Research for the Environment

Determination of hydrogen threshold values during aromatics degradation under sulphate-reducing conditions

Microbial degradation of aromatic compounds, e.g. benzoate, phenol or BTEX-compounds (benzene, toluene, xylene, ethylbenzene) can be carried out by single organisms or by syntrophic consortia. In syntrophic consortia two or more microorganisms combine their metabolic capabilities to breakdown a substrate that could not be broken down by either one of them. In these communities interspecies hydrogen transfer often plays an important role. As energy yields during the degradation of aromatic substrates are often marginal, degradation is themodynamically feasible only when hydrogen concentrations are low. So far, hydrogen concentrations evolving in sulfate reducing communities in the course of fermentation have been determined, and found to be comparable among each other. However, it is not known how these hydrogen concentrations compare to such of single strains degrading aromatic substrates, and whether hydrogen concentrations could for instance be used as an indicator of aromatics degradation by single organisms/syntrophic consortia.
In this bachelor project different pure cultures and syntrophic consortia of aromatic degrading sulfate reducing bacteria will be grown. Growth parameters like substrate consumption and sulfide production will be monitored, and hydrogen concentrations will be determined.
Candidates should have a background in biology, biochemistry or related subjects and should be interested in the cultivation of microorganisms under anaerobic conditions, in physiological investigations as well as in using different analytical techniques.

Kontakt: Dr. Kathleen Schleinitz (
Dr. Carsten Vogt (
Helmholtz-Zentrum für Umweltforschung – UFZ
Dept. Umweltmikrobiologie bzw.
Dept. Isotopenbiogeochemie
Permoserstr. 15
04318 Leipzig
Tel. 0341 / 235-1378 (Schleinitz)
Betreuender Hochschullehrer: Prof. Dr. Hauke Harms


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