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Leipzig, Germany

Mehlig L.,Universitatsklinikum Carl Gustav Carusklinik Und Poliklinik For Dermatologie | Petzold M.,bioMerieux | Heder C.,Universitatsklinikum Carl Gustav Carusklinik Und Poliklinik For Dermatologie | Gunther S.,Helmholtz Center for Environmental Research | And 4 more authors.
Journal of Environmental Engineering (United States) | Year: 2013

Enhanced biological phosphorous removal (EBPR) from wastewater has been successfully used for more than three decades and is considered to be an environmentally friendly wastewater-treatment process. Biologically, this process is realized by incorporation of phosphate as polyphosphate (polyP) granules in activated sludge bacteria. Important groups of bacteria responsible for P removal have been identified, but the full microbial diversity involved in this process is still unknown. This paper reports on the microbial composition of activated sludge communities in eight wastewater-treatment plants (WWTPs) with different sizes and modes of operation. The polyphosphate accumulating organisms (PAOs) within this complex biocenosis were identified by fluorescent dye staining and classified by in situ hybridization techniques. Of the bacteria in the aerobic basin, 5-13% contained polyP granules. In addition, flow cytometry was used to quantify PAOs after tetracycline staining and to separate these cells. The phylogenetic affiliation of the sorted PAOs was identified by cloning and sequencing. Both workflows showed similar outcomes. The majority of PAOs in all plants were Betaproteobacteria (22%), Actinobacteria (21%), and Alphaproteobacteria (12%), with differences in the relative abundance. In addition, Bacteroidetes (12%) were detected in the clone libraries, especially Haliscomenobacter, which should be considered further with regard to its influence on the EBPR process. The denaturing gradient gel electrophoresis analyses of sorted PAOs revealed a diverse community composition of Betaproteobacteria, Actinobacteria, and Rhodocyclales in the WWTPs. PAOs were present in EBPR and non-EBPR WWTPs, and no correlation in their abundance and phylogenetic composition to the mode of operation was revealed. This study shows that specific PAO communities existed in the various WWTPs, probably favored by the respective wastewater composition, including so far unvalued PAOs species, but their active contribution in the EBPR process remains to be investigated. © 2013 American Society of Civil Engineers. Source

Traitcheva N.,Bulgarian Academy of Science | Berg H.,Saxonian Academy of science
Bioelectrochemistry | Year: 2010

In order to increase the permeability of cell membranes for low doses of cytostatic drugs, two bioelectrochemical methods have been compared: (a) electric pore formation in the plasma membranes by single electric impulses (electroporation), and (b) reordering of membrane structure by alternating currents (capacitively coupled). These treatments were applied to human leukemic K-562 cells and human lymphoma U-937 cells, yielding apoptotic and necrotic effects, determinated by flow cytometry. Additional cell death occurs after exposure to light irradiation at wavelengths λ> 600 nm, of cells which were electroporated and had incorporated actinomycin-C or daunomycin (daunorubicine). It is observed that drug uptake after an exponentially decaying electroporation pulse of the initial field strength Eo = 1.4 kV/cm and pulse time constants in the time range 0.5-3. ms is faster than during PEMF-treatment, i.e., application of an alternating current of 16. kHz, voltage U< 100. V, I= 55 mA, and exposure time 20. min. However, at the low a.c. voltage of this treatment, more apoptotic and necrotic cells are produced as compared to the electroporation treatment with one exponentially decaying voltage pulse. Thus, additional photodynamic action appears to be more effective than solely drugs and electroporation as applied in clinical electrochemotherapy, and more effective than the noninvasive pulsed electromagnetic fields (PEMFs), for cancer cells in general and animals bearing tumors in particular. © 2010. Source

Seeing that extreme historical floods usually affected territories of multiple countries, their research and comparison are possible only on the basis of long-term international cooperation. Only the knowledge from more affected countries can generate a complex image of their significance and impacts. This applies also to two disastrous floods, which occurred in Central Europe in September and then again in November 1890. The two floods affected a number of Central European countries at the same time and their extent reached beyond their borders. Whereas the flood events of September 1890 were documented in details already in the past, the catastrophic flood of November 1890 is today in the Czech Republic practically without the attention of experts and this is why it is in the focus of our brief reminder. © INSTITUTE OF GEONICS ASCR, v.v.i. 2010. Source

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