Thermal Versus High Hydrostatic Pressure Treatments on Calcium-added Soybean Proteins : Protein Solubility, Colloidal Stability and Cold-set Gelation

The effects of thermal treatment (TT) and high hydrostatic pressure treatment (HHPT) on calcium-added soybean protein 1% (w/w) aqueous dispersions at pH 7.0 were compared. High hydrostatic pressure, but not thermal treatment, improved protein solubility and colloidal stability. Despite the fact that the glycinin solubility is more affected by calcium than that of β-conglycinin, glycinin could remain in dispersion in the presence of calcium when denatured by HHPT (calcium added before or after treatment), but not when denatured by TT or without denaturing treatment. Thus, polypeptide composition of soluble aggregates depended on type of treatment. Colloidal stability and molecular weight of soluble aggregates depended on the order of application of calcium and denaturing treatment: when calcium was present during either HHPT or TT, the dispersions had higher stability and higher proportion of soluble aggregates with high molecular weight than when calcium was added after treatments. After freeze drying and re-dispersing at higher protein content (10% w/w) calcium-added dispersions subjected to HHPT formed cold-set gels that were transparent and exhibited excellent water holding capacity. Our results provide the basis for the development of ready-to-use functional ingredients.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Herramientas para el monitoreo y sistema de alerta de floraciones de cianobacterias nocivas: Río Uruguay y Río de la Plata = Monitoring tools and early warning system for harmful cyanobacterial blooms: Río Uruguay and Río de la Plata

Las floraciones de cianobacterias potencialmente tóxicas es uno de los problemas más difundidos en los sistemas acuáticos a nivel global. Sin embargo, no existen programas de monitoreo sensibles y directamente aplicables a la predicción de las floraciones y su gestión. Con este objetivo se combinaron conceptos ecológicos y genéticos para generar herramientas para el monitoreo de cianobacterias. Se utilizaron dos aproximaciones: agrupación de organismos en grupos funcionales basados en morfología y análisis moleculares (PCR cuantitativo en tiempo real) que indican presencia de genes que codifican para la expresión de cianotoxinas (mcy). Para evaluar las herramientas se realizaron seis campañas de muestreo bimensuales (2013-2014) en seis estaciones con dos sitios en cada una, a lo largo del Río Uruguay y del Estuario Río de la Plata, desde Salto Grande hasta Punta del Este. Se observó un gradiente marcado en las variables meteorológicas, físico-químicas, y mayores abundancias de organismos planctónicos en Salto Grande y Punta del Este. Se encontró la presencia en todo el gradiente de poblaciones tóxicas, con mayor abundancia en Salto, particularmente del complejo Microcystis aeruginosa (CMA). Las variables ambientales más importantes en determinar el gradiente ambiental y las variaciones en las variables biológicas fueron la salinidad, la temperatura, el viento y la turbidez. Los resultados de los nuevos indicadores (presencia en red del CMA y genes mcy) coincidieron con los tradicionales (ej. clorofila-a) en los casos de floraciones más severas, y ambos fueron sustantivamente más sensibles en situaciones de bajas abundancias. La conjunción de los resultados se aplicó a la construcción de un protocolo de monitoreo y un sistema de alerta

Thermal Versus High Hydrostatic Pressure Treatments on Calcium-added Soybean Proteins : Protein Solubility, Colloidal Stability and Cold-set Gelation

The effects of thermal treatment (TT) and high hydrostatic pressure treatment (HHPT) on calcium-added soybean protein 1% (w/w) aqueous dispersions at pH 7.0 were compared. High hydrostatic pressure, but not thermal treatment, improved protein solubility and colloidal stability. Despite the fact that the glycinin solubility is more affected by calcium than that of β-conglycinin, glycinin could remain in dispersion in the presence of calcium when denatured by HHPT (calcium added before or after treatment), but not when denatured by TT or without denaturing treatment. Thus, polypeptide composition of soluble aggregates depended on type of treatment. Colloidal stability and molecular weight of soluble aggregates depended on the order of application of calcium and denaturing treatment: when calcium was present during either HHPT or TT, the dispersions had higher stability and higher proportion of soluble aggregates with high molecular weight than when calcium was added after treatments. After freeze drying and re-dispersing at higher protein content (10% w/w) calcium-added dispersions subjected to HHPT formed cold-set gels that were transparent and exhibited excellent water holding capacity. Our results provide the basis for the development of ready-to-use functional ingredients.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Thermal Versus High Hydrostatic Pressure Treatments on Calcium-added Soybean Proteins. Protein Solubility, Colloidal Stability and Cold-set Gelation

