Effect of community structure on the kinetics of anaerobic degradation of aromatic compounds

Abstract

The kinetics of benzoate degradation by Syntrophus buswellii grown in coculture with Desulfovibrio strain G11 was determined. Benzoate was degraded to a threshold value where no futher benzoate degradation was detected even after long incubation times. The addition of sodium acetate, but not sodium chloride, was found to affect the threshold value with higher values observed at higher acetate concentrations. Syntrophus buswellii was isolated in pure culture with crotonate as the substrate. Also, an anaerobic, fermentative bacterium that metabolizes 3-chlorophenoxyacetate and phenoxyacetate to the corresponding phenol was isolated in pure culture. The synthesis of poly-3-hydroxyalkanoate (PHA) in Syntrophomonas wolfei was studied. The bacterium synthesized PHA directly from the {Beta}-oxidation intermediate during the initial stages of growth. Later, PHA was made by the condensation of two acetyl-CoA molecules. The genes for PHA synthesis in S. wolfei have been cloned into Escherichia coli.