Isolation of a yeast strain able to produce a polygalacturonase with maceration activity of cassava roots

The objective of the present study was the isolation of a yeast strain, from citrus fruit peels, able to produce a polygalacturonase by submerged fermentation with maceration activity of raw cassava roots. Among 160 yeast strains isolated from citrus peels, one strain exhibited the strongest pectinolytic activity. This yeast was identified as Wickerhamomyces anomalus by 5.8S-ITS RFLP analysis and confirmed by amplification of the nucleotide sequence. The yeast produced a polygalacturonase (PG) in Erlenmeyer shake flasks containing YNB, glucose, and citrus pectin. PG synthesis occurred during exponential growth phase, reaching 51 UE.mL-1 after 8 hours of fermentation. A growth yield (Yx/s) of 0.43 gram of cell dry weight per gram of glucose consumed was obtained, and a maximal specific growth rate (μm) of 0.346 h-1 was calculated. The microorganism was unable to assimilate sucrose, galacturonic acid, polygalacturonic acid, or citrus pectin, but it required glucose as carbon and energy source and polygalacturonic acid or citrus pectin as inducers of enzyme synthesis. The crude enzymatic extract of Wickerhamomyces anomalus showed macerating activity of raw cassava. This property is very important in the production of dehydrated mashed cassava, a product of regional interest in the province of Misiones, Argentina.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Isolation of a yeast strain able to produce a polygalacturonase with maceration activity of cassava roots

The objective of the present study was the isolation of a yeast strain, from citrus fruit peels, able to produce a polygalacturonase by submerged fermentation with maceration activity of raw cassava roots. Among 160 yeast strains isolated from citrus peels, one strain exhibited the strongest pectinolytic activity. This yeast was identified as Wickerhamomyces anomalus by 5.8S-ITS RFLP analysis and confirmed by amplification of the nucleotide sequence. The yeast produced a polygalacturonase (PG) in Erlenmeyer shake flasks containing YNB, glucose, and citrus pectin. PG synthesis occurred during exponential growth phase, reaching 51 UE.mL-1 after 8 hours of fermentation. A growth yield (Yx/s) of 0.43 gram of cell dry weight per gram of glucose consumed was obtained, and a maximal specific growth rate (μm) of 0.346 h-1 was calculated. The microorganism was unable to assimilate sucrose, galacturonic acid, polygalacturonic acid, or citrus pectin, but it required glucose as carbon and energy source and polygalacturonic acid or citrus pectin as inducers of enzyme synthesis. The crude enzymatic extract of Wickerhamomyces anomalus showed macerating activity of raw cassava. This property is very important in the production of dehydrated mashed cassava, a product of regional interest in the province of Misiones, Argentina.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Extracción de pectina a partir de albedo de limón con una Poligalacturonasa de Wickerhamomyces Anomalus

El objetivo del presente trabajo fue evaluar el efecto de diferentes factores en la extracción de pectina a partir de albedo de limón, mediante el extracto enzimático con actividad poligalacturonasa de Wickerhamomyces anomalus (WA cepa 110), una levadura autóctona de la provincia de Misiones, Argentina. El proceso de extracción enzimática de pectina se realizó en frascos Erlenmeyers conteniendo albedo de limón, buffer y el extracto enzimático crudo de WA cepa 110, con agitación (pH 5,0). Los factores evaluados fueron: relación sólido/líquido, temperatura, tiempo y actividad enzimática. El material polimérico se precipitó con etanol y el peso seco del gel obtenido se denominó material insoluble en etanol (MIE). Se obtuvieron rendimientos de MIE de 35,93±0,67% (p/p), con una relación sólido/líquido de 1/50, 12,5 mL del EE (actividad PGasa en el medio de reacción: 4,28 UE/mL), 40º C, 4 h y pH 5,0. Este valor fue superior al obtenido utilizando el método químico, lo cual confirma la bondad del proceso enzimático utilizado.The objective of the present work was to evaluate the effect of different factors on the extraction of pectin from lemon albedo, using the enzymatic extract with polygalacturonase activity of Wickerhamomyces anomalus (WA strain 110), a native yeast from the Province of Misiones, Argentina. Pectin extraction process was carried out in Erlenmeyer flasks containing lemon albedo, buffer and the crude enzymatic extract of WA strain 110, with agitation (pH 5.0). Factors studied were: solid-liquid ratio, temperature, time and enzyme activity. The soluble polymeric material was precipitated with ethanol and the weight of the dried gel obtained was named as ethanol insoluble material (EIM). It was obtained a yield of MIE of 35.93± 0.67% (w/w), with a solid / liquid ratio of 1/50, 12.5 mL of EE (PGase activity in the reaction medium: 4.28 UE/mL), 40º C, 4 h, and pH 5.0. This value was higher than that obtained using the chemical method, which confirms the goodness of the enzymatic process used

Optimización de las condiciones de cultivo para la producción de una Poligalacturonasa Microbiana

