High-yield production of aromatic peroxygenase by the agaric fungus Marasmius rotula
1 Department of Biology, Chemistry and Process Technology, Lausitz University of Applied Sciences, Großenhainer Straße 57, 01968 Senftenberg, Germany
2 Department of Environmental Biotechnology, Department of Bio- and Environmental Sciences, International Graduate School of Zittau, Markt 23, 02763 Zittau, Germany
3 Department of Soil Ecology, Helmholtz Centre for Environmental Research - UFZ Halle, Theodor-Lieser-Straße 4, 06120 Halle/Saale, Germany
4 JenaBios GmbH, Orlaweg 2, 07743 Jena, Germany
AMB Express 2011, 1:31 doi:10.1186/2191-0855-1-31Published: 11 October 2011
An extracellular peroxygenase from Marasmius rotula was produced in liquid culture, chromatographically purified and partially characterized. This is the third aromatic peroxygenase (APO) that has been characterized in detail and the first one that can be produced in high yields. The highest enzyme levels of about 41,000 U l-1 (corresponding to appr. 445 mg l-1 APO protein) exceeded the hitherto reported levels more than 40-fold and were detected in carbon- and nitrogen-rich complex media. The enzyme was purified by FPLC to apparent homogeneity (SDS-PAGE) with a molecular mass of 32 kDa (27 kDa after deglycosylation) and isoelectric points between 4.97 and 5.27. The UV-visible spectrum of the native enzyme showed a characteristic maximum (Soret band) at 418 nm that shifted after reduction with sodium dithionite and flushing with carbon monoxide to 443 nm. The pH optimum of the M. rotula enzyme was found to vary between pH 5 and 6 for most reactions studied. The apparent Km-values for 2,6-dimethoxyphenol, benzyl alcohol, veratryl alcohol, naphthalene and H2O2 were 0.133, 0.118, 0.279, 0.791 and 3.14 mM, respectively. M. rotula APO was found to be highly stable in a pH range from 5 to 10 as well as in the presence of organic solvents (50% vol/vol) such as methanol, acetonitrile and N,N-dimethylformamide. Unlike other APOs, the peroxygenase of M. rotula showed neither brominating nor chlorinating activities.