Solubilization and characterization of a cell wall-bound trehalase from ascospores of the fission yeast Schizosaccharomyces pombe

©. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published Manuscript version of a Published Work that appeared in final form in [Microbiological Research]. To access the final edited and published work see [https://doi.org/10.1016/j.micres.2006.12.005]The genome of the fission yeast Schizosaccharomyces pombe lacks sequence homologs to ath1 genes coding for acid trehalases in other yeasts or filamentous fungi. However, acid trehalase activity is present at the spore stage in the life cycle of the fission yeast. The enzyme responsible for this activity behaves as a surface enzyme covalently linked to the spore cell walls in both wild-type and ntp1 mutant strains devoid of neutral trehalase. Lytic treatment of particulated cell wall fractions allowed the solubilization of the enzyme into an active form. We have characterized this soluble enzyme and found that its kinetic parameters, optimum pH and temperature, thermal denaturation and salt responses are closely similar to other conventional acid trehalases. Hence, this rather unusual enzyme can be recognized as acid trehalase by its biochemical properties although it does not share genetic homology with other known acid trehalases. The potential role of such acid trehalase in the mobilization of trehalose is discussed

Transduction of centrifugation-induced gravity forces through mitogen-activated protein kinase pathways in the fission yeast Schizosaccharomyces pombe

©. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published Manuscript version of a Published Work that appeared in final form in [Microbiology]. To access the final edited and published work see [https://doi.org/10.1099/mic.0.2006/004283-0]Centrifugation of cells of Schizosaccharomyces pombe in liquid medium prompted a marked activation of Sty1 and Pmk1, which are the effector mitogen-activated protein kinases (MAPKs) of the stress-activated protein kinase pathway and the cell-integrity pathway, respectively. Transduction of the centrifugation signals showed a sensitivity threshold above which the response was dependent on time and temperature. Centrifugation-induced phosphorylation of Sty1 and Pmk1 required the presence of the main functional components of the respective signalling cascades, i.e. Wak1 or Win1 plus Wis1, and Mkh1 plus Pek1. The transcription factor Atf1 also became phosphorylated in a Sty1-dependent way upon centrifugation. Hypergravity was an important factor in the activation of Sty1 induced by centrifugation, whilst activation of Pmk1 was mostly due to gravity-associated shear forces. Centrifugation did not increase cell survival against other stresses. Rather, the increased gravitational forces produced a delay in the cell cycle, probably related to alterations in the actin-polarization pattern. Phosphorylation of the MAPK Sty1 was needed for the depolarization of actin patches induced by the centrifugation stress

Evaluation of biocides in oilfield environments using fluorescent <i>in-situ</i> hybridization

Microbiologically influenced corrosion and souring of oilfield reservoirs are process frequently provoked by the sulphate-reducing bacteria. The most common method applied in the industry for preventing or controlling the deleterious effect caused by the presence of microorganisms is the addition of chemical agents (biocides) aimed at killing the microorganisms or inhibiting the microbial growth. Traditionally, biocide selection and testing are based on NACE standard TM0194 which implies the use of culturing for enumerating the bacteria surviving the treatment. To overcome culturing limitations, we used Fluorescent in-situ Hybridization to assist in the evaluation of biocides applied in water production treatment plants. Biocides were based on THPS (40% (B1); 75% (B2)) and 40% of a mixture (1/1, v/v) of THPS and benzalkonium chloride (B3) applied at two concentrations: 50 and 400 mg/L. The relation between the number of cells visualized with the fluorescent probes Eub338 and SRB385 (for eubacteria and SRB populations respectively) and the DAPI-stained cells (PR%) was used as an indication of the biocide efficiency. B1 and B3 gave a high PR% indicating that the chemical induced the metabolic cell activity. Only the highest B2 concentration showed effectiveness on eubacteria and SRB populations. Thus, through the application of FISH we were able to distinguish concentration effects of the THPS, discriminating sublethal from net inhibitory effects. The possibility of including FISH into the protocols for the control of the biocides in water treatment plants could improve the biocide selection and the adjustment of their concentration in order to maintain the water system with a low density of metabolically active cells. This would avoid the misuse of chemicals with their consequent economic and ecological impacts.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesCentro de Investigación y Desarrollo en Tecnología de Pintura

Evaluation of biocides in oilfield environments using fluorescent <i>in-situ</i> hybridization

