Format

Send to

Choose Destination
See comment in PubMed Commons below
Biosci Biotechnol Biochem. 2013;77(1):189-93. Epub 2013 Jan 7.

Identification and characterization of cellobiose 2-epimerases from various aerobes.

Author information

  • 1Nihon Shokuhin Kako Co., Ltd., Fuji, Shizuoka, Japan

Abstract

Cellobiose 2-epimerase (CE), found mainly in anaerobes, reversibly converts D-glucose residues at the reducing end of β-1,4-linked oligosaccharides to D-mannose residues. In this study, we characterized CE-like proteins from various aerobes (Flavobacterium johnsoniae NBRC 14942, Pedobacter heparinus NBRC 12017, Dyadobacter fermentans ATCC 700827, Herpetosiphon aurantiacus ATCC 23779, Saccharophagus degradans ATCC 43961, Spirosoma linguale ATCC 33905, and Teredinibacter turnerae ATCC 39867), because aerobes, more easily cultured on a large scale than anaerobes, are applicable in industrial processes. The recombinant CE-like proteins produced in Escherichia coli catalyzed epimerization at the C2 position of cellobiose, lactose, epilactose, and β-1,4-mannobiose, whereas N-acetyl-D-glucosamine, N-acetyl-D-mannosamine, D-glucose, and D-mannose were inert as substrates. All the CEs, except for P. heparinus CE, the optimum pH of which was 6.3, showed highest activity at weakly alkaline pH. CEs from D. fermentans, H. aurantiacus, and S. linguale showed higher optimum temperatures and thermostability than the other enzymes analyzed. The enzymes from D. fermentans, S. linguale, and T. turnerae showed significantly high k(cat) and K(m) values towards cellobiose and lactose. Especially, T. turnerae CE showed a very high k(cat) value towards lactose, an attractive property for the industrial production of epilactose, which is carried out at high substrate concentrations.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Taylor & Francis Icon for J-STAGE, Japan Science and Technology Information Aggregator, Electronic
    Loading ...
    Write to the Help Desk