Methanogenic degradation of hydroquinone and catechol via reductive dehydroxylation to phenol

Fermentative degradation of hydroquinone, catechol, and phenol was demonstrated with nearly-homogeneous mixed methanogenic cultures obtained from freshwater sediments and sewage sludge by enrichment with the respective phenolic substrates. Gram-negative short rods predominated in these cultures, together with hydrogen- and acetate-utilizirtg methanogens. Acetate and methane were the only degradation products. Bacteria enriched with hydroquinone or catechol also degraded phenol and p-hydroxy-benzoate, but not resorcinol or resorcylic acids. Phenol was formed as an intermediate during catechol and hydroquinone degradation, indicating that reductive dehydroxylation was the primary event in degradation of these substrates. Inhibition experiments with bromoethanesulfonate and acetylene indicated that catechol, hydroquinone, and phenol degradation depended on a syntrophic co-operation of fermenting bacteria and hydrogen-oxidizing methanogens

Growth of a facultative anaerobe under oxygen‐limiting conditions in pure culture and in co‐culture with a sulfate‐reducing bacterium

The occurrence and properties were studied of glucose‐metabolizing bacteria present in the anaerobic sediment 5–10 cm below the surface of an estuarine tidal mud‐flat. Of all these bacteria (104– 105 per g wet sediment) 80–90% were facultatively anaerobic species. Chemostat enrichments on glucose under aerobic, oxygen‐limited and alternately aerobic‐anaerobic conditions also yielded cultures dominated by facultative anaerobes. One of the dominant species, tentatively identified as a Vibrio sp., was studied in more detail under oxygen‐limiting conditions. Fermentative and respiratory metabolisms were found to operate simultaneously, and the ratio between the two was regulated by the extent of oxygen limitation. A small fraction of the acetate formed under such growth conditions was shown to be subsequently respired. A co‐culture was established of the Vibrio sp. and a sulfate‐reducing bacterium (Desulfovibrio HL21 ) in an aerated chemostat. The importance of these observations is discussed in relation to the role of facultative anaerobes in anaerobic habitats

Detection and Characterization of Hepatitis E Virus Genotype 3 in Wastewater and Urban Surface Waters in Germany

In highly populated areas, environmental surveillance of wastewater and surface waters is a key factor to control the circulation of viruses and risks for public health. Hepatitis E virus (HEV) genotype 3 is considered as an emerging pathogen in industrialized countries. Therefore, this study was carried out to determine the prevalence of HEV in environmental waters in urban and suburban regions in Germany. HEV was monitored in water samples using quantitative RT-PCR (RT-qPCR) and nested RT-PCR without or with virus concentration via polyethylene glycol precipitation or ultracentrifugation. By RT-qPCR, 84-100% of influent samples of wastewater treatment plants were positive for HEV RNA. Genotypes HEV-3c and 3f were identified in wastewater, with HEV-3c being the most prevalent genotype. These data correlate with subtypes identified earlier in patients from the same area. Comparison of wastewater influent and effluent samples revealed a reduction of HEV RNA of about 1 lo