The microbial community composition of a nitrifying-denitrifying activated sludge from an industrial sewage treatment plant analyzed by the full-cycle rRNA approach

The composition of the microbial community present in the nitrifying-denitrifying activated sludge of an industrial wastewater treatment plant connected to a rendering facility was investigated by the full-cycle rRNA approach. After DNA extraction using three different methods, 94 almost full-length 16S rRNA gene clones were retrieved and analyzed phylogenetically. 59% of the clones were affiliated with the Proteobacteria and clustered with the beta- (29 clones), alpha- (24), and delta-class (2 clones), respectively. 15 clones grouped within the green nonsulfur (GNS) bacteria and 11 clones belonged to the Planctomycetes. The Verrucomicrobia, Acidobacteria, Nitrospira, Bacteroidetes, Firmicutes and Actinobacteria were each represented by one to five clones. Interestingly, the highest 'species richness' [measured as number of operational taxonomic units (OTUs)] was found within the alpha-class of Proteobacteria, followed by the Planctomycetes, the beta-class of Proteobacteria, and the GNS-bacteria. The microbial community composition of the activated sludge was determined quantitatively by using 36 group-, subgroup-, and OTU-specific rRNA-targeted oligonucleotide probes for fluorescence in situ hybridization (FISH), confocal laser scanning microscopy and digital image analysis. 89% of all bacteria detectable by FISH with a bacterial probe set could be assigned to specific divisions. Consistent with the 16S rRNA gene library data, members of the beta-class of Proteobacteria dominated the microbial community and represented almost half of the biovolume of all bacteria detectable by FISH. Within the beta-class, 98% of the cells could be identified by the application of genus- or OTU-specific probes demonstrating a high in situ abundance of bacteria related to Zoogloea and Azoarcus sensu lato. Taken together, this study provides the first encompassing, high-resolution insight into the in situ composition of the microbial community present in a full-scale, industrial wastewater treatment plant.     

High water users can be drought tolerant: using physiological traits for green roof plant selection

Background and aims

Green roofs are often installed to reduce urban stormwater runoff. To optimally achieve this, green roof plants need to use water when available, but reduce transpiration when limited to ensure survival. Succulent species commonly planted on green roofs do not achieve this. Water availability on green roofs is analogous to natural shallow-soil habitats including rock outcrops. We aimed to determine whether granite outcrop species could improve green roof performance by evaluating water use strategies under contrasting water availability.

Methods

Physiological and morphological responses of 12 granite outcrop species with different life-forms (monocots, herbs and shrubs) and a common green roof succulent were compared in well watered (WW) and water deficit (WD) treatments.

Key results

Granite outcrop species showed a variety of water-use strategies. Unlike the green roof succulent all of the granite outcrop species showed plasticity in water use. Monocot and herb species showed high water use under WW but also high water status under WD. This was achieved by large reductions in transpiration under WD. Maintenance of water status was also related to high root mass fraction.

Conclusions

By developing a conceptual model using physiological traits we were able to select species suitable for green roofs. The ideal species for green roofs were high water users which were also drought tolerant.     

Effect of H. pylori on the expression of TRAIL, FasL and their receptor subtypes in human gastric epithelial cells and their role in apoptosis

BACKGROUND AND AIMS: In the human stomach expression of TNF-related apoptosis inducing ligand (TRAIL) and its receptors and the modulatory role of Helicobacter pylori are not well described. Therefore, we investigated the effect of H. pylori on the expression of TRAIL, FasL and their receptors (TRAIL-R1-R4, Fas) in gastric epithelial cells and examined their role in apoptosis. MATERIALS AND METHODS: mRNA and protein expression of TRAIL, FasL and their receptors were analyzed in human gastric epithelial cells using RT-PCR, Western blot, and immunohistochemistry. Gastric epithelial cells were incubated with FasL, TRAIL and/or H. pylori, and effects on expression, cell viability and epithelial apoptosis were monitored. Apoptosis was analyzed by histone ELISA, DAPI staining and immunohistochemistry. RESULTS: TRAIL, FasL and their receptor subtypes were expressed in human gastric mucosa, gastric epithelial cell primary cultures and gastric cancer cells. TRAIL, FasL and H. pylori caused a time- and concentration-dependent induction of DNA fragmentation in gastric cancer cells with synergistic effects. In addition, H. pylori caused a selective up-regulation of TRAIL, TRAIL-R1 and Fas mRNA and protein expression in gastric cancer cells. CONCLUSIONS: Next to FasL and Fas, TRAIL and all of its receptor subtypes are expressed in the human stomach and differentially modulated by H. pylori. TRAIL, FasL and H. pylori show complex interaction mediating apoptosis in human gastric epithelial cells. These findings might be important for the understanding of gastric epithelial cell kinetics in patients with H. pylori infection.     

The association between exposure determined by radiofrequency personal exposimeters and human exposure: A simulation study

The selection of an adequate exposure assessment approach is imperative for the quality of epidemiological studies. The use of personal exposimeters turned out to be a reasonable approach to determine exposure profiles, however, certain limitations regarding the absolute values delivered by the devices have to be considered. Apart from the limited dynamic range, it has to be taken into account that these devices give only an approximation of the exposure due to the influence of the body of the person carrying the exposimeter, the receiver characteristics of the exposimeter, as well as the dependence of the measured value on frequency band, channel, slot configuration, and communication traffic. In this study, the relationship between the field strength measured close to the human body at the location of the exposimeter and the exposure, that is, the field strength at the location of the human body without the human body present, is investigated by numerical means using the Visible Human model as an anatomical phantom. Two different scenarios were chosen: (1) For FM, GSM, and UMTS an urban outdoor scenario was examined that included a transmitting antenna mounted on the roof of one of four buildings at a street crossing, (2) For WLAN an indoor scenario was investigated. For GSM the average degree of underestimation by the exposimeter (relation of the average field levels at the location of the exposimeter to the field level averaged over the volume of the human body without the body present) was 0.76, and for UMTS 0.87; for FM no underestimation was found, the ratio was 1. In the case of WLAN the degree of underestimation was more pronounced, the ratio was 0.64. This study clearly suggests that a careful evaluation of correction factors for different scenarios is needed prior to the definition of the study protocol. It has to be noted that the reference scenario used in this study does not allow for final conclusions on general correction factors. Bioelectromagnetics 31:535–545, 2010. © 2010 Wiley‐Liss, Inc.     

