Microbial Community Structure and Functions in Ethanol-Fed Sulfate Removal Bioreactors for Treatment of Mine Water.

Sulfate-rich mine water must be treated before it is released into natural water bodies. We tested ethanol as substrate in bioreactors designed for biological sulfate removal from mine water containing up to 9 g L-1 sulfate, using granular sludge from an industrial waste water treatment plant as inoculum. The pH, redox potential, and sulfate and sulfide concentrations were measured twice a week over a maximum of 171 days. The microbial communities in the bioreactors were characterized by qPCR and high throughput amplicon sequencing. The pH in the bioreactors fluctuated between 5.0 and 7.7 with the highest amount of up to 50% sulfate removed measured around pH 6. Dissimilatory sulfate reducing bacteria (SRB) constituted only between 1% and 15% of the bacterial communities. Predicted bacterial metagenomes indicated a high prevalence of assimilatory sulfate reduction proceeding to formation of l-cystein and acetate, assimilatory and dissimilatory nitrate reduction, denitrification, and oxidation of ethanol to acetaldehyde with further conversion to ethanolamine, but not to acetate. Despite efforts to maintain optimal conditions for biological sulfate reduction in the bioreactors, only a small part of the microorganisms were SRB. The microbial communities were highly diverse, containing bacteria, archaea, and fungi, all of which affected the overall microbial processes in the bioreactors. While it is important to monitor specific physicochemical parameters in bioreactors, molecular assessment of the microbial communities may serve as a tool to identify biological factors affecting bioreactor functions and to optimize physicochemical attributes for ideal bioreactor performance.

Sulphate removal from mine water with chemical, biological and membrane technologies.

Chemical, physical and biological technologies for removal of sulphate from mine tailings pond water (8 g SO42-/L) were investigated. Sulphate concentrations of approximately 1,400, 700, 350 and 20 mg/L were obtained using gypsum precipitation, and ettringite precipitation, biological sulphate reduction or reverse osmosis (RO) after gypsum pre-treatment, respectively. Gypsum precipitation can be widely utilized as a pre-treatment method, as was shown in this study. Clearly the lowest sulphate concentrations were obtained using RO. However, RO cannot be the only water purification technology, because the concentrate needs to be treated. There would be advantages using biological sulphate reduction, when elemental sulphur could be produced as a sellable end product. Reagent and energy costs for 200 m3/h tailings pond water feed based on laboratory studies and process modelling were 1.1, 3.1, 1.2 and 2.7 MEur/year for gypsum precipitation, ettringite precipitation, RO and biological treatment after gypsum precipitation, respectively. The most appropriate technology or combination of technologies should be selected for every industrial site case by case.

Caveolar transport through nasal epithelium of birch pollen allergen Bet v 1 in allergic patients.

BACKGROUND: Previous work in type I pollen allergies has focused on aberrant immunoresponses. OBJECTIVE: Our systems-level analyses explore the role of epithelium in early pathogenesis of type I allergic reactions. METHODS: We began top-down analyses of differences in human nasal epithelial cells and biopsy specimens obtained from patients with birch allergy and healthy control subjects in the resting state and after intranasal in vivo birch pollen challenges. Immunohistochemistry, immunotransmission electron microscopy, mass spectrometry, transcriptomics, and integration of data to a pathway were conducted. RESULTS: Bet v 1 allergen bound to epithelium immediately after in vivo birch pollen challenge during winter only in allergic individuals. It also travelled through epithelium with caveolae to mast cells. Sixteen unique proteins were found to bind to the Bet v 1 column only in lysates from allergic epithelial cells; 6 of these were caveolar and 6 were cytoskeletal proteins. The nasal epithelial transcriptome analysis from allergic and healthy subjects differed during the winter season, and these subjects also responded differentially to birch pollen challenge. Within this pollen-induced response, the gene ontology categories of cytoskeleton and actin cytoskeleton were decreased in allergic patients, whereas the actin-binding category was enriched in healthy subjects. Integration of microscopic, mass spectrometric, and transcriptomic data to a common protein-protein binding network showed how these were connected to each other. CONCLUSION: We propose a hypothesis of caveolae-dependent uptake and transport of birch pollen allergen in the epithelium of allergic patients only. Application of discovery-driven methodologies can provide new hypotheses worth further analysis of complex multifactorial diseases, such as type I allergy.