Production of manno-oligosaccharides from locust bean gum using immobilized Penicillium occitanis mannanase

Mannanase was immobilized on chitin with glutaraldehyde by cross-linking reaction. The immobilization conditions and the characterization of immobilized enzyme were carried out. The immobilization yield and the mannanase activity recovery were 94.81% and 72.17%, respectively. The optimal mannanase activity shifted to lower pH after immobilization. However, the optimum temperature remained unchanged at 70 °C. The immobilized enzyme exhibited better thermal and pH stability than the free one. It also exhibited a high storage stability and retained 70% of its initial activity after 120 days. The main hydrolysis products yielded from locust bean gum were mannotriose and mannotetraose. The resulting manno-oligosaccharides could be used as a special nutrient for lactic bacteria.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Immobilized mannanase on chitin crosslinked by glutaraldehyde. ► Immobilized enzyme exhibited better thermal and pH stability than the free one. ► Immobilized mannansase is suitable for practical manno-oligosaccharide production.