215 research outputs found
Informe de personal de apoyo: Gortari, María Cecilia (2012-2013)
No full textProyectos de investigación en los cuales colabora:
a) Hongos autóctonos de posible interés económico: aislamiento, identificación, caracterización molecular y su potencial como productores de enzimas con implicancias biotecnológicas (PIP 112-200801-01422) del CONICET. Director: Dra. Angélica Arambarri. Co-director: Dr. Roque A. Hours.
b) Enzimas, microorganismos y procesos de interés biotecnológico. Acreditado y financiado por la SeCyt de la UNLP, código 11/X522. Años 2009-2012. Director: Dr. Roque A. Hours.
c) Proyecto de Investigación Plurianual (PIP 112-201101-00662) del CONICET: Microorganismos, enzimas y procesos biotecnológicos. Res. 1672/12. Años: 2012-2014
In vitro antagonistic activity of Argentinean isolates of Purpureocillium lilacinum on Nacobbus aberrans eggs
No full textIn vitro interaction of three Argentinean isolates of Purpureocillium lilacinum (one isolated from a public park and two from agricultural soils) towards Nacobbus aberrans eggs was studied. After seven incubation days, the three isolates showed reproductive fungal structures fully developed whereas 80 to 100 % of the eggs were infected. No significant differences among the three isolates were observed in fungal activity with respect to hatching and parasitism under the assayed test conditions (p > 0.05). The hatching percentage in control plates increased during the evaluation period of the cultures, with no signs of fungal infection, showing significant differences as compared to the plates infected (p < 0.05). Although the three isolates studied could be considered as potential agents for biological control of root-knot nematodes, it is necessary to further study some aspects in a wide range of experimental conditions in the laboratory, greenhouse and field so as to determine their real efficiency.Fil: Gortari, Maria Cecilia. 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: Hours, Roque 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; Argentin
Reduction of l-phenylalanine in protein hydrolysates using l-phenylalanine ammonia-lyase from Rhodosporidium toruloides
No full textl-Phenylalanine ammonia-lyase (PAL, EC 4.3.1.25) from Rhodosporidium toruloides was utilized to remove l-phenylalanine (l-Phe) from different commercial protein hydrolysates. A casein acid hydrolysate (CAH, l-Phe ~2.28 %) was employed as a model substrate. t-Cinnamic acid resulting from deamination of l-Phe was extracted, analyzed at λ = 290 nm, and used for PAL activity determination. Optimum reaction conditions, optimized using successive Doehlert design, were 35 mg mL−1 of CAH and 800 mU mL−1 of PAL, while temperature and pH were 42 °C and 8.7, respectively. Reaction kinetics of PAL with CAH was determined under optimized conditions. Then, removal of l-Phe from CAH was tested. Results showed that more than 92 % of initial l-Phe was eliminated. Similar results were obtained with other protein hydrolysates. These findings demonstrate that PAL is a useful biocatalyst for l-Phe removal from protein hydrolysates, which can be evaluated as potential ingredients in foodstuffs for PKU patients.Fil: Castañeda, María Teresita. 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: Adachi, Osao. Yamaguchi University; JapónFil: Hours, Roque 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; Argentina. Universidad Tecnológica Nacional; Argentin
IN VITRO ACTIVITY OF PURPUREOCILLIUM LILACINUM ISOLATES AGAINST PHYTOPATHOGENIC FUNGI OF SORGHUM
No full textMetabolites produced by antagonist on the growthof phytopathogens fungus. The three P. lilacinumisolates had variable inhibitory activity accordingto the type of assay and phytopathogen evaluated.However, the inhibition was more evident with P.lilacinum Ls isolate and mainly with the effectof the non-volatile compounds. This studysuggests that P. lilacinum could be considered apromising antagonist in the control of Alternaria.These results motivate us to go deeper in theproduction, isolation and identification of thecompounds produced by this specie. The studiedP. lilacinum Ls isolate could be another tool in thedifferent biological control strategies applied tothe conservation of sorghum grains.Fil: Gortari, Maria Cecilia. 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: Hours, Roque 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: Astoreca, Andrea Luciana. 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
Biotechnological processes for chitin recovery out of crustacean waste: A mini-review
