Exoproduction and Molecular Characterization of Peroxidase from Ensifer adhaerens

Featured Application This paper determined the culture conditions for optimal peroxidase production by Ensifer adhaerens NWODO-2, which are necessary for large-scale production. Moreover, utilization of agricultural residues as cheap renewable substrates by the bacteria would be a cost-effective means of peroxidase production. Abstract The increased industrial application potentials of peroxidase have led to high market demand, which has outweighed the commercially available peroxidases. Hence, the need for alternative and efficient peroxidase-producers is imperative. This study reported the process parameters for enhanced exoperoxidase production by Ensifer adhaerens NWODO-2 (accession number: KX640918) for the first time, and characterized the enzyme using molecular methods. Peroxidase production by the bacteria was optimal at 48 h, with specific productivity of 12.76 U mg(-1) at pH 7, 30 degrees C and 100 rpm in an alkali lignin fermentation medium supplemented with guaiacol as the most effective inducer and ammonium sulphate as the best inorganic nitrogen source. Upon assessment of some agricultural residues as sources of carbon for the enzyme production, sawdust gave the highest peroxidase productivity (37.50 U mg(-1)) under solid-state fermentation. A search of the polymerase chain reaction (PCR)-amplified peroxidase gene in UniProtKB using blastx showed 70.5% similarity to an uncharacterized protein in Ensifer adhaerens but phylogenetic analysis suggests that the gene may encode a catalase-peroxidase with an estimated molecular weight of approximately 31 kDa and isoelectric point of about 11. The nucleotide sequence of the detected gene was deposited in the GenBank under the accession number MF374336. In conclusion, the ability of the strain to utilize lignocellulosic materials for peroxidase production augurs well for biotechnological application as this would greatly reduce cost, which is a major challenge in industrial enzyme production.