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1.
Rev Argent Microbiol ; 35(3): 128-32, 2003.
Artículo en Español | MEDLINE | ID: mdl-14587373

RESUMEN

The production of rennet was studied, using different strains of the fungus Rhizomucor miehei. The selection and preservation of strains, type of growth, media design and operation conditions were evaluated. The experiments were carried out in Erlenmeyer flasks in rotary shaker at 250 rpm and 2.5 eccentricity, and in mechanically stirred fermentors of the New Brunswick type, at 30 degrees C. In the studies concerning strain selection, the best strain was Rhizomucor miehei NRRL 3169. The major titles of enzyme were obtained in batch process at 168 h, with 884 SU/ml, whereas in mechanically stirred fermentors the best value was 1160 SU/ml. These values were far more superior to former ones published by various experts.


Asunto(s)
Quimosina/biosíntesis , Proteínas Fúngicas/biosíntesis , Rhizomucor/enzimología , Fermentación , Microbiología Industrial , Rhizomucor/clasificación , Rhizomucor/crecimiento & desarrollo , Especificidad de la Especie
2.
Rev Argent Microbiol ; 35(2): 57-61, 2003.
Artículo en Español | MEDLINE | ID: mdl-12920984

RESUMEN

In this paper the influence of the exopolysaccharides produced by Sinorhizobium meliloti strains on the nodulation rates in alfalfa plants has been considered. The experiments were performed in a rotary shaker and in an air-lift type fermentor. Different Sinorhizobium meliloti strains were used. Bacterial growth rates were determined by viable cell counts. Exopolysaccharide concentration was determined by precipitation with ethanol. It was observed that maximum cell concentration was in the order of 1 x 10(10) cell/ml and exopolysaccharide content was approximately 11 g/l. The experiments performed with alfalfa plants in a controlled environment chamber showed that, when inoculation was carried out with diluted suspensions (1/10), nodulation time was reduced from 10 to 4 days, while the strains retained their symbiotic properties.


Asunto(s)
Técnicas Bacteriológicas/instrumentación , Medicago sativa/microbiología , Polisacáridos Bacterianos/biosíntesis , Sinorhizobium/crecimiento & desarrollo , Aerobiosis , Medios de Cultivo/metabolismo , Fermentación , Oxígeno/farmacología , Sinorhizobium/efectos de los fármacos , Sinorhizobium/metabolismo , Factores de Tiempo
3.
Rev. argent. microbiol ; Rev. argent. microbiol;35(2): 57-61, abr.-jun. 2003.
Artículo en Español | BINACIS | ID: bin-4857

RESUMEN

En este trabajo, se estudió la influencia de los polisacáridos formados por cepas de Sinorhizobium meliloti sobre la velocidad de nodulación en plantas de alfalfa. Las experiencias fueron realizadas en agitador rotatorio y en un fermentador con circulación de líquido por inyección de aire, empleando diferentes cepas de S. meliloti, El crecimiento bacteriano fue determinado por recuento de células viables y la concentración del exopolisacárido por precipitación con etanol. Se alcanzaron concentraciones máximas del orden de 1.10 (10) células viables/ml y de 11 g/l de polisacárido. Los estudios de crecimiento de plantas de alfalfa en cámara climatizada mostraron que se producía una reducción en el tiempo de aparición de nódulos de 10 a 4 días, cuando las mismas eran inoculadas con suspensiones diluidas 1/10, manteniendo las cepas sus propiedades simbióticas. (AU)


Asunto(s)
Sinorhizobium meliloti , Polisacáridos Bacterianos , Argentina
4.
Rev. argent. microbiol ; Rev. argent. microbiol;35(2): 57-61, abr.-jun. 2003.
Artículo en Español | LILACS | ID: lil-356630

RESUMEN

En este trabajo, se estudió la influencia de los polisacáridos formados por cepas de Sinorhizobium meliloti sobre la velocidad de nodulación en plantas de alfalfa. Las experiencias fueron realizadas en agitador rotatorio y en un fermentador con circulación de líquido por inyección de aire, empleando diferentes cepas de S. meliloti, El crecimiento bacteriano fue determinado por recuento de células viables y la concentración del exopolisacárido por precipitación con etanol. Se alcanzaron concentraciones máximas del orden de 1.10 (10) células viables/ml y de 11 g/l de polisacárido. Los estudios de crecimiento de plantas de alfalfa en cámara climatizada mostraron que se producía una reducción en el tiempo de aparición de nódulos de 10 a 4 días, cuando las mismas eran inoculadas con suspensiones diluidas 1/10, manteniendo las cepas sus propiedades simbióticas.


