SPP 1319:  Biological Transformations without Oxygen: From the Molecular to the Global Scale

• Subject Area: Medicine ; Biology ; Chemistry
• Term: from 2008 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 36065184

Hydrocarbons are an important fossil energy source and serve as widely used raw material for the chemical industry. On the other side, they comprise many toxic compounds, which are of environmental concern due to their persistence and relatively high water solubility. The biological formation, transformation and degradation of hydrocarbons play an important role in the global carbon cycle. In the absence of oxygen, the quantitatively important anaerobic metabolism of hydrocarbons comprises many so far unknown enzymatic processes. In particular, the initial reactions involved in activation of chemically inert C-H-bonds appear to follow unprecedented biochemical principles.
The objective of the interdisciplinary Priority Programme is to study the anoxic transformations of hydrocarbons in a greater scientific environment. Researchers in the field of ecophysiology, microbiology, biogeochemistry, biochemistry, chemistry and structural biology/biophysics are involved. The following major questions are being studied:
(1) What novel enzymatic principles are involved in the anaerobic transformation of hydrocarbons?
(2) Which role do these biological transformations indeed play in nature?
(3) Which ecological and geochemical parameters have an impact on hydrocarbon metabolising organisms/processes in nature? The studies are carried out with hydrocarbon model compounds with characteristic structural features such as chemically inert C-H and C-C bonds. The compounds studied comprise saturated and non-saturated alkanes, isoprenoids and aromatic hydrocarbons. Next to the initial activation reactions, further typical reactions in the metabolism of hydrocarbons will be studied such as benzene ring dearomatisation or the cleavage of cyclohexane rings. In addition, hydrocarbon analogues carrying chemically inert C-H bonds are studied.
The main objective is to obtain novel insights into the anoxic metabolic processes involved in the transformation of hydrocarbons and their in situ regulation. The following topics are part of the research programme:
(1) biochemical identification of novel or poorly understood enzymatic reactions including the isolation of enzymes their structural and regulatory characterisation,
(2) the elucidation of reactions mechanism by studying analogous chemical reactions,
(3) the quantitative determination of the impact of geochemical and biological parameters on the transformations of hydrocarbons and
(4) the identification and isolation of novel organisms with the capacity to anaerobically degrade methane, alkanes, aromatic hydrocarbons.

• DFG Programme: Priority Programmes
• International Connection: United Kingdom

Projects

• Acetone carboxylation as a model reaction for anaerobic activation of hydrocarbons (Applicant Schink, Bernhard )
• Anaerobic alkane and alkene metabolism in sulfate-reducing prokaryotes (Applicant Heider, Johann )
• Anaerobic bacterial metabolism of cholesterol (Applicant Boll, Matthias )
• Anoxic Enzymatic Conversion of Acetylene (Applicant Einsle, Oliver )
• BSS and beyond - functional markers to unravel the ecology of anaerobic hydrocarbon degraders in the environment (Applicant Lüders, Tillmann )
• Characterization of the biochemistry and physiology of hydrocarbon degradation pathways by stable isotope-based approaches (Applicant Richnow, Hans Hermann )
• Computational Investigation of Mechanisms of Enzymes Involved in the Anaerob Degradation of Hydrocarbons (Applicant Ullmann, Matthias )
• Elucidation of anaerobic benzene and alkylated aromatic compound degradation pathways and associated proteins by proteomic and metabolomic analyses (Applicant Seifert, Jana )
• Elucidation of reaction mechanisms in the anaerobic degradation of hydrocarbons (Applicants Buckel, Wolfgang ;  Golding, Bernhard )
• Enzymatic reactions involved in anaerobic naphthalene degradation (Applicant Meckenstock, Rainer Udo )
• Identification and characterization of benzene carboxylase, the key enzyme in anaerobic benzene degradation (Applicant Meckenstock, Rainer Udo )
• Mechanisms and microorganisms involved in degradation of BTEX and PAH under methanogenic conditions (Applicant Krüger, Martin )
• Mechanistic investigations on the pathway of n-alkane oxidation in anaerobic bacteria (Applicant Wilkes, Heinz )
• Microorganisms degrading cyclic and short-chain alkanes under anoxic conditions (Applicant Musat, Florin )
• Molecular ecology and biochemistry of cyclohexenoyl-CoA hydrolysing/forming enzymes (Applicant Boll, Matthias )
• Molecular ecology of sulphate-reducing bacteria involved in anaerobic degradation of hydrocarbons at marine gas and oil seeps (Applicant Knittel, Katrin )
• Multifrequency (9, 34 and 94 GHz) EPR investigations of paramagnetic intermediates in heterodisulfide reductase and related enzymes (Applicant Bennati, Marina )
• Natural anaerobic degradation of methane and petroleum in marine sediments: geochemical gradients, degradation succession and microbial zonation (Applicant Wallmann, Klaus )
• Novel multi-site enzymes in the transformation of aliphatic and aromatic hydrocarbons (Applicant Kroneck, Peter M. H. )
• Pathway diversity and stereochemistry of anaerobic degradation of alkyltoluenes/-benzoates (Applicants Rabus, Ralf ;  Wilkes, Heinz )
• Quantum chemical studies on the spectroscopic and reactive properties of short lived intermediates in selected anaerobic enzymes (Applicant Neese, Frank )
• Structural biochemistry of 4-hydroxyphenylacetate decarboxylase, benzylsuccinate synthase and respective activating-enzymes (Applicant Martins, Berta )
• Structure and reaction mechanism of benzylsuccinate synthase and its activating enzyme (Applicant Heider, Johann )
• The role of uncharacterized methyl-x:coenzyme M methyltransferases for activation of novel methylotrophic energy substrates in Methanosarcina acetivorans (Applicant Rother, Michael )
• Unusual enzyme complexes in anaerobic aromatic metabolism of Geobacter metallireducens (Applicant Boll, Matthias )
• X-ray structure analysis on key enzymes involved in the anaerobic degradation of hydrocarbons (Applicant Ermler, Ulrich )

• Spokesperson: Professor Dr. Matthias Boll
• Deputy: Professor Dr. Rainer Udo Meckenstock