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Bioaugmentation (the process of adding selected strains/mixed cultures to wastewater reactors to improve the catabolism of specific compounds, e.g. refractory organics, or overall COD) is a promising technique to solve practical problems in wastewater treatment plants, and enhance removal efficiency. The potential of this option can now be enhanced in order to take advantage of important advances in the fields of microbial ecology, molecular biology, immobilization techniques and advanced bioreactor design. Reports on bioaugmentation in WWT show the difficulties in evaluating the potential parameters involved, leading frequently to inconclusive outcomes. Many studies have been carried out on the basis of trial-and-error approaches, and it has been reported that reactors bioaugmented with pure cultures often fail to perform as well as the pure cultures under laboratory conditions. As an interesting technical challenge, the feasibility of bioaugmentation should ultimately be assessed by data from field implementation, and this review highlights several promising areas to explore in the future.

Despite worldwide prevalence of superficial mycoses, the immune response in dermatophytosis has scarcely been investigated. In this study, we developed a model of superficial skin infection in C57BL/6 mice with Microsporum canis, a highly prevalent human pathogen. This model mimics mild inflammatory human dermatophytosis, characterized by neutrophil recruitment and fungal invasion limited to the epidermis and exhibits the establishment of a specific T helper type 17 immune response during infection. By using IL-17RA- or IL-17A/F-deficient mice we showed that, in the absence of a functional IL-17 pathway, M. canis extensively colonizes the epidermis and promotes an exaggerated skin inflammation and a shift to an IFN-γ-mediated (T helper type 1) response. IL-17 signaling was not involved in neutrophil influx to skin or fungal invasion to deeper tissues. Finally, this study shows that skin langerin-expressing cells contribute to the antifungal T helper type 17 response in vivo. In conclusion, these data directly show a dual function of IL-17 cytokines in dermatophytosis by controlling superficial infection and down-modulating a T helper type 1 antifungal response.

Flow cytometry (FC) has been introduced to characterize and to assess the physiological states of microorganisms in conjunction with the classical plate-counting method. To show the applicability of the technique, in particular for the development of kinetic models, pure culture fermentation experiments were followed over time, using both prokaryotic (Lactobacillus hilgardii) and eukaryotic (Saccharomyces cerevisiae) microorganisms growing in standard culture media (MRS and YPD). The differences observed between the active and viable cells determined by FC and CFU, respectively, allowed us to determine that a large number of cells were in a viable but nonculturable (VBNC) state, which resulted in a subpopulation much larger than the damaged-cell (double-stained) subpopulation. Finally, the determination of the evolution of viable, the VBNC, and the dead cells allowed us to develop a segregated kinetic model to describe the yeast and the bacteria population dynamics and glucose consumption in batch cultures. This model, more complete than that which is traditionally used, based only on viable cell measurements, describes better the behavior and the functionality of the cultures, giving a deeper knowledge in real time about the status and the course of the bioprocesses.

Bacteriophage #393-A2, isolated from an artisanal cheese whey sample, is a temperate phage able to generate stable lysogens through integration of its DNA into the bacterial genome. One-step growth kinetics of its lytic development revealed eclipse and latent periods of 100 and 140 min, respectively, with a burst size of about 200 p.f.u. per infected cell. #393-A2 virions have an isometric head and a long, non-contractile tail terminating in a baseplate. The capsid is composed of two major and at least nine minor structural polypeptides. The phage genome consists of a double-stranded DNA molecule of 44 kbp bearing 3'-protruding cohesive ends. A physical map of the phage DNA has been constructed for six restriction enzymes. The whole 4393-A2 genome has been cloned in Escherichia coli using plasmid-and phagederived cloning vectors.

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Analysis of microbiological samples from fermentation processes in the beverage industry (beer, wine, and cider) by traditional indirect, culture-based standard methods is timeconsuming, and the methods do not produce direct information about the physiological state of the microorganisms. Moreover, the plate-counting method detects only cells able to form colonies under the conditions of the medium that is used, ignoring the presence of cells that do not form colonies but are nevertheless metabolically active (6). As is known, standard laboratory culture media rarely resemble natural environmental conditions (32). The application of flow cytometry (FC) with fluorescent dyes is faster and more direct and has made it possible to distinguish stages beyond the classical definition of viability generally demonstrated by culturing (24). FC can be used to quantitatively measure the optical characteristics of cells as they pass, in single file, into a focused beam of light (for a review, see reference 33). As particles pass through the beam, three parameters are measured: forward light scatter, side angle light scatter, and fluorescence at selected wavelengths. Light scatter is related to cell mass, structure, surface properties, and the optical density of the internal medium. A variety of fluorescent dyes may be used to detect structural or functional cellular properties. In this way, different cellular functions, such as reproductive growth, metabolic activity, and membrane integrity, can be detected, allowing a definition of the term viable-but-not-culturable cells (VBNC) (24) (other authors have called them active but nonculturable). Previous studies have reported that there are two major adaptations that cells undergo during the formation of VBNC states: cell wall toughening and DNA condensation (29). The detection of metabolic activity provides presumptive evidence of reproductive growth by the demonstration of enzyme activity, such as esterases, along with membrane integrity. In the absence of metabolic activity, it is still possible to determine membrane integrity by either dye retention or dye exclusion, the latter using propidium iodide (PI). Cells without an intact membrane cannot maintain or generate the electrochemical gradient that generates the membrane potential and can be considered dead cells (24). The use of FC techniques was reported for the "at-line" study of Escherichia coli fermentations (14), which detected a considerable drop in cell viability (about 20%) during the latter stages of small-scale (5-liter), well-mixed fedbatch fermentations.Flow-cytometric applications using different dyes have been compared to standard methods to assess yeast cultures in baking, wine making, cider making, and brewing (1,5,7,8,10,11,17,19). The technique has also been used to study the membrane integrity of ethanol-stressed Oenococcus oeni cells (9). Most studies of FC applications have focused mainly on microorganims as pure cultures, and only a small number have analyzed mixed populations over time (30).The purp...