6 research outputs found
Estudio del metabolismo energ茅tico de <i>Geotrichum klebahnii</i>
El g茅nero Geotrichum esta comprendido dentro del phylum ascomycota. Los miembros de este g茅nero son hongos levaduriformes caracterizados por hifas estrechas con ramificaciones escasas y cortas. No poseen blastoconidias, conidioforos ni pseudohifas pero si presentan artroconidias con un tama帽o promedio de 6-12 x 3-6 碌m, unicelulares, en cadena, hialinas que resultan de la fragmentaci贸n de hifas indiferenciadas por fisi贸n mediante la formaci贸n de septos dobles. Pueden ser rectangulares o poseer los extremos redondeados asemej谩ndose a peque帽os barriles. La ausencia de c茅lulas vac铆as que al fragmentarse produzcan la liberaci贸n de las artroconidias (c茅lulas separadoras) es t铆pica de este genero.
Geotrichum posee en medio s贸lido un crecimiento r谩pido con la formaci贸n de colonias blancas secas con aspecto de algod贸n. En medios ricos al final de la fase de crecimiento genera un fuerte aroma a fruta.Facultad de Ciencias Exacta
Estudio del metabolismo energ茅tico de <i>Geotrichum klebahnii</i>
El g茅nero Geotrichum esta comprendido dentro del phylum ascomycota. Los miembros de este g茅nero son hongos levaduriformes caracterizados por hifas estrechas con ramificaciones escasas y cortas. No poseen blastoconidias, conidioforos ni pseudohifas pero si presentan artroconidias con un tama帽o promedio de 6-12 x 3-6 碌m, unicelulares, en cadena, hialinas que resultan de la fragmentaci贸n de hifas indiferenciadas por fisi贸n mediante la formaci贸n de septos dobles. Pueden ser rectangulares o poseer los extremos redondeados asemej谩ndose a peque帽os barriles. La ausencia de c茅lulas vac铆as que al fragmentarse produzcan la liberaci贸n de las artroconidias (c茅lulas separadoras) es t铆pica de este genero.
Geotrichum posee en medio s贸lido un crecimiento r谩pido con la formaci贸n de colonias blancas secas con aspecto de algod贸n. En medios ricos al final de la fase de crecimiento genera un fuerte aroma a fruta.Facultad de Ciencias Exacta
Optimiranje proizvodnje poligalakturonaze iz Aspergillus kawachii, klonirane u Saccharomyces cerevisiae, u 拧ar啪nom i prihranjivanom 拧ar啪nom uzgoju
Polygalacturonases (PG; EC 3.2.1.15) catalyze the hydrolysis of pectin and/or pectic acid and are useful for industrial applications such as juice clarification and pectin extraction. Growth and heterologous expression of recombinant Saccharomyces cerevisiae which expresses an acidic PG from Aspergillus kawachii has been studied in batch and fed-batch cultures. Kinetics and stoichiometric parameters of the recombinant yeast were determined in batch cultures in a synthetic medium. In these cultures, the total biomass concentration, protein concentration, and enzyme activity achieved were 2.2 g/L, 10 mg/L, and 3 U/mL, respectively, to give a productivity of 0.06 U/(mL路h). In fed-batch cultures, various strategies
for galactose feeding were used: (i) after a glucose growth phase, the addition of a single pulse of galactose which gave a productivity of 0.19 U/(mL路h); (ii) after a glucose growth phase, a double pulse of galactose at the same final concentration was added, resulting in a productivity of 0.21 U/(mL路h); (iii) a simultaneous feeding of glucose and galactose, yielding a productivity of 1.32 U/(mL路h). Based on these results, the simultaneous feeding of glucose and galactose was by far the most suitable strategy for the production of this enzyme. Moreover, some biochemical characteristics of the recombinant enzyme such as a molecular mass of ~60 kDa, an isoelectric point of 3.7 and its ability to hydrolyze polygalacturonic acid at pH=2.5 were determined.Poligalakturonaze (EC 3.2.1.15) kataliziraju hidrolizu pektina i/ili pektinske kiseline i mogu se primijeniti u prehrambenoj industriji, npr. za bistrenje soka ili ekstrakciju pektina. U radu je ispitan rast rekombinantnog kvasca Saccharomyces cerevisiae, te heterologna ekspresija kisele poligalakturonaze iz Aspergillus kawachii u 拧ar啪nom i prihranjivanom 拧ar啪nom uzgoju. U sinteti膷kom su mediju 拧ar啪nim uzgojem odre膽eni kineti膷ki i stehiometrijski parametri rekombinantnog kvasca. Pritom su dobivene ove vrijednosti: koncentracija ukupne biomase od 2,2 g/L; koncentracija proteina od 10 mg/L; enzimska aktivnost od 3 U/mL i produktivnost od 0,006 U/(mL路h). U prihranjivanom su 拧ar啪nom uzgoju primijenjene razne strategije prihranjivanja galaktozom: (i) nakon 拧to kvasac utro拧i glukozu za rast, jednokratnim dodatkom galaktoze posti啪e se produktivnost od 0,19 U/(mL路h); (ii) nakon utro拧ka glukoze, dvaput se doda galaktoza u jednakim koncentracijama, pri 膷emu je produktivnost 0,21 U/(mL路h) i (iii) simultanim prihranjivanjem glukozom i galaktozom dobivena je produktivnost od 1,32 U/(mL路h). Zaklju膷eno je da se najbolji rezultati posti啪u simultanim prihranjivanjem glukozom i galaktozom. Odre膽ene su i biokemijske zna膷ajke rekombinantnog enzima: molekularna masa od pribli啪no 60 kDa, izoelektri膷na to膷ka od 3,7 i sposobnost enzima da hidrolizira poligalakturonsku kiselinu pri pH=2,5
Optimization of the Production of a Polygalacturonase from Aspergillus kawachii cloned in Saccharomyces cerevisiae in batch and fed-batch cultures
