New dye-decolorizing peroxidases from Bacillus subtilis and Pseudomonas putida MET94: towards biotechnological applications

• Published in: Applied microbiology and biotechnology Vol. 98; no. 5; pp. 2053 - 2065
• Main Authors: Santos, Ana, Mendes, Sónia, Brissos, Vânia, Martins, Lígia O
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Analysis; Aromatic compounds; Azo dyes; Bacillus subtilis; Bacillus subtilis - enzymology; Bacteria; Biomedical and Life Sciences; Biotechnologically Relevant Enzymes and Proteins; Biotechnology; Cloning; Cloning, Molecular; Coloring Agents - metabolism; Decomposition (Chemistry); denaturation; Dyes; E coli; Effluents; enzyme activity; Enzyme Stability; Enzymes; Escherichia coli; Escherichia coli - genetics; Gene Expression; Genes; Genetic engineering; heme; Hydrogen-Ion Concentration; ions; Life Sciences; Lignin; Manganese; Microbial Genetics and Genomics; Microbiology; Microenvironments; Molecular Weight; Oxidation; Peroxidase; peroxidases; Peroxidases - chemistry; Peroxidases - genetics; Peroxidases - isolation & purification; Peroxidases - metabolism; phenolic compounds; Phenols; Physiological aspects; Properties; Protein Multimerization; Proteins; Pseudomonas putida; Pseudomonas putida - enzymology; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Redox potential; spectroscopy; Studies; Substrate Specificity; Temperature; Portugal; Phenols; Dye-decolorizing peroxidase; Dye decolorization
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-013-5041-4

This work provides spectroscopic, catalytic, and stability fingerprints of two new bacterial dye-decolorizing peroxidases (DyPs) from Bacillus subtilis (BsDyP) and Pseudomonas putida MET94 (PpDyP). DyPs are a family of microbial heme-containing peroxidases with wide substrate specificity, including high redox potential aromatic compounds such as synthetic dyes or phenolic and nonphenolic lignin units. The genes encoding BsDyP and PpDyP, belonging to subfamilies A and B, respectively, were cloned and heterologously expressed in Escherichia coli. The recombinant PpDyP is a 120-kDa homotetramer while BsDyP enzyme consists of a single 48-kDa monomer. The optimal pH of both enzymes is in the acidic range (pH 4–5). BsDyP has a bell-shape profile with optimum between 20 and 30 °C whereas PpDyP shows a peculiar flat and broad (10–30 °C) temperature profile. Anthraquinonic or azo dyes, phenolics, methoxylated aromatics, and also manganese and ferrous ions are substrates used by the enzymes. In general, PpDyP exhibits higher activities and accepts a wider scope of substrates than BsDyP; the spectroscopic data suggest distinct heme microenvironments in the two enzymes that might account for the distinctive catalytic behavior. However, the Bs enzyme with activity lasting for up to 53 h at 40 °C is more stable towards temperature or chemical denaturation than the PpDyP. The results of this work will guide future optimization of the biocatalytis towards their utilization in the fields of environmental or industrial biotechnology.