Degradation of Phenol via Phenylphosphate and Carboxylation to 4-Hydroxybenzoate by a Newly Isolated Strain of the Sulfate-Reducing Bacterium Desulfobacterium anilini

• Published in: Applied and Environmental Microbiology Vol. 75; no. 13; pp. 4248 - 4253
• Main Authors: Ahn, Young-Beom, Chae, Jong-Chan, Zylstra, Gerben J, Häggblom, Max M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.07.2009; American Society for Microbiology (ASM)
• Subjects: Acetates - metabolism; Acetic acid; Anaerobiosis; Bacteria; Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; Bacterial Typing Techniques; Bacteriology; Biodegradation; Biological and medical sciences; Cluster Analysis; Deltaproteobacteria - metabolism; Deoxyribonucleic acid; DNA; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Profiling; Genes; Microbiology; Molecular Sequence Data; Organophosphates - metabolism; Oxidation-Reduction; Parabens - metabolism; Phenol - metabolism; Phylogeny; Pyruvic Acid - metabolism; Ribonucleic acid; RNA; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Sulfates - metabolism; Sulfur; Degradation; Carboxylation; Phenols; Sulfate-reducing bacteria; Phenol
• DOI: 10.1128/AEM.00203-09
• ISSN: 0099-2240

A sulfate-reducing phenol-degrading bacterium, strain AK1, was isolated from a 2-bromophenol-utilizing sulfidogenic estuarine sediment enrichment culture. On the basis of phylogenetic analysis of the 16S rRNA gene and DNA homology, strain AK1 is most closely related to Desulfobacterium anilini strain Ani1 (= DSM 4660T). In addition to phenol, this organism degrades a variety of other aromatic compounds, including benzoate, 2-hydroxybenzoate, 4-hydroxybenzoate, 4-hydroxyphenylacetate, 2-aminobenzoate, 2-fluorophenol, and 2-fluorobenzoate, but it does not degrade aniline, 3-hydroxybenzoate, 4-cyanophenol, 2,4-dihydroxybenzoate, monohalogenated phenols, or monohalogenated benzoates. Growth with sulfate as an electron acceptor occurred with acetate and pyruvate but not with citrate, propionate, butyrate, lactate, glucose, or succinate. Strain AK1 is able to use sulfate, sulfite, and thiosulfate as electron acceptors. A putative phenylphosphate synthase gene responsible for anaerobic phenol degradation was identified in strain AK1. In phenol-grown cultures inducible expression of the ppsA gene was verified by reverse transcriptase PCR, and 4-hydroxybenzoate was detected as an intermediate. These results suggest that the pathway for anaerobic degradation of phenol in D. anilini strain AK1 proceeds via phosphorylation of phenol to phenylphosphate, followed by carboxylation to 4-hydroxybenzoate. The details concerning such reaction pathways in sulfidogenic bacteria have not been characterized previously.