BioProject

Insight into the mechanisms for the anaerobic metabolism of aromatic compounds by the hyperthermophilic archaeon Ferroglobus placidus is expected to improve understanding of the degradation of aromatics in hot (> 80 °C) environments and to identify enzymes that might have biotechnological applications. More...

Insight into the mechanisms for the anaerobic metabolism of aromatic compounds by the hyperthermophilic archaeon Ferroglobus placidus is expected to improve understanding of the degradation of aromatics in hot (> 80 °C) environments and to identify enzymes that might have biotechnological applications. Analysis of the F. placidus genome revealed genes predicted to encode enzymes homologous to those previously identified as playing a role in benzoate and phenol metabolism in mesophilic bacteria. Surprisingly, F. placidus lacks genes for an ATP-independent class II benzoyl-CoA reductase found in all strictly anaerobic bacteria, but instead has two sets of genes for ATP-consuming class I benzoyl-CoA reductases, similar to those found in facultative bacteria. The lower portion of the benzoate degradation pathway appears to be more similar to that found in the phototroph Rhodopseudomonas palustris, than the pathway reported for all heterotrophic anaerobic benzoate degraders. Many of the genes predicted to be involved in benzoate metabolism were found in one of two gene clusters. Genes for a phenol carboxylation proceeding through a phenylphosphate intermediate and for conversion of p-hydroxybenzoate to benzoyl-CoA were identified in a single gene cluster. Analysis of transcript abundance with a whole-genome microarray and quantitative PCR demonstrated that most of the genes predicted to be involved in benzoate or phenol metabolism had higher transcript abundance during growth on those substrates versus growth on acetate. These results suggest that the general strategies for benzoate and phenol metabolism may be highly conserved between microorganisms living in moderate and hot environments, and that anaerobic metabolism of aromatic compounds might be analyzed in a wide range of environments with similar molecular targets. Overall design: A four chip study using total RNA recovered from two separate cultures of Ferroglobus placidus DSM 10642 grown with 1 mM sodium benzoate (experimental condition) and two separate cultures of Ferroglobus placidus DSM 10642 grown on 10 mM acetate (control condition). Each chip measures the expression level of 2613 genes from Ferroglobus placidus DSM 10642 with nine 45-60-mer probe pairs (PM/MM) per gene, with three-fold technical redundancy. Less...