A Novel Method for the Quantification of White Wine Mannoproteins by a Competitive Indirect Enzyme-Linked Lectin Sorbent Assay (CI-ELLSA)

Mannoproteins (MPs) are cell wall proteoglycans released in wine by yeast during fermentation and ageing on lees, a procedure used for the production of several wines to enrich them in these components with consequences from both a technological and sensory point of view. Given the significance that wine MPs have for wine quality, winemakers would welcome a simple and accurate method for their quantification, as this would allow them to have a better control of this aspect at different winemaking stages. This study develops and validates a novel, simple and accurate method for MPs quantification in white wines based on a competitive indirect enzyme-linked lectin sorbent assay (CI-ELLSA), using the highly mannosylated yeast invertase as the standard. The method utilizes the lectin concanavalin A (ConA) as the immobilized ligand for MPs, and peroxidase, an enzyme rich in mannose, as the competitor for ConA. After addition of the peroxidase substrate, the intensity of the signal produced by the activity of this enzyme (absorbance at 450 nm) is inversely proportional to the amount of mannosylated proteins in the sample. Results have been validated on several wine styles including still, sparkling and sweet wines

Characterization of esterase activity in the Bianchetta trevigiana grape variety under reducing conditions

Giovanna Lomolino, Anna LanteDepartment of Agronomy Food Natural Resources Animals and Environment, Agripolis, Università di Padova Viale dell'Università, Padova, ItalyBackground and methods: While extensive research has been carried out on the enzymes responsible for ester synthesis and hydrolysis by wine strains of Saccharomyces cerevisiae, grape esterase activity is limited. In this study, the autochthonous grape variety, Bianchetta trevigiana, widespread in the Prosecco wine production area of Treviso, Conegliano, and Asolo, Italy, was characterized according to its esterase activity. Because grape skin is very rich in compounds which impart qualitative characteristics to wine, the study of esterase was carried out on this part of the fruit.Results: During enzyme extraction from grape skin, the presence of the reducing agent, β-mercaptoethanol, allowed a better protein yield but reduced esterase activity. Further addition of increasing doses of reducing agents to grape skin protein extract, such as of K2S2O5 (used in winemaking) and DTT, reduced or inhibited esterase activity. Even though the zymographic profiles of the extracts obtained with and without β-mercaptoethanol were qualitatively equal, the intensity of enzymatic bands, measured by densitometry, was different.Conclusion: The presence of reducing agents affected the activity of grape skin esterase, and given that this enzyme is involved in the hydrolysis and synthesis of esters, which are important compounds responsible for the flavor of wine, addition of reducing agents could affect the aromatic profile of wine.Keywords: esterase, grape, reducing agent, win

Kvantitativno određivanje lipaze pomoću fluoresceina

An easy and fast gel diffusion assay for detecting and monitoring lipase activity by quantification of fluorescein is described. By measuring the intensity of fluorescein, it is possible to obtain a calibration curve with a regression coefficient better than by using the radius of fluorescent haloes. Through the quantification of fluorescence intensity of fluorescein released after the hydrolysis of a fluorescent ester, fluorescein dibutyrate, used as substrate in agar plates, commercial and skimmed milk lipase activity were studied. Moreover, with this method, lipase activity can be monitored in reaction medium that contains compounds which are affected by turbidity or cause measurement interference for UV-spectrophotometer and fluorimeter. In this experiment, boiled skimmed milk was dispersed in the agar gel with fluorescein dibutyrate, and it was used as a reaction medium to mimic natural conditions. The development of such an assay has a potential for applications in industries ranging from pharmaceuticals to food production and monitoring.U radu je opisana jednostavna i brza metoda određivanja i praćenja aktivnosti lipaze pomoću fluoresceina. Mjerenjem intenziteta fluorescencije fluoresceina može se dobiti kalibracijska krivulja s koeficijentom regresije boljim od onog dobivenog mjerenjem promjera fluorescentne zone. Kvantitativnim određivanjem intenziteta fluorescencije fluoresceina, oslobođenog hidrolizom estera fluorescein dibutirata na podlozi s agarom, ispitana je aktivnost komercijalne lipaze, te one izolirane iz obranog mlijeka. Ovom se metodom može pratiti aktivnost lipaze u reakcijskoj smjesi koja sadržava spojeve što uzrokuju zamućenje ili interferiraju s uzorkom pri mjerenju UV-spektrofotometrom i fluorimetrom. U istraživanju je upotrijebljena reakcijska smjesa od prokuhanog obranog mlijeka raspršenog na agar gelu s fluorescein dibutiratom. Daljnim bi se razvojem ova metoda mogla primijeniti u farmaceutskoj i prehrambenoj industriji, zaštiti okoliša i sl