No full textAbstract Background: Chitin is an important natural resource. The annual worldwide production is estimated in approximately 1010-1012 ton. It is produced by arthropods (insects and crustaceans), molluscs and fungi. Its main biological function is structural. Crustacean shells are the most important chitin source for commercial use due to its high content and ready availability. Chitin and its derivatives have great economical value because of their numerous applications: food, cosmetics, pharmaceuticals, textile industries, waste water treatment and agriculture. In nature, chitin is closely associated with proteins, minerals, lipid and pigments, which have to be removed. Results: Several techniques to extract chitin from different sources have been reported. The most common method for recovery of chitin from crustacean shells is the chemical procedure. It involves two mayor steps: elimination of inorganic matter (demineralization) and extraction of protein matter (deproteination) using strong acids and bases. However, these processes may cause depolymerization affecting the polymer properties such as molecular weight, viscosity and degree of acetylation. In addition, the chemical purification of chitin is hazardous, energy consuming and threatening to the environment. As an alternative to the chemical process, different biological processes have been investigated: microbiological fermentation and methodologies using enzymatic crude extracts or isolated enzymes. Conclusions: The results reported are extremely variable; however, they offer new perspectives for the production of chitin with the concomitant reduction of the environmental impact.Fil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales (i); ArgentinaFil: Gortari, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales (i); Argentin
Protopectinasa-se de Geotrichum klebahnii: Estudios de adsorción y capacidad de solubilización de pectina
No full textProtopectinasa-SE (PPasa-SE) es una poligalacturonasa producida por Geotrichum klebahnii con capacidad de liberar pectina por hidrólisis de protopectina. La reacción de liberación de pectina responde a un sistema de catálisis heterogenea, donde la interacción enzima-protopectina y la liberación de pectina, son objetivos de esta investigación. La interacción enzima-protopectina resultó dependiente del tamaño y estructura de las partículas del sustrato, así como de la naturaleza de la solución amortiguadora. Para partículas pequeñas la cinética de adsorción siguió un comportamiento definido por la isoterma de Langmuir. La reacción respondió al modelo cinético de Michaelis-Menten, con valores de Km y Vmax de 30.2 g/L y 57.3 g/L.h. Los mejores resultados en cuanto a la adsorción de la enzima y la solubilización de pectina fueron obtenidos con una solución amortiguadora de citrato y citrato-fosfato. Este trabajo constituye un primer reporte en cuanto a la solubilización de pectina que involucra un modelo de unión al sustrato asociado en sistemas pectinasa-protopectinasa.Protopectinase SE (PPase-SE) is a polygalacturonase produced by Geotrichum klebahnii with the capacity to liberate pectin through protopectin hydrolysis. The protopectin cleavage is a typical heterogeneous-catalysis reaction whose interaction between the enzyme and the protopectin substrate from lemon albedo along with the release of the pectin-reaction product were the objectives of this investigation. The interaction between PPase-SE and protopectin depended on the particle size and the structure of the substrate as well as on the nature of the buffer. The adsorption kinetics follows, for small particles, a Langmuir isotherm pattern. The reaction exhibited Michaelis-Menten kinetics, giving respective apparent-Km and Vmax values of 30.2 g/l and 57.3 g/l.h. The better results in enzyme adsorption and pectin releasing were obtained with citrate and citrate-phosphate buffers. This report constitutes the first investigation in pectin solubilization involving a model for the substrate-binding mechanism within the pectinase-protopectinase system.Fil: Zapata Zapata, Arley David. Universidad Nacional de Colombia; ColombiaFil: Hours, Roque 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: Cavalitto, Sebastian Fernando. 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
Yerba mate as a novel inducer for fungal chlorogenate hydrolase production