Microbiologically influenced corrosion and souring of oilfield reservoirs are process frequently provoked by the sulphate-reducing bacteria. The most common method applied in the industry for preventing or controlling the deleterious effect caused by the presence of microorganisms is the addition of chemical agents (biocides) aimed at killing the microorganisms or inhibiting the microbial growth. Traditionally, biocide selection and testing are based on NACE standard TM0194 which implies the use of culturing for enumerating the bacteria surviving the treatment. To overcome culturing limitations, we used Fluorescent in-situ Hybridization to assist in the evaluation of biocides applied in water production treatment plants. Biocides were based on THPS (40% (B1); 75% (B2)) and 40% of a mixture (1/1, v/v) of THPS and benzalkonium chloride (B3) applied at two concentrations: 50 and 400 mg/L. The relation between the number of cells visualized with the fluorescent probes Eub338 and SRB385 (for eubacteria and SRB populations respectively) and the DAPI-stained cells (PR%) was used as an indication of the biocide efficiency. B1 and B3 gave a high PR% indicating that the chemical induced the metabolic cell activity. Only the highest B2 concentration showed effectiveness on eubacteria and SRB populations. Thus, through the application of FISH we were able to distinguish concentration effects of the THPS, discriminating sublethal from net inhibitory effects. The possibility of including FISH into the protocols for the control of the biocides in water treatment plants could improve the biocide selection and the adjustment of their concentration in order to maintain the water system with a low density of metabolically active cells. This would avoid the misuse of chemicals with their consequent economic and ecological impacts.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesCentro de Investigación y Desarrollo en Tecnología de Pintura

Light-induced rhythmic changes in thermotolerance in stationary-phase cells of Candida utilis

The original publication is available on LINK at In synchronized light-dark cycles, stationary-phase cultures of the budding yeast Candida utilis were able to survive heat treatment at 50ºC with an apparent circadian-like rhythm related to the onset of light. However, in continuous darkness this pattern did not run freely and was markedly dampened. We discuss these findings in terms of the potential circadian control of heat tolerance, which has been described in the fission yeast Schizosaccharomyces pombe. Our results suggest that the resistance pattern observed in C. utilis is most likely an adaptive response to the light-induced generation of reactive oxygen species rather than the occurrence of a truly endogenous circadian rhythmLa supervivencia de cultivos de Candida utilisen la fase estacionaria tras ser sometidos a temperaturas de 50ºC en ciclos sincronizados de luz/oscuridad presentó un aparente ritmo circadiano relacionado con el inicio de la fase iluminada. Sin embargo, en condiciones de oscuridad continua este patrón no se observaba tan claramente y mostraba una marcada ambigüedad. Estas observaciones se discuten en términos de un posible control circadiano de la tolerancia a altas temperaturas, que ha sido descrito para la levadura Schizosaccharomyces pombe. Nuestros resultados indican que el patrón de resistencia observado en C. utilises muy probablemente una respuesta adaptativa a la generación de especies reactivas de oxígeno inducida por luz y que no existe un verdadero ritmo circadiano endógeno.Asobrevivência de cultivos de Candida utilis na fase estacionária depois de ser submetidos a temperaturas de 50ºC em ciclos sincronizados de luz/escuridão apresentou um aparente ritmo circadiano relacionado com o início da fase iluminada. No entanto, em condições de escuridão contínua este patrão não foi observado tão claramente e mostrou uma marcada ambigüidade. Estas observações são discutidas com relação a um possível controle circadiano da tolerância a altas temperaturas, que foi descrito para a levedura Schizosaccharomyces pombe. Nossos resultados indicam que o patrão de resistência observado em C. utilisé muito provavelmente uma resposta adaptativa à geração de espécies reativas de oxigênio induzida por luz e que não existe um verdadeiro ritmo circadiano endógeno

Light-induced rhythmic changes in thermotolerance in stationary-phase cells of Candida utilis

In synchronized light-dark cycles, stationary-phase cultures of the budding yeast Candida utilis were able to survive heat treatment at 50ºC with an apparent circadian-like rhythm related to the onset of light. However, in continuous darkness this pattern did not run freely and was markedly dampened. We discuss these findings in terms of the potential circadian control of heat tolerance, which has been described in the fission yeast Schizosaccharomyces pombe. Our results suggest that the resistance pattern observed in C. utilis is most likely an adaptive response to the light-induced generation of reactive oxygen species rather than the occurrence of a truly endogenous circadian rhythm. [Int Microbiol 2006; 9(1):61-64