Current and future strategies for wine yeast lees valorization

Wine lees is a sludge material mainly composed of dead yeast precipitated at the bottom of wine tanks. Along with grape pomace and grape stalks, it is one of the main by-products of the winemaking industry. Given that wine lees are considered a soil pollutant, their disposal represents a cost for wineries. Numerous wine lees recovery and valorization strategies have been proposed, with a particularly steep increase in published research in recent years. This attention is strictly linked to the concepts of circular economy and environmental sustainability that are attracting the interest of the scientific community. In this review, an overview on the available wine lees recovery and valorization strategies is reported. Additionally, the methods for the extraction and valorization of yeast's cell wall polysaccharides (\u3b2-glucans and mannoproteins) are discussed. Finally, current and future innovative applications in different sectors of yeast \u3b2-glucans and mannoproteins are described and critically discussed

Modeling two-language competition dynamics

During the last decade, much attention has been paid to language competition in the complex systems community, that is, how the fractions of speakers of several competing languages evolve in time. In this paper we review recent advances in this direction and focus on three aspects. First we consider the shift from two-state models to three state models that include the possibility of bilingual individuals. The understanding of the role played by bilingualism is essential in sociolinguistics. In particular, the question addressed is whether bilingualism facilitates the coexistence of languages. Second, we will analyze the effect of social interaction networks and physical barriers. Finally, we will show how to analyze the issue of bilingualism from a game theoretical perspective.Comment: 15 pages, 5 figures; published in the Special Issue of Advances in Complex Systems "Language Dynamics

Plano de Recuperação de Área Degradada: Restauração da área do antigo lixão do município de Estrela do Sul-MG

Trabalho de Conclusão de Curso (Graduação)A recuperação de áreas degradadas é um importante instrumento para a melhora da qualidade de vida da sociedade e uma tentativa de reestabelecimento do equilíbrio ambiental. Quando realizado de forma responsável traz resultados em curto e longo prazo. O Brasil também vem se desenvolvendo de forma eficaz no que diz respeito à qualidade ambiental, onde um avanço importante foi a aprovação da Lei Federal 12.305, de 02 de agosto de 2010, que regulamenta o Plano Nacional de Resíduos Sólidos, proibindo a criação dos “lixões” e decretando o fechamento dos que estão em funcionamento. A lei prevê também o recolhimento adequado os resíduos por meio da coleta seletiva, ecopontos, criação de associação de catadores entre outras, que beneficiam a sociedade e o meio ambiente. A aprovação desta lei é fundamental para a conscientização de uma sociedade pautada no consumo como o Brasil. Com a Lei 12.305, os municípios vêm se adequando para cumprir esta norma legal. Visando a aplicação desta Lei Federal o município de Estrela do Sul, juntamente com outros 8 (oito) municípios integrantes do Consórcio Região de Desenvolvimento Sustentável – RIDES, assinou um Termo de Ajustamento de Conduta (TAC) no dia 04/04/2016 com o Ministério Público Estadual. Este TAC tem como objeto a regularização da destinação final adequada dos resíduos sólidos no município, adequação do aterro às normas ambientais pertinentes, bem como a recuperação das áreas degradadas pelo lixão do municipal. A obrigatoriedade do PRAD dos lixões consta nas Cláusulas 16 e 17 e nos respectivos parágrafos do TAC. O foco deste Trabalho de Conclusão de Curso é elaboração do Plano de Recuperação de Área Degradada (PRAD) no município de Estrela do Sul, obedecendo a ações previstas na Lei 12.305 de agosto de 2010, cláusulas 16 e 17 e nos respectivos parágrafos do TAC. Apresentando uma proposta de adequação ambiental para a área

Influence of geography on language competition

Competition between languages or cultural traits diffusing in the same geographical area is studied combining the language competition model of Abrams and Strogatz and a human dispersal model on an inhomogeneous substrate. Also, the effect of population growth is discussed. It is shown through numerical experiments that the final configuration of the surviving language can be strongly affected by geographical and historical factors. These factors are not related to the dynamics of culture transmission, but rather to initial population distributions as well as geographical boundaries and inhomogeneities, which modulate the diffusion process.Comment: typos in contact information have been corrected - text/figures not change