This study aimed to isolate and characterize a microbial culture able to degrade sulfonamides. Sulfamethoxazole (SMX)-degrading microorganisms were enriched from activated sludge and wastewater. The resultant mixed culture was composed of four bacterial strains, out of which only Achromobacter denitrificans PR1 could degrade SMX. This sulfonamide was used as sole source of carbon, nitrogen and energy with stoichiometric accumulation of 3-amino-5-methylisoxazole. Strain PR1 was able to remove SMX at a rate of 73.6 ± 9.6 µmolSMX/gcell dry weight h. This rate more than doubled when a supplement of amino acids or the other members of the mixed culture were added. Besides SMX, strain PR1 was able to degrade other sulfonamides with anti-microbial activity. Other environmental Achromobacter spp. could not degrade SMX, suggesting that this property is not broadly distributed in members of this genus. Further studies are needed to shed additional light on the genetics and enzymology of this process.

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This work was aimed at enumerating the viable microorganisms in ripened Serra da Estrela cheeses, manufactured from both refrigerated and non-refrigerated milk, in various dairies located throughout the demarcated region. Scanning electron microscopy was used to analyze the microstructure, and thus aid in understanding possible differences in their microbiological profile. The cheeses were allowed to ripen under controlled conditions, and sampled at 60, 90, 120, 150 and 180 d following manufacture. Viable numbers of lactic acid bacteria, staphylococci, Enterobacteriaceae and yeasts were obtained following standard plate counting on a number of selective media. Lactococcus was the most abundant genus (above 10 8 cfu g À1 of cheese) up to 120 d of ripening. No significant microstructural differences were observed in cheeses manufactured in different dairies over the ripening process. However, microstructural differences were apparent between cheeses manufactured with refrigerated versus non-refrigerated milk. r

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Aqueous extracts obtained from cell suspension cultures of Centaurea calcitrapa were used as proteolytic additive in the manufacture of a commercial bovine cheese, coagulated with animal rennet and typically ripened for 28 d. The cheese was assessed in comparison to standard cheese for two levels of addition of said extract, viz. 0.61 and 1.22 mg of total protein mL\. The qualitative and quantitative evolutions of the nitrogen fractions were monitored in the experimental cheeses throughout the whole ripening period. In general, the chemical compositions of the cheeses were di!erent depending on the amount of extract used, but no signi"cant di!erences could be detected in the ripening index. With regard to electrophoretic pro"les, the two types of cheese could be distinguished until up to ca. 7 d of ripening, but di!erences did essentially vanish by 28 d.

Despite its relevance to sensory features and to fundamental explanation of the changes observed throughout cheese ripening, microstructural studies of specialty cheeses have lagged far behind those of industrialized cheeses. Hence, the purpose of this study was to pinpoint microstructural differences in the gel network of traditional Serra da Estrela cheese throughout ripening, using 2-dimensional image analysis, and to unfold correlations of such microstructural indicators with classical bulk chemical and textural parameters. Hence, samples were taken throughout the ripening period, following a nested design; uniform thin sections were systematically observed via light microscopy (LM, 200 ×) and transmission electron microscopy (TEM, 4,400 ×), and computer-assisted quantitative analysis of digital images was comprehensively performed following standard stereological methodology. Fresh cheeses exhibited the highest porosity and ratio of surface area to volume. Significant negative correlations were found between microstructural parameters and proteolysis indicators. Light microscopy images suggested that rearrangements exist, up to 21 d, of the cheese matrix that leave porosity and pores unchanged, whereas TEM images indicated a significant decrease in number of pores within the same time frame, especially those above 1 × 10(-2) μm(2) in area. The larger pores, chiefly with cross-sectional areas above 40 μm(2), were less represented by the end of ripening-and likely explain the observed significant decrease of cheese porosity without a change in number of pores. Field viewing significantly affected the microstructural parameter values, whereas section viewing affected significantly only LM-based ones. Categorical principal component analysis between the 2 types of microstructural data sets was performed, and permitted discrimination of each stage of ripening. Multiple linear regression analysis indicated that the variables associated with the nitrogen fraction were well predicted by stereological-based parameters (R(2) ≥ 0.96). Therefore, our findings demonstrate the potential of image analysis to monitor microstructure throughout ripening, and that the microstructure revealed by LM reflects more clearly cheese aging than that revealed by TEM.

Our major goal was the physicochemical, biochemical and microbiological characterization of Cobrançosa table olives, as support for the eventual granting of a PDO status. Seven producers were accordingly sampled throughout eleven months. Brines were analyzed for pH, salinity, acidity, and organic and phenolic compounds. Yeasts and Latic Acid Bacteria (LAB) were enumerated, and the dominant strains duly identified. Despite process variabilities, two stages appear to be shared by all manufacturers: sweetening—the renewal of water to remove bitter compounds; and salting—gradual addition of salt to brine for preservation. Yeasts dominated during sweetening, but LAB tended to be similar in viable counts (7 log CFU/mL) by the end of salting. Lactiplantibacillus (Lpb.) pentosus, Lpb. paraplantarum, Pediococcus parvulus, and Oenococcus kitaharae were the most abundant LAB found, together with an average pH of 4.1 and 6–9% for salt content. All organic acids exhibited an inverted parabolic evolution, with maxima of 3450 mg/L for lactic and 4000 mg/L for succinic by 3 months, and 2750 mg/L for acetic and 2950 mg/L for citric by 4 months. Oleuropein levels were affected by the frequency of brine renewal but decreased from 1350 to 700 mg/L, with hydroxityrosol and tyrosol increasing from 10 to 2000 mg/L and 2 to 550 mg/L, respectively, within 11 months.

Chitosan-impregnated gutta-percha points (ChitGPP) were tested for their ability to inhibit the growth of microorganisms usually involved in root canal infections. Their mechanical properties were also studied and compared with the commonly used commercial points in endodontics. ChitGPP were more efficient in reducing the microbial load than those without chitosan. ChitGPP also possess better tensile and elastic properties than commercial ones. After six months of storage, ChitGPP's were still able to reduce the bacterial load by 1 log, suggesting that impregnation of gutta-percha points with chitosan could be a good alternative to obtain gutta-percha points with improved antimicrobial properties.