Organizations should know their people: a behavioral economics approach

Public and private organizations are increasingly applying behavioral economics methods to a variety of issues such as mechanism design and incentive architecture. However, there has been little focus on how experimental tools used in behavioral economics can help companies learn more about their (current or prospective) workforce and, more specifically, about their employees’ tastes and inclinations. This has important implications for broader organizational performance since some designs/incentives are likely to affect only individuals with a particular disposition (e.g. risk averse or fairness oriented) but not others, or can even have opposite effects on individuals with different sets of preferences. In this commentary, we point out a number of promising avenues for the application of a behavioral economics lens to understand and manage people within organizations. A comprehensive case study is also provided

Bebidas funcionales de arándanos con agregado de Goma Arábiga

Introduction: This study aimed to add value to Arabic Gum (AG) and the blueberry discarded harvest from Northwest of Argentina, developing functional dietary beverages with AG at three concentrations of 0; 5; 10 and 15 g/100 mL, and to assess the sensory acceptability, physicochemical characteristics and antioxidant properties. Material and methods: Blueberries (BB) at 30 g/100 mL and steviol glycosides (0.03 g/100 mL) were used. Results: The beverage with 10 g/100 mL of AG had the best scores for sensory acceptability and was preferred by consumers. It has a pH of 3.88, soluble solid content of 14.97 °Brix, density of 1.05 g/cm3 and a colour which showed a tendency from red to blue. The Total Caloric Value (per 100 mL of beverage) was 53.4 Kcal, 13.53 g of carbohydrates, 8.80 g of total dietary fibre, and a sodium content of 12.26 mg. The total polyphenol content was 214.23 mg GAE /100 g. Conclusions: The serving size of functional beverage covers 70% of the daily dietary fibre recommendation.  Introducción: Este estudio tuvo como objetivo agregar valor a la goma arábiga (AG) y la cosecha de arándanos descartados del noroeste de Argentina, desarrollando bebidas dietéticas funcionales con AG en tres concentraciones de 0; 5; 10 y 15 g / 100 mL, y evaluar la aceptabilidad sensorial, las características fisicoquímicas y las propiedades antioxidantes. Material y métodos: Se utilizaron arándanos (BB) a 30 g / 100 mL y glucósidos de esteviol (0,03 g / 100 mL). Resultados: La bebida con 10 g / 100 mL de AG tuvo las mejores puntuaciones de aceptabilidad sensorial y fue la preferida por los consumidores. Tiene un pH de 3,88, contenido de sólidos solubles de 14,97 ° Brix, densidad de 1,05 g / cm3 y un color que mostró una tendencia del rojo al azul. El Valor Calórico Total (por 100 mL de bebida) fue de 53,4 Kcal, 13,53 g de carbohidratos, 8,80 g de fibra dietética total y un contenido de sodio de 12,26 mg. El contenido total de polifenoles fue de 214,23 mg GAE / 100 g. Resultados: Una porción de bebida funcional cubre el 70% de la recomendación diaria de fibra dietética

Adelante / Endavant

Séptimo desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere "Purificación Escribano" de la Universitat Jaume

A conserved non-canonical docking mechanism regulates the binding of dual specificity phosphatases to cell integrity mitogen-activated protein kinases (MAPKs) in budding and fission yeasts.

Dual-specificity MAPK phosphatases (MKPs) are essential for the negative regulation of MAPK pathways. Similar to other MAPK-interacting proteins, most MKPs bind MAPKs through specific docking domains known as D-motifs. However, we found that the Saccharomyces cerevisiae MKP Msg5 binds the MAPK Slt2 within the cell wall integrity (CWI) pathway through a distinct motif (IYT). Here, we demonstrate that the IYT motif mediates binding of the Msg5 paralogue Sdp1 to Slt2 as well as of the MKP Pmp1 to its CWI MAPK counterpart Pmk1 in the evolutionarily distant yeast Schizosaccharomyces pombe. As a consequence, removal of the IYT site in Msg5, Sdp1 and Pmp1 reduces MAPK trapping caused by the overexpression of catalytically inactive versions of these phosphatases. Accordingly, an intact IYT site is necessary for inactive Sdp1 to prevent nuclear accumulation of Slt2. We also show that both Ile and Tyr but not Thr are essential for the functionality of the IYT motif. These results provide mechanistic insight into MKP-MAPK interplay and stress the relevance of this conserved non-canonical docking site in the regulation of the CWI pathway in fungi