Differential effects of N-glycans on surface expression suggest structural differences between the acid-sensing ion channel (ASIC) 1a and ASIC1b

ASICs (acid-sensing ion channels) are H(+)-gated Na(+) channels with a widespread expression pattern in the central and the peripheral nervous system. ASICs have a simple topology with two transmembrane domains, cytoplasmic termini and a large ectodomain between the transmembrane domains; this topology has been confirmed by the crystal structure of chicken ASIC1. ASIC1a and ASIC1b are two variants encoded by the asic1 gene. The variable part of the protein includes the cytoplasmic N-terminus, the first transmembrane domain and approximately the first third of the ectodomain. Both variants contain two consensus sequences for N-linked glycosylation in the common, distal part of the ectodomain. In contrast with ASIC1a, ASIC1b contains two additional consensus sequences in the variable, proximal part of the ectodomain. Here we show that all the extracellular asparagine residues within the putative consensus sequences for N-glycosylation carry glycans. The two common distal glycans increase surface expression of the channels, but are no absolute requirement for channel activity. In sharp contrast, the presence of at least one of the two proximal glycans, which are specific to ASIC1b, is an absolute requirement for surface expression of ASIC1b. This result suggests substantial differences in the structure of the proximal ectodomain between the two ASIC1 variants.     

Spatial-pattern analysis in a territorial spider: evidence for multi-scale effects

Territorial animals maintain a certain distance to neighbouring conspecifics, presumably leading to a regular spatial pattern through social spacing. Nevertheless, most animal populations are assumed to show aggregation at certain distance ranges, reflecting the scale dependency of spatial patterns. Leucorchestris arenicola (Araneae: Sparassidae) is a burrow-living spider species that shows territorial behaviour against conspecifics. A multi-scale approach in spatial analysis revealed that territory owners had fewer neighbours than expected under spatial randomness at distances up to 6 m. Behavioural field experiments showed that territory owners were able to perceive and react to burrow constructing neighbours up to at least 4 m distance from their own burrow. At larger distances individuals were often more aggregated than expected under spatial randomness. Analysing adult and immature relationships showed attraction between different development stages at small distances and avoidance at larger distances. The analysis reveals diverse spatial patterns in a territorial and cannibalistic species, showing that both behaviour and environment affect pattern development at different distances. The study outlines the importance of multi-scale approaches for spatial analysis and the need for accompanying experiments to facilitate the interpretation of results.     

Plant-based production of biopharmaceuticals

Plants are now gaining widespread acceptance as a general platform for the large-scale production of recombinant proteins. The first plant-derived recombinant pharmaceutical proteins are reaching the final stages of clinical evaluation, and many more are in the development pipeline. Over the past two years, there have been some notable technological advances in this flourishing area of applied biotechnology, as shown by the continuing commercial development of novel plant-based expression platforms. There has also been significant success in tackling some of the limitations of plant bioreactors, such as low yields and inconsistent product quality, that have limited the approval of plant-derived pharmaceuticals.     

Can we measure ecological sustainability? Landscape pattern as an indicator for naturalness and land use intensity at regional,national and European level

European landscapes have been shaped over the centuries by processes related to human land use, which are reflected in regionally distinct landscape patterns. Since landscape pattern has been linked to biodiversity and other ecological values of the landscapes, this paper explores landscape pattern as a tool for ecological sustainability assessments at the regional (Austrian Cultural Landscapes), national (Austria) and European (European Union + Norway, Switzerland) level with focus on agricultural landscapes. A set of landscape metrics served as a basis to assess naturalness and geometrisation of Austrian and European landscapes as a proxy for their sustainability. To achieve an accurate spatially explicit assessment, we applied a spatial reference framework consisting in units that are homogeneous in biophysical and socio-economic contexts, adapted the regional approach for its application at European level, and developed relative sustainability thresholds for the landscape metrics. The analyses revealed that several landscape metrics, particularly the “Number of Shape Characterising Points” showed a high correlation with the degree of naturalness. The sustainability map of Austria based on an ordinal regression model revealed well-known problem regions of ecological sustainability. At the European level, the relative deviation from the average pattern showed clearly the simplification processes in the landscapes. However, a better spatial resolution of land cover data would add to the refinement of pattern analysis in regions and therefore the assessment of sustainability. We recommend the combination of information of different scales for the formulation and implementation of sustainability policies.     

The chimeric cytokine Hyper-IL-6 enhances the efficiency of lentiviral gene transfer in hepatocytes both in vitro and in vivo

Lentiviral vectors have been used for gene transfer into the liver but their ability to efficiently transduce quiescent hepatocytes remains controversial. Lentivirus-mediated gene transfer is more efficient in cycling cells. We determine the effect of H-IL6 in the lentiviral transduction. The lentiviral vector was used to transduce HepG2 cells and mice liver cells, previously treated with H-IL6. The highest transduction level was observed in HepG2 cells treated with 30 ng/mL H-IL6 and in the mice that received 4 μg H-IL6. Our results suggest that H-IL6 is an inducer of lentiviral gene transfer into the liver cells without any toxicity.