Biosynthesized silver nanoparticles to control fungal infections in indoor environments

Fungi grow especially in dark and moist areas, deteriorating the indoor environment and causing infections that particularly affect immunosuppressed individuals. Antimicrobial coatings have as principal objective to prevent biofilm formation and infections by incorporation of bioactive additives. In this sense, metallic nanoparticles, such as silver, have proven to be active against different microorganisms specially bacteria. Biosynthesized method is a promising environmentally friendly option to obtain nanoparticles. The aim of this research was assess the employment of plants extracts of Aloysia triphylla (cedrón), Laurelia sempervirens (laurel) and Ruta chalepensis (ruda) to obtain silver nanoparticles to be used as an antimicrobial additive to a waterborne coating formulation. The products obtained were assessed against fungal isolates from biodeteriorated indoor coatings. The fungi were identified by conventional and molecular techniques as Chaetomium globosum and Alternaria alternate. The results revealed that the coating with silver nanoparticles obtained with L. sempervirens extract at 60°C with a size of 9.8 nm was the most efficient against fungal biofilm development.Fil: Deya, Marta Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentin

Biosynthesized silver nanoparticles to control fungal infections in indoor environments

Fungi grow especially in dark and moist areas, deteriorating the indoor environment and causing infections that particularly affect immunosuppressed individuals. Antimicrobial coatings have as principal objective to prevent biofilm formation and infections by incorporation of bioactive additives. In this sense, metallic nanoparticles, such as silver, have proven to be active against different microorganisms specially bacteria. Biosynthesized method is a promising environmentally friendly option to obtain nanoparticles. The aim of this research was assess the employment of plants extracts of Aloysia triphylla (cedrón), Laurelia sempervirens (laurel) and Ruta chalepensis (ruda) to obtain silver nanoparticles to be used as an antimicrobial additive to a waterborne coating formulation. The products obtained were assessed against fungal isolates from biodeteriorated indoor coatings. The fungi were identified by conventional and molecular techniques as Chaetomium globosum and Alternaria alternate. The results revealed that the coating with silver nanoparticles obtained with L. sempervirens extract at 60 °C with a size of 9.8 nm was the most efficient against fungal biofilm development.Centro de Investigación y Desarrollo en Tecnología de Pinturas (CIDEPINT

Mycological studies as a tool to improve the control of building materials biodeterioration

Fungal deterioration of building materials causes economic losses due to restoration processes and because it affects the health of the people exposed. Therefore, it is necessary to obtain highly deteriorating fungal strains to carry out studies focused on biodeterioration control. The aim of this research was to study the mycobiota involved in deterioration of facades through the isolation and characterization of fungal strains. In this sense, this paper characterizes the mycobiota that contributes to the deterioration of brick and concrete present in those places. Samples were taken from bricks and concrete with visible biodeterioration of the Cathedral of La Plata and the Experimental Station of the Centro de Investigación y Desarrollo en Tecnología de Pinturas. Relative density, apparition relative frequency, and ecological category of fungi isolates were determined. The deteriorating attributes were determined by carbonate dissolution test, pigment secretion assay, acid production test and brick weight variation. Cladosporium sp., Penicillium sp. and Aspergillus sp. were the taxa with the highest apparition relative frequency and abundance. Aspergillus niger MN371276, Lasiodiplodia theobromae MN371283, Cladosporium sphaerospermum MN371394, Penicillium commune MN371392 and Arthothelium spectabile MT071822 were the strains with the highest biodeteriorant activity. These strains can be used in studies on biodeterioration control of buildings materials.Centro de Investigación y Desarrollo en Tecnología de PinturasInstituto de Botánica "Dr. Carlos Spegazzini

Mycological studies as a tool to improve the control of building materials biodeterioration

