Use of a modified Gompertz equation to model synthetic dye decolourization by yeasts in liquid media

Forty six yeast strains isolated from two wastewater treatment stations along with other 81 cheese isolates were compared on their ability to decolorize five textile dyes in solid media. After a screening methodology that included liquid culture decoulorisation ability evaluation, yeasts isolates, LIII S 36 and L III ST 7 presented the best performance in the decolourisation for the five dyes tested: Remazol Black BA, Remazol Yellow RR, Levafix Blue CA, Remazol Brilliant Blue R and Levafix® Red CA).A modified Gompertz equation was used to model the decolourisation in liquid media; the estimated parameters, which all have biological attribution, allow us to assess quantitatively the decolourisation and a more accurate comparison between the different behaviours of the strains for each dye.Molecular biology methodologies also allowed the identification and the confirmation of the differences between the strains previous selected to liquid decolourisation based on classic methodologies. For the isolates from the wastewater treatment stations, we had a variety of different species identifications, such as Candida ortopsilosis, Debaromyces hansenii and for a small group of strains it should be necessary explore other methodologies of identification to obtain a correct identification. For the two strains with the best performance (L III S 36 and strain L III ST 7) were performed spectral scanning, is possible observe that, depending on the dye, the strains exhibit different behaviours in the decolourisation process, can achieve it through mechanisms of adsorption or due true degradation. Both strains produce extracellular manganese peroxidase. After 36 hours of incubation for the strain L III ST 7 and L III S 36 an average of 2.30 and 2.06 IU. l-1 of manganese peroxidase activity were detected, respectively. Due to the obvious morphological differences between filamentous fungi and yeasts, the enzymatic activities detected for the yeasts are interesting. Based on the results obtained it is possible to postulate that the decolourisation may be related with the MnP enzymatic activity.info:eu-repo/semantics/publishedVersio

Innovative biotechnology solutions for black stain removal and preventive conservation of historical and culturally important mural paintings

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Toward a circular bioeconomy: extracting cellulose from grape stalks

The purpose of this study was to assess the extraction of cellulose from stalks of vines using auto-hydrolysis and characterize it. As the results obtained, the colorimeter readings displayed a final yellow color of the fiber, demonstrating that the bleaching process was insufficient and that multiple bleaching processes might be required. According to the FTIR (Fourier-transform infrared spectroscopy) data, there were stretching and deformation vibrations of characteristic peak that represent cellulose (2900, 1500, and 1200 cm−1). Although lignin and hemicellulose were partially removed according to the FTIR, distinct cellulose yields were achieved for each fraction, including fractions 500, 300, 250, 150 µm, and retain, with values of 21.98, 12.70, 7.20, 5.74, and 3.11%, respectively. In sum, we were able to extract cellulose from the stalk vine, although the last step still needs to be optimized for better whitening.info:eu-repo/semantics/publishedVersio

GIS technology for documentation of wall paintings in northern Portugal with a dark stain phenomenon

We often come across a problem of deterioration in some 15th and 16th century mural painting (MP) ensembles on the inner walls of granitic Romanesque religious buildings in the north of Portugal (fig. 1). It is manifested by the presence of dark pigmentation staining both granite supports and mural paintings (Marco, 2016 and 2019). The origin of this phenomenon is unknown and may be due to synergy of factors such as microbiological and chemical attacks.info:eu-repo/semantics/publishedVersio

Chitosan coatings reinforced with cellulose crystals and oregano essential oil as antimicrobial protection against the microbiological contamination of stone sculptures

