Büro für Altlastenerkundung und Umweltforschung

Dr. Rainer Haas

Stadtwaldstr. 45a, D-35037 Marburg, Tel.: 06421/93084, Fax: 06421/93073

email: haasr@gmx.net

Degradation of Chemical Warfare Agents by Manganese Peroxidase (MnP)

Dr. Katrin Scheibner¹, Dr. Rainer Haas², Dipl. Ing. Alfred Krippendorf³, Dr. Martin Hofrichter¹,

1: Friedrich Schiller University of Jena, Institute of Microbiology, Philosophenweg 12, D 07743 Jena

2: Office for Hazardous Waste Exploration, Stadtwaldstr. 45a, D 35037 Marburg

3: Hazard Control Ltd., Eugen Saenger Str. 52, D 29328 Fassberg

Enzymatic Combustion by Manganese Peroxidase (MnP)

Manganese peroxidase (MnP) is solely produced by certain basidiomycetous fungi colonizing lignocelluloses. The natural function of MnP is the degradation of the complex lignin polymer providing strength and rigidity to all higher plants. MnP oxidizes manganese(II) ions (Mn²⁺) into highly reactive manganese(III) ions (Mn³⁺).

Mn³⁺ is stabilized to high redox potentials via chelation with organic acids (i.e. malonate oxalate). Mn³⁺ chelates are the actual oxidizing agent of the MnP system acting as a low molecular weight redox mediator.

In addition to lignin, chelated Mn³⁺ oxidizes various aromatic and aliphatic compounds by abstracting hydrogen and/or an electron resulting in the formation of radicals which in turn, underly a huge number of spontaneous reactions (i.e. incorporation of oxigen, bond cleavages, decarboxylation).

As the only enzyme, so far known, MnP has the ability to mineralize organic substances including organopollutants, e.g. 2,4,6 trinitrotoluene (TNT), benzo(a)pyrene, pentachlorophenol (PCP) and halogenated humic acids directly to carbon dioxide (enzymalic combustion).

The MnP catalyzed enzymatic combustion of organic compounds is promoted by secondary mediators (i.e. organic thiols, unsaturated lipids). The MnP used in this investigation was isolated from Nematoloma frowardii b 19.

Degradation of Arsenical Chemical Warfare Agents (CWA)

Alkyl , chloroviny  and phenyl arsenic compounds were produced as chemical warfare agents during WW I and WW II. Some of this compounds are stable under environmental conditions. Residues of this CWA are still contaminating soil and water today. No biological method was known to destroy this arsenical CWA, because of their high toxicity.

We investigated the degradation of these arsenical CWA by the isolated MnP system. All investigated arsenical compounds were destroyed after treatment with MnP, no organic arsenical compounds were detected with GC/MS. The destruction rates are shown in table 1.

The destruction of arsenical CWA by manganese peroxidase could be a used to clean up arsenical CWA contaminated sites.

Table 1: Conversion of arsenic containing chemical warfare agents by manganese peroxidase

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