Fungal deterioration of building materials causes economic losses due to restoration processes and because it affects the health of the people exposed. Therefore, it is necessary to obtain highly deteriorating fungal strains to carry out studies focused on biodeterioration control. The aim of this research was to study the mycobiota involved in deterioration of facades through the isolation and characterization of fungal strains. In this sense, this paper characterizes the mycobiota that contributes to the deterioration of brick and concrete present in those places. Samples were taken from bricks and concrete with visible biodeterioration of the Cathedral of La Plata and the Experimental Station of the Centro de Investigación y Desarrollo en Tecnología de Pinturas. Relative density, apparition relative frequency, and ecological category of fungi isolates were determined. The deteriorating attributes were determined by carbonate dissolution test, pigment secretion assay, acid production test and brick weight variation. Cladosporium sp., Penicillium sp. and Aspergillus sp. were the taxa with the highest apparition relative frequency and abundance. Aspergillus niger MN371276, Lasiodiplodia theobromae MN371283, Cladosporium sphaerospermum MN371394, Penicillium commune MN371392 and Arthothelium spectabile MT071822 were the strains with the highest biodeteriorant activity. These strains can be used in studies on biodeterioration control of buildings materials.Fil: Gámez Espinosa, Erasmo Junior. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Deya, Marta Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Cabello, Marta Noemí. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Botánica Spegazzini; Argentin

Attributes of nanoparticles obtained by green synthesis for application in antifungal coatings

The green synthesis of nanoparticles based on the use of aqueous vegetable extracts islow cost, non-polluting and makes use of renewable reagents. These extracts containmetabolites that perform as reducing and stabilizing agents. In this regard, the use oftannins is promising due to their high polyphenol content. The present work proposes tosynthesize and characterize nanoparticles obtained silver and copper salts with ?tara?tannin (TT). TT is commercially available and proceeds aqueous extract of Caesalpiniaspinosa. The nanoparticles were obtained starting an aqueous solution of AgNO3 10-2 Mand Cu(NO3)2.3H2O 10-2 M to which the tannin solution was added in constantagitation. Three concentrations of TT were used: 500, 1000 and 2000 ppm. This processwas done at 60° C and pH = 7. The stability over time of these nanoparticles wasevaluated by UV-vis spectroscopy carried out at different times: 1, 30 and 60 days. Toconfirm the obtaining of the nanoparticles and observe their morphology, transmissionelectron microscopy (TEM) was applied. The synthesized nanoparticles were purified andFourier transform infrared spectroscopy (FTIR) was performed. The antifungal activity wasevaluated by the agar diffusion test (Kirby-Bauer) against the collection strains: Cladosporiumcladosporioides (MG731215), Alternaria tunuissima (MG731240) and Aspergillus versicolor (MG725821).UV-vis spectra of silver nanoparticles obtained TT solutions of 500 (NpsAg500), 1000 (NpsAg1000) and2000ppm (NpsAg2000) presented an absorption maximum around 400, 410 and 420 nm, respectively.These bands remained stable over time. In the case of copper salt the nanoparticles obtained with TTsolution of 2000ppm (NpsCu2000) showed a band at 330 nm and with 1000 and 500ppm resultedunstable. TEM micrographs confirmed the presence of quasispherical nanoparticles predominantlysmaller than 20 nm with higher frequency. FTIR spectra confirmed the strong interaction between ofthe nanoparticles and the tannin used in the synthesis. Related to the agar diffusion test, NpsCu2000was not active against the fungal strains used while the silver nanoparticles showed to be active inall cases. In this sense, NpsAg500 presented the highest inhibition zone against C. cladosporioides. Thenext step will be to formulate coatings with these nanoparticles.Fil: Gámez Espinosa, Erasmo Junior. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Deya, Marta Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaXXVII International Materials Research Congress - IMRC 2018CancúnMéxicoSociedad Mexicana de Materiale

Fungal deterioration control in outdoor environments by nano-additivated waterborne paint

Biodeterioration of facades in building constructions causes economic damage. Filamentous fungi by their presence cause aesthetic damage to structural materials. In addition, its invasive growth through hyphae generates physical deterioration and due to its nutrition and excretion, they release enzymes, acids and pigments that cause chemical deterioration.To control fungal deterioration, paint additives with nanostructured biocides can be applied on facades.In addition, it is important that the nanoadditive maintains its long-term antimicrobial activity to delay fungal deterioration.The aim of this research was to assess the antifungal activity of a waterborne paint additivated with ZnO nanoparticles (ZnONPs) after 4 years exposed to the outdoor environment.Fil: Gámez Espinosa, Erasmo Junior. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Deya, Marta Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaXXV Congreso Latinoamericano de Microbiología; V Congreso Paraguayo de Microbiología; IX Congreso Nacional de Bioquímica Clínica y I Congreso Paraguayo de Bioquímica y Ciencias del LaboratorioAsunciónParaguayAsociación Latinoamericana de Microbiologí

