Polycyclic aromatic compounds (PAHs) are toxic compounds that are released in the environment as a consequence of industrial activities. The restoration of PAH-polluted sites considers the use of bacteria capable of degrading aromatic compounds to carbon dioxide and water. Here we characterize a new Xanthobacteraceae strain, Starkeya sp.
View Article and Find Full Text PDFThe nitrate-reducing betaproteobacteria Azoarcus anaerobius and Thauera aromatica AR-1 use an oxidative mechanism to anaerobically degrade resorcinol and 3,5-dihydroxybenzoate (3,5-DHB), respectively, rendering hydroxyhydroquinone as intermediate. The first pathway step is performed by a dimethylsulphoxide-reductase family hydroxylase. The gene cluster coding for the pathway is homologous in these strains.
View Article and Find Full Text PDFToxic polycyclic aromatic hydrocarbons (PAHs) are frequently released into the environment from anthropogenic sources. PAH remediation strategies focus on biological processes mediated by bacteria. The availability of oxygen in polluted environments is often limited or absent, and only bacteria able to thrive in these conditions can be considered for bioremediation strategies.
View Article and Find Full Text PDFAlthough bacterial anaerobic degradation of mono-aromatic compounds has been characterized in depth, the degradation of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene has only started to be understood in sulfate reducing bacteria, and little is known about the anaerobic degradation of PAHs in nitrate reducing bacteria. Starting from a series of environments which had suffered different degrees of hydrocarbon pollution, we used most probable number (MPN) enumeration to detect and quantify the presence of bacterial communities able to degrade several PAHs using nitrate as electron acceptor. We detected the presence of a substantial nitrate reducing community able to degrade naphthalene, 2-methylnaphthalene (2MN), and anthracene in some of the sites.
View Article and Find Full Text PDFThe accident of the Prestige oil tanker in 2002 contaminated approximately 900 km of the coastline along the northern Spanish shore, as well as parts of Portugal and France coast, with a mixture of heavy crude oil consisting of polycyclic aromatic hydrocarbons, alkanes, asphaltenes and resins. The capacity of the autochthonous bacterial communities to respond to the oil spill was assessed indirectly by determining the hydrocarbon profiles of weathered oil samples collected along the shore, as well as through isotope ratios of seawater-dissolved CO2, and directly by analyses of denaturing gradient gel electrophoresis fingerprints and 16S rRNA gene libraries. Overall, the results evidenced biodegradation of crude oil components mediated by natural bacterial communities, with a bias towards lighter and less substituted compounds.
View Article and Find Full Text PDFThis pilot study was conducted to evaluate the occurrence of Clostridium difficile in samples of ground meat in Sweden. From April to September 2008, 82 meat samples were collected from randomly selected retail shops in Uppsala County (central Sweden). C.
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