ARPHA Conference Abstracts : Conference Abstract
Conference Abstract
Chemo-organo-autotrophic degradation of aromatic hydrocarbons indicates a new type of bacterial metabolism
expand article infoRainer U. Meckenstock, Isabelle Heker, Christian Seitz§, Lisa Voskuhl, Wolfgang Eisenreich§
‡ University of Duisburg-Essen, Essen, Germany
§ Technical University of Munich, Munich, Germany
Open Access


The sulfate-reducing culture N47 can grow with naphthalene and has a complete tricarboxylic acid cycle (TCA) and Wood-Ljungdahl pathway (WLP) while other organisms have only either of them. Here, we wanted to elucidate why N47 has two complete pathways potentially able to oxidize acetyl-CoA. Enzyme activities were measured in cell extracts indicating a fully functional rTCA and WLP. To elucidate the carbon flux through the pathways, cells were grown with 13C-labeled naphthalene or 13C-bicarbonate buffer. Amino acids and fatty acids were analysed for position specific 13C-incorporation with GC-MS, which indicated that in catabolism, acetyl-CoA from naphthalene was fully oxidized to CO2 via the WLP. Acetyl-CoA for anabolism of amino acids, fatty acids and carbohydrates was surprisingly not coming from the substrate naphthalene but is generated de novo by CO2-fixation, making N47 a chemoorganoauto-trophic microorganism. This indicates that chemoorganoauto-trophy can also occur with complex substrates but probably requires a complete WLP and rTCA in anaerobic microorganisms.


Central metabolism, chemo-organo-auto trophy, TCA-cycle, Wood-Ljungdahl pathway, anaerobic hydrocarbon degradation, sulfate-reduction

Presenting author

Rainer U. Meckenstock

Presented at

ISEB-ISSM 2023 joint meeting

Hosting institution

University of Duisburg-Essen, Environmental Microbiology and Biotechnology

Conflicts of interest

The authors have declared that no competing interests exist.
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