Biosynthesized silver nanoparticles to control fungal infections in indoor environments

Fungi grow especially in dark and moist areas, deteriorating the indoor environment and causing infections that particularly affect immunosuppressed individuals. Antimicrobial coatings have as principal objective to prevent biofilm formation and infections by incorporation of bioactive additives. In this sense, metallic nanoparticles, such as silver, have proven to be active against different microorganisms specially bacteria. Biosynthesized method is a promising environmentally friendly option to obtain nanoparticles. The aim of this research was assess the employment of plants extracts of Aloysia triphylla (cedrón), Laurelia sempervirens (laurel) and Ruta chalepensis (ruda) to obtain silver nanoparticles to be used as an antimicrobial additive to a waterborne coating formulation. The products obtained were assessed against fungal isolates from biodeteriorated indoor coatings. The fungi were identified by conventional and molecular techniques as Chaetomium globosum and Alternaria alternate. The results revealed that the coating with silver nanoparticles obtained with L. sempervirens extract at 60 °C with a size of 9.8 nm was the most efficient against fungal biofilm development.Centro de Investigación y Desarrollo en Tecnología de Pinturas (CIDEPINT

Natural products to control biofilm on painted surfaces

Purpose – This paper aims to study five vegetables extracts as possible additives to control bacterial growth on indoor waterborne paints. The extracts were obtained from the weeds Raphanus sativus, Rapistrum rugosum, Sinapis arvensis, Nicotiana longiflora and Dipsacus fullonum, used in traditional medicine as antimicrobial compounds. Design/methodology/approach – Weeds extracts were characterized by Fourier transform infrared spectroscopy and UV–Vis spectrophotometry. Their antibacterial activity against Escherichia coli and Staphylococcus aureus was also determined. Afterward, selected extracts were incorporated in waterborne paint formulations. The paints’ antimicrobial activity was assessed against S. aureus, monitoring biofilm formation by environmental scanning electron microscopy. Findings – As a general rule, results showed that tested paints were efficient in inhibiting biofilm formation, especially that formulated with Nicotiana longiflora. Practical implications – The tested paints can be used to protect walls from microbial colonization, which shortened coatings’ useful life by discoloration and/or degradation. Concomitantly, indoor microbial colonization by aerosols could be also diminished. This is especially important in places that should have high standards of environmental hygiene, as in the food industry, health-care and sanitary centers. Originality/value – The main value of this research was to study the antimicrobial activity of weeds extracts and to incorporate them in waterborne paints to diminish bacterial biofilm formation. This biofilm discolors and degrades the paint, and causes health problems. The use of natural compounds in coatings is increasing because of the convenience of using renewable sources, such as natural antimicrobials, in paint formulations.Centro de Investigación y Desarrollo en Tecnología de Pinturas (CIDEPINT)Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA

Antifouling Paints with Zinc “Tannate”

During the past decade, the necessity of new ecofriendly antifouling pigments was established. Among these new pigments, special attention should be paid to tannin and its derivatives. Tannins are synthesized by plants as part of their defense mechanism against the attack of pathogens. The objective of this work was to study the antifouling efficiency of paints containing zinc “tannate” in artificial seawater. The zinc “tannate” was precipitated at pH 4 and pH 8. Insoluble and soluble matrix antifouling paints, with different plasticizers, were formulated and tannins leached from the paints immersed in artificial seawater were determined by the Folin-Denis assay for polyphenols. The antifouling action of paints was assessed in a natural seawater environment. The results showed that the leaching rate of tannin from insoluble matrix paint decreases, reaching a constant value after 25 days of immersion. In the case of the soluble matrix paints, a lesser amount of tannin was leached, depending on the tannin and the plasticizer employed. The results in a natural sea environment are dependent on the matrix and the plasticizer employed.Centro de Investigación y Desarrollo en Tecnología de Pintura