The proliferation of microorganisms in outdoor stone sculptures and cultural objects can damage the structure and aesthetics of the materials through biodeterioration mechanisms. Biocides and synthetic products are often used to prevent this phenomenon, despite their negative impact on the environment and human health. Less toxic alternatives with reduced environmental impact can be an option for the preventive conservation of stone sculptures to reduce the environmental impact. In this work, chitosan formulations reinforced with two types of cellulose crystals (microcrystalline cellulose (MCC) or cellulose nanocrystals (CNCs)) and with or without citric acid and sodium tripolyphosphate were prepared. The films obtained with these formulations showed low solubility, and those only containing MCC or CNCs had the lowest wettability. The formulation containing 2% (w/v) MCC was selected for further analysis and supplemented with oregano essential oil (OEO) at 1% (v/v) and 2% (v/v), exhibiting low solubility, swelling and wettability when polymerised in film form. Inoculation of the films with Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa and Rhodotorula spp. resulted in total or partial inhibition of their growth, as well as a 60–100% reduction in Penicillium chrysogenum growth, depending on the concentration of OEO. The formulation with 2% (v/v) OEO was applied to samples of granite, marble and limestone, forming a protective, yet irregular coating on their surfaces. The wettability of the stones’ surfaces was reduced without becoming completely water-repellent and the coating did not cause visible colour changes.info:eu-repo/semantics/publishedVersio

Characterization of knowledge and consumption of acetylsalicylic acid in users of community pharmacies

Acetylsalicylic acid (ASA) is one of the drugs most used by the Portuguese population for its anti-inflammatory, analgesic, antipyretic and antiplatelet effect. Thus, this study aimed to characterize the knowledge and the consumption pattern of ASA in users of community pharmacies of three locations in the district of Porto. The investigation was achieved by application of a questionnaire to 390 users of community pharmacies of three locations in the district of Porto (Lousada, Paços de Ferreira e Porto). The dosage of ASA most known and consumed was of 500mg (28.2 and 53%, respectively). Individuals considered having a level of knowledge "Reasonable" about this substance (47.8%). As regards the frequency of use, the most reported by respondents was once per year (48.3%), and time-consuming 1 to 3 days (37.8%). A considerable percentage of respondents indicating that ASA was prescribed by the doctor (36.4%) and on his own initiative (36.4%). The main reasons of use of AAS are flu (41.2%), pain head (40%) and fever (10.7%), have been noted adverse effects in 4.1% of consumers. It was found that the level of knowledge is higher in middle age (40-60 years) (p = 0.220) and in individuals with qualifications of 6-9th year. The present study denotes the existence of gaps of consistent, coherent and updated information about ASA drug

From sampling to collection: the sample collection from Universidade Católica Portuguesa

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Assessment of drying conditions of a yeast-based solution for application on textile industrial wastewater treatment plants

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Antimicrobial chitosan/TPP-based coatings for the prevention of biodeterioration of outdoor stone sculptures

Outdoor stone sculptures are prone to accelerated deterioration caused by the proliferation of microorganisms in the stone. The physical, chemical and mechanical action of microorganisms on stone heritage causes aesthetic and structural changes that devalue the artworks over time. Developing more sustainable and ecological alternatives for their preventive conservation is necessary to reduce the negative environmental and human health impacts of currently used toxic biocides. Chitosan-based coatings cross-linked with citric acid and sodium tripolyphosphate (TPP) were developed for application to stone sculptures, as antimicrobial protection to inhibit the growth of degrading microorganisms. After polymerisation of the formulations, the resulting films were only partially soluble while remaining permeable to water vapour. These characteristics offer the possibility to reverse the conservation treatments, or to re-treat in regular periods, as part of programmed conservation strategies. Bacteria and fungi commonly found in stone microbiomes that contribute to biodeterioration processes were inhibited, particularly the pigment-producing yeast Rhodotorula spp., which causes discolouration of stone surfaces. The most interesting coating was successfully tested on granite, limestone and marble samples, and its presence on the stones' surfaces was confirmed by FTIR and SEM analyses. The chitosan-based coating caused no visible colour changes to the stones and reduced the wettability of granite and limestone, thus representing a potential antimicrobial protective layer for stone cultural heritage.info:eu-repo/semantics/publishedVersio