetics and Genomics; Microbiology; Oxidation; Oxidation-Reduction; Oxidation-reduction reactions; Pectin; Pectins - chemistry; Periodic Acid - chemistry; Peroxidase; Peroxidase - chemistry; Peroxides; Phenols; Plant Proteins - chemistry; Polymerization; Polymers; Sodium; Soybeans; Tissue engineering; Tyramine - chemistry; Waste Products; Wound healing
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-016-8002-x

Pectin was modified by oxidation with sodium periodate at molar ratios of 2.5, 5, 10, 15 and 20 mol% and reductive amination with tyramine and sodium cyanoborohydride afterwards. Concentration of tyramine groups within modified pectin ranged from 54.5 to 538 μmol/g of dry pectin while concentration of ionizable groups ranged from 3.0 to 4.0 mmol/g of dry polymer compared to 1.5 mmol/g before modification due to the introduction of amino group. All tyramine-pectins showed exceptional gelling properties and could form hydrogel both by cross-linking of carboxyl groups with calcium or by cross-linking phenol groups with peroxidase in the presence of hydrogen peroxide. These hydrogels were tested as carriers for soybean hull peroxidase (SHP) immobilization within microbeads formed in an emulsion based enzymatic polymerization reaction. SHP immobilized within tyramine-pectin microbeads had an increased thermal and organic solvent stability compared to the soluble enzyme. Immobilized SHP was more active in acidic pH region and had slightly decreased K m value of 2.61 mM compared to the soluble enzyme. After 7 cycles of repeated use in batch reactor for pyrogallol oxidation microbeads, immobilized SHP retained half of the initial activity.