The effects of thermal treatment (TT) and high hydrostatic pressure treatment (HHPT) on calcium-added soybean protein 1% (w/w) aqueous dispersions at pH 7.0 were compared. High hydrostatic pressure, but not thermal treatment, improved protein solubility and colloidal stability. Despite the fact that the glycinin solubility is more affected by calcium than that of β-conglycinin, glycinin could remain in dispersion in the presence of calcium when denatured by HHPT (calcium added before or after treatment), but not when denatured by TT or without denaturing treatment. Thus, polypeptide composition of soluble aggregates depended on type of treatment. Colloidal stability and molecular weight of soluble aggregates depended on the order of application of calcium anddenaturing treatment: when calcium was present during either HHPTor TT, the dispersions had higher stability and higher proportion of soluble aggregates with high molecularweight thanwhen calcium was added after treatments. After freeze drying and re-dispersing at higher protein content (10% w/w) calcium-added dispersions subjected to HHPT formed cold-set gels that were transparent and exhibited excellent water holding capacity. Our results provide the basis for the development of ready-to-use functional ingredients.Fil: Piccini, Lucía. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Scilingo, Adriana Alicia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Speroni Aguirre, Francisco José. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

A trait-based approach predicting community assembly and dominance of microbial invasive species

Understanding the mechanisms underlying community assembly helps to define success and susceptibility to biological invasions. Here, we explored phytoplankton community assembly following niche and neutral paradigms and using a trait-based approach. Under the hypothesis that the morphology-based functional groups (MBFG) clusters species with similar niche, we analysed how trait-related differences in fitness influence dominance of an invasive species. This was based on literature review, field data and model simulations. We predict that invading species can be dominant if: 1) do not belong to the local MBFG but use unexploited areas of the niche, or 2) belong to the resident MBFG but exhibit a higher fitness due to a particular combination of traits. The invasive dinoflagellate Ceratium furcoides was used as the model species to evaluate these hypotheses, its morphological (e.g. volume) and physiological (e.g. growth rates) traits were compared with species from the same (V: photosynthetic flagellates) and different (VII: colonial cyanobacteria) MBFG. Fitness was estimated using models parametrized with MBFG rates (R*, ability to draw down phosphate) under different environmental conditions (i.e. flushing). Results contributed to support both hypotheses. First, the alternation of C. furcoides and cyanobacteria dominance was explained by the use of different niches. Secondly, species from MBFG V were dominant under similar environments. Within this group V C. furcoides showed higher fitness under low flushing and high predation, advantage provided by a distinctive combination of traits. The application of trait-based approaches to represent the niche and estimate fitness along environmental gradients was useful to evaluate community assembly and can be used to predict the dominance of microbial species invasions.Fil: Kruk, Carla. Universidad de la República; UruguayFil: Piccini, Claudia. Instituto de Investigaciones Biológicas "Clemente Estable"; UruguayFil: Devercelli, Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Nogueira, Lucía. Universidad de la República; UruguayFil: Accattatis, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Sampognaro, Lía. Universidad de la República; UruguayFil: Segura, Angel. Universidad de la República; Urugua

Monitoring tools and early warning system for harmful cyanobacterial blooms: Río Uruguay and Río de la Plata