No full textThe potential of yerba mate (Ilex paraguariensis) to induce chlorogenate hydrolase (EC 3.1.1.42, CHase) activity in different fungal strains has been investigated. CHase was highly induced in mycelia of Aspergillus niger AKU 3302 grown in Czapek medium containing yerba mate extract as inducer. Different materials derived from yerba mate processing were examined as CHase activity inducers. All yerba mate samples produced CHase activity and a concentrated aqueous yerba mate extract was selected as the most convenient inducer. A response surface methodology was used to assess the simultaneous effect of inducer concentration and induction duration on enzyme production. The experimental design revealed that the optimum CHase production was achieved after long induction times (≥25 h) and low inducer concentrations (0.1–0.2% w/v, dry basis).Fil: Butiuk, Ana Paula. 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 Cs.exactas. Centro de Investigación y Desarrollo En Fermentaciones Industriales; ArgentinaFil: Adachi, Osao. Yamaguchi University; JapónFil: Hours, Roque 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 Cs.exactas. Centro de Investigación y Desarrollo En Fermentaciones Industriales; Argentin
5-Keto-D-fructose production from sugar alcohol by isolated wild strain Gluconobacter frateurii CHM 43
No full textGluconobacter frateurii: CHM 43 have D-mannitol dehydrogenase (quinoprotein glycerol dehydrogenase) and flavoprotein D-fructose dehydrogenase in the membranes. When the two enzymes are functional, D-mannitol is converted to 5-keto-D-fructose with 65% yield when cultivated on D-mannitol. 5-Keto-D-fructose production with almost 100% yield was realized with the resting cells. The method proposed here should give a smart strategy for 5-keto-D-fructose production.Fil: Adachi, Osao. Yamaguchi University; JapónFil: Nguyen, Thuy M.. Yamaguchi University; JapónFil: Hours, Roque 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: Kataoka, Naoya. Yamaguchi University; JapónFil: Matsushita, Kazunobu. Yamaguchi University; JapónFil: Akakabe, Yoshihiko. Yamaguchi University; JapónFil: Yakushi, Toshiharu. Yamaguchi University; Japó
Enzymatic Synthesis of 4-Pentulosonate (4-Keto-<scp>D</scp>-pentonate) from<scp>D</scp>-Aldopentose and<scp>D</scp>-Pentonate by Two Different Pathways Using Membrane Enzymes of Acetic Acid Bacteria
No full text4-Keto-D-arabonate (D-threo-pent-4-ulosonate) and 4-keto-D-ribonate (D-erythro-pent-4-ulosonate) were prepared from D-arabinose and D-ribose by two successive reactions of membrane-bound enzymes, D-aldopentose 4-dehydrogenase and 4-keto-D-aldopentose 1-dehydrogenase of Gluconobacter suboxydans IFO 12528. Alternatively, they were prepared from D-arabonate and D-ribonate with another membrane-bound enzyme, Dpentonate 4-dehydrogenase. Analytical data confirmed the chemical structures of the 4-pentulosonates prepared. This is the first report of successful enzymatic synthesis of 4-pentulosonates.Fil: Adachi, Osao. Yamaguchi University; JapónFil: Hours, Roque 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: Shinagawa, Emiko. No especifíca;Fil: Akakabe, Yoshihiko. Yamaguchi University; JapónFil: Yakushi, Toshiharu. Yamaguchi University; JapónFil: Matsushita, Kazunobu. Yamaguchi University; Japó
Enzymatic hydrolysis of gelatin layers of X-ray films and release of silver particles using keratinolytic serine proteases from Purpureocillium lilacinum LPS # 876
No full textEnzymatic decomposition of gelatin layers on used X-ray films and repeated utilization of the enzyme for potential application in silver recovery were investigated using keratinolytic serine proteases from Purpureocillium lilacinum LPS # 876. At pH 9.0, the enzymatic reaction was enhanced by the increase of enzyme concentration or by the increase of the temperature up to 60oC. Under the conditions of 6.9 U/ml, 60oC, and pH 9.0, hydrolysis of the gelatin layers and the resulting release of silver particles were achieved within 6 min. The protective effect of polyols against thermal denaturation was investigated. The presence of glycerol and propylene glycol increased enzyme stability. When the reusability of the enzyme for gelatin hydrolysis was tested, it could be seen that it could be effectively reused for more cycles when glycerol was added, compared with the enzyme without protective agents. The results of these repeated treatments suggested that a continuous process of recycling silver from used X-ray is feasible. Keeping in mind that recycling is (at the present time) needed and imperative, it can be remarked that, in this research, three wastes were successfully used: hair waste in order to produce serine proteases; glycerol in order to enhance enzyme thermal stability; and used Xray films in order to recover silver and PET films.Fil: Cavello, Ivana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Fermentaciones Industriales (i); ArgentinaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Fermentaciones Industriales (i); ArgentinaFil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Fermentaciones Industriales (i); Argentin
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