Asunto(s)
Argentina , Polisacáridos Bacterianos , Sinorhizobium meliloti
5.
Rev. argent. microbiol ; Rev. argent. microbiol;35(2): 57-61, 2003 Apr-Jun.
Artículo en Español | BINACIS | ID: bin-38913

RESUMEN

In this paper the influence of the exopolysaccharides produced by Sinorhizobium meliloti strains on the nodulation rates in alfalfa plants has been considered. The experiments were performed in a rotary shaker and in an air-lift type fermentor. Different Sinorhizobium meliloti strains were used. Bacterial growth rates were determined by viable cell counts. Exopolysaccharide concentration was determined by precipitation with ethanol. It was observed that maximum cell concentration was in the order of 1 x 10(10) cell/ml and exopolysaccharide content was approximately 11 g/l. The experiments performed with alfalfa plants in a controlled environment chamber showed that, when inoculation was carried out with diluted suspensions (1/10), nodulation time was reduced from 10 to 4 days, while the strains retained their symbiotic properties.

6.
Rev. argent. microbiol ; Rev. argent. microbiol;35(3): 128-32, 2003 Jul-Sep.
Artículo en Español | BINACIS | ID: bin-38865

RESUMEN

The production of rennet was studied, using different strains of the fungus Rhizomucor miehei. The selection and preservation of strains, type of growth, media design and operation conditions were evaluated. The experiments were carried out in Erlenmeyer flasks in rotary shaker at 250 rpm and 2.5 eccentricity, and in mechanically stirred fermentors of the New Brunswick type, at 30 degrees C. In the studies concerning strain selection, the best strain was Rhizomucor miehei NRRL 3169. The major titles of enzyme were obtained in batch process at 168 h, with 884 SU/ml, whereas in mechanically stirred fermentors the best value was 1160 SU/ml. These values were far more superior to former ones published by various experts.

7.
Rev. argent. microbiol ; Rev. argent. microbiol;35(3): 128-32, 2003 Jul-Sep.
Artículo en Español | LILACS-Express | LILACS, BINACIS | ID: biblio-1171726

RESUMEN

The production of rennet was studied, using different strains of the fungus Rhizomucor miehei. The selection and preservation of strains, type of growth, media design and operation conditions were evaluated. The experiments were carried out in Erlenmeyer flasks in rotary shaker at 250 rpm and 2.5 eccentricity, and in mechanically stirred fermentors of the New Brunswick type, at 30 degrees C. In the studies concerning strain selection, the best strain was Rhizomucor miehei NRRL 3169. The major titles of enzyme were obtained in batch process at 168 h, with 884 SU/ml, whereas in mechanically stirred fermentors the best value was 1160 SU/ml. These values were far more superior to former ones published by various experts.

8.
Rev Argent Microbiol ; 34(1): 15-21, 2002.
Artículo en Español | MEDLINE | ID: mdl-11942079

RESUMEN

The present work studies the production of pectinases using a strain of Penicillium simplicissimum A3263 and considering the influence of adding Amaranthus cruentus seed meal in a selected medium. We also considered the influence of aeration on enzyme production. Research was oriented towards the production of pectin lyase, the enzyme having the highest commercial value. This work was carried out in Erlenmeyer flasks in rotary shaker to select the medium and in a mechanically stirred fermentor to study aeration. The microorganism was developed as pellets of 1 mm diameter. Enzyme levels were of the order of 8216.21 pectin lyase units and 167.57 polygalacturonase units per gram of fungal biomass, respectively, using a medium containing 40 g/l of amaranth seed meal. As for the influence of aeration, it was determined that the higher values were obtained at 750 rpm corresponding to an oxygen absorption rate of 2691 ml O2/lh for an air flow of 1 l/l.min. The results obtained are considered very important in view of the fact that they exceeded in 550% those obtained by other authors.


Asunto(s)
Amaranthus , Medios de Cultivo/farmacología , Proteínas Fúngicas/biosíntesis , Microbiología Industrial/métodos , Penicillium/enzimología , Poligalacturonasa/biosíntesis , Polisacárido Liasas/biosíntesis , Aerobiosis , Biomasa , Carbono/metabolismo , Fermentación , Harina , Oxígeno/metabolismo , Penicillium/efectos de los fármacos , Penicillium/crecimiento & desarrollo , Semillas
9.
Rev. argent. microbiol ; Rev. argent. microbiol;34(1): 15-21, 2002 Jan-Mar.
Artículo en Español | BINACIS | ID: bin-39270

RESUMEN

The present work studies the production of pectinases using a strain of Penicillium simplicissimum A3263 and considering the influence of adding Amaranthus cruentus seed meal in a selected medium. We also considered the influence of aeration on enzyme production. Research was oriented towards the production of pectin lyase, the enzyme having the highest commercial value. This work was carried out in Erlenmeyer flasks in rotary shaker to select the medium and in a mechanically stirred fermentor to study aeration. The microorganism was developed as pellets of 1 mm diameter. Enzyme levels were of the order of 8216.21 pectin lyase units and 167.57 polygalacturonase units per gram of fungal biomass, respectively, using a medium containing 40 g/l of amaranth seed meal. As for the influence of aeration, it was determined that the higher values were obtained at 750 rpm corresponding to an oxygen absorption rate of 2691 ml O2/lh for an air flow of 1 l/l.min. The results obtained are considered very important in view of the fact that they exceeded in 550


those obtained by other authors.