The objective of the present research was to evaluate the effect of the cultivation conditions on the production of a polygalacturonase (PGase) by Wickerhamomyces anomalus. Fermentations were carried out in agitated flasks, in a synthetic medium, varying culture conditions (temperature, pH and agitation). A 23 factorial design was initially applied and then response surface methodology. The macerating capacity of the enzymatic extract on a vegetal tissue was evaluated. PH and temperature significantly influenced the production of PGase enzyme, while the influence of the stirring rate was not significant. The highest titles were obtained at 30°C and pH of 5.1; with a maximum PGase activity of 18.84 EU / mL. The enzymatic extract was able to macerate bell pepper tissues. Enzymatic extracts with high PGase activity were obtained, under selected conditions, of interest in food technology.El objetivo del presente trabajo fue evaluar el efecto de las condiciones de cultivo sobre la producción de una Poligalacturonasa (PGasa) por Wickerhamomyces anomalus. Las fermentaciones se realizaron en frascos agitados, en un medio sintético, variando las condiciones de cultivo (temperatura, pH y velocidad de agitación). Se aplicó inicialmente un diseño factorial 23 y posteriormente la metodología de superficie de respuesta. Se evaluó la capacidad macerante del extracto enzimático sobre un tejido vegetal. El pH y la temperatura influyeron significativamente en la producción de la enzima PGasa, mientras que la influencia de la velocidad de agitación fue no significativa. Los mayores títulos se obtuvieron a 30° C y pH de 5,1; con un valor máximo de actividad PGasa de 18,84 UE/mL. El extracto enzimático fue capaz de macerar tejidos de pimiento morrón. Se obtuvieron extractos enzimáticos con elevada actividad PGasa, en las condiciones seleccionadas, de interés en tecnología de los alimentos

Isolation of a yeast strain able to produce a polygalacturonase with maceration activity of cassava roots

The objective of the present study was the isolation of a yeast strain, from citrus fruit peels, able to produce a polygalacturonase by submerged fermentation with maceration activity of raw cassava roots. Among 160 yeast strains isolated from citrus peels, one strain exhibited the strongest pectinolytic activity. This yeast was identified as Wickerhamomyces anomalus by 5.8S-ITS RFLP analysis and confirmed by amplification of the nucleotide sequence. The yeast produced a polygalacturonase (PG) in Erlenmeyer shake flasks containing YNB, glucose, and citrus pectin. PG synthesis occurred during exponential growth phase, reaching 51 UE.mL-1 after 8 hours of fermentation. A growth yield (Yx/s) of 0.43 gram of cell dry weight per gram of glucose consumed was obtained, and a maximal specific growth rate (µm) of 0.346 h-1 was calculated. The microorganism was unable to assimilate sucrose, galacturonic acid, polygalacturonic acid, or citrus pectin, but it required glucose as carbon and energy source and polygalacturonic acid or citrus pectin as inducers of enzyme synthesis. The crude enzymatic extract of Wickerhamomyces anomalus showed macerating activity of raw cassava. This property is very important in the production of dehydrated mashed cassava, a product of regional interest in the province of Misiones, Argentina

Production of an endopolygalacturonase from Wickerhanomyces anomalus with disintegration activity on plant tissues

The objective of the present study was to produce an endo-polyglacturonase by Wickerhanomyces anomalus, in a low cost fermentation medium, by batch and fed-batch cultures in order to be used in the enzyme. The effect of several nutrients on PGase production, were evaluate at shakes flasks, in a reference fermentation medium, using one factor at a time method, Plackett-Burman design and response surface methodology. The optimized fermentation medium was used to evaluate the growth and production of the enzyme by batch and fed-batch cultures, at a lab scale bioreactor. PGase activity obtained in the RF medium was ∼20 U/mL. The absence of trace element solution had a repressive effect on the enzyme synthesis. The addition of yeast extract, instead of vitamins and amino acids, in the culture medium, improved the production of the enzyme. Plackett-Burman design determined that only pectin and yeast extract had significant and positive effect on PGase production. The Doehlert design determined that maximum PGase synthesis was obtained with 6.0 and 0.8 g/L of pectin and yeast extract, respectively. The final optimized fermentation medium included glucose, pectin, urea, yeast extract and salts. In this medium, PGase synthesis reached ∼25 U/mL, and ∼49 U/mL, in batch and fed-batch cultures, respectively, at lab scale bioreactor. In this study, it was able to obtain enzymatic extract with high PGase activity, by the growth of W. anomalus in a low cost culture medium, by fed-batch system, for its future use in the enzymatic cassava starch extraction.Fil: Maidana, Silvana Andrea. Universidad Nacional de Misiones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Butiuk, Ana Paula. Universidad Nacional de Misiones; Argentina. Centro de Investigacion y Desarrollo En Fermentaciones Industriale; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Zubreski, Emilce Roxana. Universidad Nacional de Misiones; ArgentinaFil: Hours, Roque Alberto. Universidad Tecnológica Nacional. Facultad Reg.la Plata. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Brumovsky, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Martos, María Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin

Changes in the physical, textural and chemical properties of the enriched pasta elaborated with cassava starch

Gluten free pasta contain low protein content. The objective was to improve a formulation already optimized of gluten free pasta, through protein fortification to provide a dry pasta with greater industrial use. Egg albumen powder at three levels (1.0, 1.5 and 2.0 g/100 g) was incorporated. Initially, the optimum drying pasta conditions were determined. Then, the cooking quality parameters of pasta and textural quality by instrumental methods and sensory methods were evaluated. Last, chemical composition, in vitro protein digestibility and shelf life (physicochemical and microbiological stored dry pasta studies) the selected formulation was analyzed. The egg albumen fortified pasta (1.5 g/100 g) showed an increase in the cooking quality values and proteins and fibers contents, a desired decrease in the texture parameters (instrumental and sensory), and satisfactory hygienic conditions up to 8th month of storage. This pasta showed great potential, and its commercial scale development could be a viable option.Fil: Milde, Laura Beatríz. Universidad Nacional de Misiones; ArgentinaFil: Rivero, Donovan Ariel. Universidad Nacional de Misiones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Chigal, Paola Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Cs.exactas Químicas y Naturales. Departamento de Ciencia y Tecnol. de Los Alimentos; ArgentinaFil: Zubreski, Emilce Roxana. Universidad Nacional de Misiones; ArgentinaFil: Chade, Miriam Estela. Universidad Nacional de Misiones; ArgentinaFil: Brumovsky, Luis Alberto. Universidad Nacional de Misiones; Argentin