Anaerobic Aromatic Compound and Hydrocarbon Degradation
The aromatic ring belongs next to the glycosyl-ring to the most abundant organic chemical structures in the biosphere. Aromatic compounds are major constituents of proteins, lignin, flavonoids, tannins, crude oil and are widely used as solvents or starting compounds in industrial chemical synthesis. Hydrocarbons are also widely distributed in nature, even though they are mainly known as dominant constituents of crude oil. Aromaticity and apolar nature of hydrocarbons determine the high chemical stability of these compounds and in a reverse conclusion necessitate special reactions for their biodegradation.
Anoxic conditions prevail in many natural environments, such as marine sediments, oil reservoirs and ground water aquifers. Anaerobic degradation of aromatic compounds and hydrocarbons requires reactions which are fundamentally different from the oxygenase-catalysed reaction employed under oxic conditions.
Several lines of research are pursued at present:
- aryl- and alkylsuccinate formation as widespread initial reaction in anaerobic hydrocarbon degradation among diverse denitrifying and sulfate-reducing bacteria;
- microbiology of anaerobic crude oil biodegradation;
- novel reactions involved in anaerobic p-alkylbenzoate degradation;
- proteogenomic reconstruction of the catabolic network and its superimposed regulatory circuits in denitrifying, aromatic compound-degrading "A. aromaticum" strain EbN1.
In addition to the basic scientific interest in the novel reactions/pathways involved in anaerobic aromatic compound and hydrocarbon degradation, also applied interest exists: (i) better understanding and control of bioremediation efforts at contaminated sites (e.g. groundwater aquifers or harbour sediments), (ii) elucidation of the microbial key processes driving undesired biodegradation of oil reservoirs, and (iii) inspiration of biomimetic design of novel catalysts for industrial chemical synthesis.
GfZ Potsdam (H. Wilkes), MPI Bremen (F. Widdel), University Marburg (H. Heider)