Identification and characterization of a novel bacterial pyranose 2-oxidase from the lignocellulolytic bacterium Pantoea ananatis Sd-1.

OBJECTIVE: To identify and characterize a novel bacterial pyranose 2-oxidase (P2Ox) and investigate its potential use in lignin degradation applications.

RESULTS: A new bacterial P2Ox (PaP2Ox) enzyme was identified in the lignocellulolytic bacterium Pantoea ananatis Sd-1. The PaP2Ox open reading frame was cloned, and the encoded protein was heterologously expressed in an Escherichia coli expression system. Unlike another reported bacterial P2Ox enzyme, the purified PaP2Ox exhibits a homotetrameric spatial conformation that is similar to fungal P2Oxs, with each subunit having a molecular mass of 65 kDa. The recombinant PaP2Ox exhibits maximum activity at 50 °C and pH 6.5 with D-glucose as its preferred substrate. In addition, this enzyme was shown to work in combination with bacterial laccase in lignin degradation.

CONCLUSIONS: The bacterial enzyme PaP2Ox has potential use in ligninolytic systems and shows promising value in industrial biotechnological applications.