Polygalacturonases (PG; EC 3.2.1.15) catalyze the hydrolysis of pectin and/or pectic acid and are useful for industrial applications such as juice clarification and pectin extraction. Growth and heterologous expression of recombinant S. cerevisiae which expresses an acidic PG from Aspergillus kawachii was studied in batch and fed batch cultures. Kinetics and stoichiometric parameters of the recombinant yeast were determined in batch cultures in a synthetic medium. In these cultures, the total biomass concentration, protein concentration, and enzyme activity achieved were 2.2 g/l, 10 mg/l, and 3 U/ml, respectively, to give a productivity of 0.06 U/ml.h. In fed batch cultures, various strategies for galactose feeding were used: a) after a glucose growth phase, the addition of a single pulse of galactose which gave a productivity of 0.19 U/ml.h.; b) after a glucose growth phase, a double pulse of galactose at the same final concentration, resulting in a productivity of 0.21 U/ml.h.; c) a simultaneous feeding of glucose and galactose, yielding a productivity of 1.32 U/ml.h. Based on these results, the simultaneous feeding of glucose and galactose was by far the most suitable strategy for the production of this enzyme. Moreover, some biochemical characteristics of the recombinant enzyme such as a MW of ~60 kDa, an isoelectric point of 3.7 and its ability to hydrolyze polygalacturonic acid at pH 2.5 were determined.Fil: Rojas, Natalia Lorena. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Ortiz, Gast贸n Ezequiel. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Chesini, Mariana. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Baruque, Diego Jorge. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Instituto de Biolog铆a y Medicina Experimental. Fundaci贸n de Instituto de Biolog铆a y Medicina Experimental. Instituto de Biolog铆a y Medicina Experimental; ArgentinaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; Argentin
Optimization of the Production of Polygalacturonase from Aspergillus kawachii Cloned in Saccharomyces cerevisiae in Batch and Fed-Batch Cultures
Polygalacturonases (PG; EC 3.2.1.15) catalyze the hydrolysis of pectin and/or pectic acid and are useful for industrial applications such as juice clarification and pectin extraction. Growth and heterologous expression of recombinant Saccharomyces cerevisiae which expresses an acidic PG from Aspergillus kawachii has been studied in batch and fed-batch cultures. Kinetics and stoichiometric parameters of the recombinant yeast were determined in batch cultures in a synthetic medium. In these cultures, the total biomass concentration, protein concentration, and enzyme activity achieved were 2.2 g/L, 10 mg/L, and 3 U/mL, respectively, to give a productivity of 0.06 U/(mL路h). In fed-batch cultures, various strategies
for galactose feeding were used: (i) after a glucose growth phase, the addition of a single pulse of galactose which gave a productivity of 0.19 U/(mL路h); (ii) after a glucose growth phase, a double pulse of galactose at the same final concentration was added, resulting in a productivity of 0.21 U/(mL路h); (iii) a simultaneous feeding of glucose and galactose, yielding a productivity of 1.32 U/(mL路h). Based on these results, the simultaneous feeding of glucose and galactose was by far the most suitable strategy for the production of this enzyme. Moreover, some biochemical characteristics of the recombinant enzyme such as a molecular mass of ~60 kDa, an isoelectric point of 3.7 and its ability to hydrolyze polygalacturonic acid at pH=2.5 were determined
High level production of a recombinant acid stable exoinulinase from Aspergillus kawachii
Exoinulinases鈥攅nzymes extensively studied in recent decades because of their industrial applications鈥攏eed to be produced in suitable quantities in order to meet production demands. We describe here the production of an acid-stable recombinant inulinase from Aspergillus kawachii in the Pichia pastoris system and the recombinant enzyme's biochemical characteristics and potential application to industrial processes. After an appropriate cloning strategy, this genetically engineered inulinase was successfully overproduced in fed-batch fermentations, reaching up to 840 U/ml after a 72-h cultivation. The protein, purified to homogeneity by chromatographic techniques, was obtained at a 42% yield. The following biochemical characteristics were determined: the enzyme had an optimal pH of 3, was stable for at least 3鈥痟鈥痑t 55鈥癈, and was inhibited in catalytic activity almost completely by Hg+2. The respective Km and Vmax for the recombinant inulinase with inulin as substrate were 1.35鈥痬M and 2673鈥糾ol/min/mg. The recombinant enzyme is an exoinulinase but also possesses synthetic activity (i. e., fructosyl transferase). The high level of production of this recombinant plus its relevant biochemical properties would argue that the process presented here is a possible recourse for industrial applications in carbohydrate processing.Fil: Chesini, Mariana. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Plaza Caz贸n, Josefina del Carmen. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnolog铆a; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; ArgentinaFil: Baruque, Diego Jorge. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnolog铆a; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; ArgentinaFil: Vita, Carolina Elena. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - La Plata. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci贸n y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Ghiringhelli, Pablo Daniel. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnolog铆a; ArgentinaFil: Rojas, Natalia Lorena. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnolog铆a; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; Argentin