Potentially hazardous cyanobacterial blooming constitutes one of the most widespread problems experienced by aquatic systems worldwide. However, there are not any monitoring methods sensitive enough to be directly applicable to predict and manage blooming events. In order to fulfill this goal, both ecological and genetic concepts were combined to generate cyanobacteria monitoring tools. Two approaches were used: grouping organisms into functional groups and utilizing molecular analysis (real time quantitative PCR) as indicators of the presence of genes that encode the expression of cyanotoxins (mcy). Six bi-monthly sampling campaigns were performed to evaluate the suitability of these tools (2013-2014) at six locations composed of two sites each one, ranging downstream from Salto Grande, at the River Uruguay, to Punta del Este, at the Estuary River Plate. A remarkable gradient was observed in the meteorological, physical and chemical variables, as well as higher abundances in planktonic organisms both in Salto Grande and in Punta del Este. The most abundant population of toxic species in the whole gradient were found in Salto, and in particular those belonging to the Microcystis aeruginosa complex (MAC). The most relevant environmental variables to determine the gradient and the variation in biological variables were: salinity, temperature, wind and turbidity. The results of the new indicators (presence of MAC in the plankton net and mcy genes) were in agreement with the traditional ones (v.g. chlorophyll-a) demonstrating being much more sensitive in cases of the most severe blooming events than in the low abundance situations. The conjunction of results was applied to the construction of a monitoring and early warning system protocol

Herramientas para el monitoreo y sistema de alerta de floraciones de cianobacterias nocivas: Río Uruguay y Río de la Plata

Potentially hazardous cyanobacterial blooming constitutes one of the most widespread problems experienced by aquatic systems worldwide. However, there are not any monitoring methods sensitive enough to be directly applicable to predict and manage blooming events. In order to fulfill this goal, both ecological and genetic concepts were combined to generate cyanobacteria monitoring tools. Two approaches were used: grouping organisms into functional groups and utilizing molecular analysis (real time quantitative PCR) as indicators of the presence of genes that encode the expression of cyanotoxins (mcy). Six bi-monthly sampling campaigns were performed to evaluate the suitability of these tools (2013-2014) at six locations composed of two sites each one, ranging downstream from Salto Grande, at the River Uruguay, to Punta del Este, at the Estuary River Plate. A remarkable gradient was observed in the meteorological, physical and chemical variables, as well as higher abundances in planktonic organisms both in Salto Grande and in Punta del Este. The most abundant population of toxic species in the whole gradient were found in Salto, and in particular those belonging to the Microcystis aeruginosa complex (MAC). The most relevant environmental variables to determine the gradient and the variation in biological variables were: salinity, temperature, wind and turbidity. The results of the new indicators (presence of MAC in the plankton net and mcy genes) were in agreement with the traditional ones (v.g. chlorophyll-a) demonstrating being much more sensitive in cases of the most severe blooming events than in the low abundance situations. The conjunction of results was applied to the construction of a monitoring and early warning system protocol.Las floraciones de cianobacterias potencialmente tóxicas es uno de los problemas más difundidos en los sistemas acuáticos a nivel global. Sin embargo, no existen programas de monitoreo sensibles y directamente aplicables a la predicción de las floraciones y su gestión. Con este objetivo se combinaron conceptos ecológicos y genéticos para generar herramientas para el monitoreo de cianobacterias. Se utilizaron dos aproximaciones: agrupación de organismos en grupos funcionales basados en morfología y análisis moleculares (PCR cuantitativo en tiempo real) que indican presencia de genes que codifican para la expresión de cianotoxinas (mcy). Para evaluar las herramientas se realizaron seis campañas de muestreo bimensuales (2013-2014) en seis estaciones con dos sitios en cada una, a lo largo del Río Uruguay y del Estuario Río de la Plata, desde Salto Grande hasta Punta del Este. Se observó un gradiente marcado en las variables meteorológicas, físico-químicas, y mayores abundancias de organismos planctónicos en Salto Grande y Punta del Este. Se encontró la presencia en todo el gradiente de poblaciones tóxicas, con mayor abundancia en Salto, particularmente del complejo Microcystis aeruginosa (CMA). Las variables ambientales más importantes en determinar el gradiente ambiental y las variaciones en las variables biológicas fueron la salinidad, la temperatura, el viento y la turbidez. Los resultados de los nuevos indicadores (presencia en red del CMA y genes mcy) coincidieron con los tradicionales (ej. clorofila-a) en los casos de floraciones más severas, y ambos fueron sustantivamente más sensibles en situaciones de bajas abundancias. La conjunción de los resultados se aplicó a la construcción de un protocolo de monitoreo y un sistema de alerta