Project description:The degradation of aromatic compounds comprises an important step in the removal of pollutants and re-utilization of plastics and other non-biological polymers. Here we set out to study Pseudomonas sp. strain phDV1, a gram-negative bacterium that was selected for its ability to degrade aromatic compounds. In order to understand how the aromatic compounds and their degradation products are reintroduced in the metabolism of the bacteria and the systematic/metabolic response of the bacterium to the new carbon source, the proteome of this strain was analysed in the presence of succinate, phenol and o-, m-, p-cresol as sole carbon source. We then applied label-free quantitative proteomics to monitor overall proteome remodeling during metabolic adaptation to different carbon sources. As a reference proteome, we grew the bacteria in succinate and then compared the respective proteomes of bacteria grown on phenol and different cresols. In total, we identified 2295 proteins; 1908 proteins were used for quantification between different growth conditions. We found that 70, 100, 150 and 155 proteins were significantly differentially expressed in cells were grown in phenol, o-, m- and p-cresol-containing medium, respectively. The carbon source affected the synthesis of enzymes related to aromatic compound degradation, and in particular, the enzyme involved in the meta-pathway of monocyclic aromatic compounds degradation. In addition, proteins involved in the production of polyhydroxyalkanoate (PHA), an attractive biomaterial, showed higher expression levels in the presence of monocyclic aromatic compounds.Our results provide for the first time comprehensive information on the proteome response of this strain to monocyclic aromatic compounds.
Project description: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.
Project description:Novosphingobium resinovorum strain SA1 is one of few strains capable of degrading sulfanilic acid which is a widely used representative of sulfonated aromatic compounds. In order to identify the elements involved in the biodegradation process and to understand the metabolic responces of the cells exposed to this aromatic compound, we performed a whole transcriptome analysis of cells grown on sulfanilic acid and glucose. Additionally, for distinguish the potential stress/starvation effects of the xenobiotic we compared the transcript profiles of samples taken from both the exponential and stationary growth phases.
Project description: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. 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.
Project description:A bacterial strain identified as Cupriavidus basilensis uses aromatic compounds as carbon and energy sources and has a high capability to transform the structurally related and hormonally active substance bisphenol A (BPA). Biphenyl-grown and phenol-grown cells converted BPA to five products within 24 h of incubation representing four different transformation pathways: (a) ring hydroxylation, (b) ring fission, (c) transamination and acetylation, and (d) dimerization. Products of the ring fission pathway were non-toxic and all five products exhibited a significantly reduced estrogenic activity compared to BPA. Cell cultivation in nutrient broth resulted in lower product quantities and dimerization was not proved. Thus the question arose whether enzymes of the biphenyl or phenol degradation pathway are involved in the transformation of BPA. Proteomic analyses revealed the constitutive expression of biphenyl degrading enzymes and indicated that the 2,3 dihydroxybiphenyl-1,2-dioxygenase might catalyse the meta-cleavage of the aromatic ring of BPA while enzymes of other pathways seemed to be involved in ring hydroxylation.