It is also observed that all systems exhibited low mineralization rates, with the chlorination process being slightly more efficient in promoting the degradation, whereas the ozonation was more efficient in promoting the mineralization of metformin. Based on these results a route for the chlorination, photodegradation and ozonation of MTF, which comprised of its successive oxidation in the aqueous medium, could be proposed. It could also be concluded that the treated samples were not cytotoxic to HepG2 cells in a MTT assay. Copyright © 2016 John Wiley & Sons, Ltd.

Mayaro virus (MAYV) is a neglected tropical arbovirus that causes a febrile syndrome that is sometimes accompanied by incapacitating arthritis/arthralgia. The pathogenesis of MAYV has not been completely defined and oxidative stress mediated by an increase in reactive oxygen species (ROS) and/or depletion of antioxidant defences has been found to contribute to several aspects of viral disease. To investigate whether MAYV induced oxidative stress in host cells, we monitored ROS production, oxidative stress markers and antioxidant defences at different time points after infection. Our results show that MAYV induced significant oxidative stress in infected HepG2 cells, as indicated by the increase of malondialdehyde (MDA) and protein carbonyl levels, and by a significant decrease of the reduced versus oxidized glutathione (GSH/GSSG) ratio. Generally, MAYV-infected HepG2 cells also showed an increase in antioxidant defences. We observed an increase in the superoxide dismutase (SOD) and catalase (CAT) activities and the total glutathione content. To determine whether similar effects occurred in other cell types, we evaluated the ROS, MDA and SOD activity levels in J774 cells after MAYV infection. Similar to our observations in HepG2 cells, the J774 cells showed an increase in ROS, MDA and total SOD activity following MAYV infection. Thus, since the cellular redox environment is influenced by the production and removal of ROS, we hypothesize that the overproduction of ROS was responsible for the oxidative stress in response to the MAYV infection despite the increase in the antioxidant status. This study is the first report on the involvement of oxidative stress during MAYV infection. Collectively, our data shed light on some mechanisms that are operational in host cells following exposure to MAYV.

The diversity of sulphate-reducing bacteria (SRB) was investigated in sediments along environmental gradients in the River Colne estuary, Essex, UK. DNA samples were collected from four sites; marine-dominated (Alresford Creek), brackish (the Hythe), predominantly freshwater (East Hill Bridge) and freshwater (the Weir) between September 2001 and May 2002. SRB community composition was assessed by PCR amplification, cloning and sequencing of part of the α subunit of dissimilatory sulphite reductase (dsrA) using directly extracted sediment DNA. The majority of the dsrA sequences were associated with members of the Desulfobacteraceae family, the Desulfobulbaceae family and a deeply branched group in the dsrA tree with no cultured representatives. There was some evidence of a salinity-related distribution within both the Desulfobacteraceae and Desulfobulbaceae groups. Clones related to Desulfotomaculum of the xenologues Firmicutes and a phylogenetically distinct Colne group 3 were detected only at the freshwater East Hill Bridge and Weir sites. Conversely, clones related to an uncultured group (Colne group 1) were found only at the marine and brackish sites. A statistical analysis of composition revealed that dsrA sequences from the marine-dominated Alresford Creek and the brackish site at the Hythe were not significantly different from each other (P>0.05), but were significantly different from those of the freshwater-dominated East Hill Bridge and the Weir (P<0.05). The sequences from East Hill Bridge and the Weir were not significantly different from each other (P>0.05). The data presented show a complex distribution of SRB along the estuary with some evidence to support the idea that salinity and sulphate concentrations are an important factor in determining SRB community structure.Key words: dissimilatory sulphite reductase gene, environmental gradients, estuarine sediment, sulphate reduction Sulphate reduction is an important process involved in both the global carbon and sulphur cycles. This process can dominate anaerobic terminal mineralisation of organic matter in high-sulphate sediments, degrading up to 50% of all organic matter in coastal marine sediments 12) and plays a minor but still important role in low-sulphate sediments 26,38) . Rates of sulphate reduction vary in relation to temperature and electron donor and acceptor concentrations with the availability of sulphate an important factor in the control of the rate of sulphate reduction. Sulphate concentrations range from approximately 25 mM in full-strength seawater to <0.2 mM in freshwater 7) . Freshwater-adapted sulphatereducing bacteria (SRB) have a greater affinity for sulphate (K m =5-68 µM) than marine-adapted SRB (K m =200 µM) 8,37) , allowing them to continue sulphate reduction at much lower sulphate concentrations than marine SRB. Physiological differences between freshwater-and marine-adapted SRB may be reflected in differences in species or phylogenetic compositions of SRB communities.The Colne estuary is a small, muddy, macrotidal (3 to 5...

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This work investigated the anaerobic degradation of the model azo dye Remazol Yellow Gold RNL in an upflow anaerobic sludge blanket reactor (UASB) and two submerged anaerobic membrane (SAMBR) bioreactors, one of which (SAMBR-1) was operated with powdered activated carbon (PAC) in its interior. The reactors were operated at 35 °C with a hydraulic retention time of 24 h in three operational phases, aimed to assess the effect of external sources of carbon (glucose) or redox mediator (yeast extract) on the removal or color and organic matter. The results showed that removal efficiencies of COD (73-94%) and color (90-94%) were higher for SAMBR-1 when compared to SAMBR-2 (operated without PAC) and UASB reactors. In addition, the presence of PAC in SAMBR-1 increased reactor stability, thereby leading to a lower accumulation of volatile fatty acids (VFA). The microfiltration membrane was responsible for an additional removal of ~50% of soluble residual COD in the form of VFA, thus improving permeate quality. On its turn, PAC exhibited the ability to adsorb byproducts (aromatic amines) of azo dye degradation as well as to act as source of immobilized redox mediator (quinone groups on its surface), thereby enhancing color removal.