10.
Rev. argent. microbiol ; Rev. argent. microbiol;34(1): 15-21, 2002 Jan-Mar.
Artículo en Español | LILACS-Express | LILACS, BINACIS | ID: biblio-1171702

RESUMEN

The present work studies the production of pectinases using a strain of Penicillium simplicissimum A3263 and considering the influence of adding Amaranthus cruentus seed meal in a selected medium. We also considered the influence of aeration on enzyme production. Research was oriented towards the production of pectin lyase, the enzyme having the highest commercial value. This work was carried out in Erlenmeyer flasks in rotary shaker to select the medium and in a mechanically stirred fermentor to study aeration. The microorganism was developed as pellets of 1 mm diameter. Enzyme levels were of the order of 8216.21 pectin lyase units and 167.57 polygalacturonase units per gram of fungal biomass, respectively, using a medium containing 40 g/l of amaranth seed meal. As for the influence of aeration, it was determined that the higher values were obtained at 750 rpm corresponding to an oxygen absorption rate of 2691 ml O2/lh for an air flow of 1 l/l.min. The results obtained are considered very important in view of the fact that they exceeded in 550


those obtained by other authors.

11.
Rev. argent. microbiol ; Rev. argent. microbiol;32(4): 185-189, oct.-dec. 2000.
Artículo en Español | BINACIS | ID: bin-6738

RESUMEN

In this paper the influence of the amaranth seed meal and the aeration conditions on the alpha-amylase production by Aspergillus niger NRRL 3112 were studied. The assays of selection of culture medium were carried out in a rotary shaker at 250 rpm and 2.5 cm stroke. The aeration conditions were studied in a mechanically stirred fermentor New Brunswick type. A concentration of alpha-amylase of 2750 U.Dun/ml was achieved at 120 h with a dry weight of 8.0 g/l, using a base medium with 5.0 g/l Amaranthus cruentus seed meal. In the experiment performed in a New Brunswick fermentor, the highest value was 2806 U.Dun/ml. This result was obtained after 120 h, operating at 300 rpm and an airflow of 1 l/l. min. in a limited dissolved oxygen concentration. It was determined that the increase in the agitation rate was not favorable to the enzyme production, despite that an increase was verified in the dissolved oxygen. The morphology of the microorganism, in long and ramified hyphae, was the critical factor to obtain higher levels of alpha-amylase.(AU)


Asunto(s)
Colorante de Amaranto/farmacología , Aspergillus niger/efectos de los fármacos , Medios de Cultivo/química , Colorantes/farmacología , Proteínas Fúngicas/biosíntesis , Indicadores y Reactivos/farmacología , alfa-Amilasas/biosíntesis , Aspergillus niger/enzimología , Aspergillus niger/crecimiento & desarrollo , Fermentación
12.
Rev. argent. microbiol ; Rev. argent. microbiol;32(4): 185-189, oct.-dec. 2000.
Artículo en Español | LILACS | ID: lil-332515

RESUMEN

In this paper the influence of the amaranth seed meal and the aeration conditions on the alpha-amylase production by Aspergillus niger NRRL 3112 were studied. The assays of selection of culture medium were carried out in a rotary shaker at 250 rpm and 2.5 cm stroke. The aeration conditions were studied in a mechanically stirred fermentor New Brunswick type. A concentration of alpha-amylase of 2750 U.Dun/ml was achieved at 120 h with a dry weight of 8.0 g/l, using a base medium with 5.0 g/l Amaranthus cruentus seed meal. In the experiment performed in a New Brunswick fermentor, the highest value was 2806 U.Dun/ml. This result was obtained after 120 h, operating at 300 rpm and an airflow of 1 l/l. min. in a limited dissolved oxygen concentration. It was determined that the increase in the agitation rate was not favorable to the enzyme production, despite that an increase was verified in the dissolved oxygen. The morphology of the microorganism, in long and ramified hyphae, was the critical factor to obtain higher levels of alpha-amylase.


Asunto(s)
alfa-Amilasas , Colorante de Amaranto , Aspergillus niger , Colorantes , Medios de Cultivo , Indicadores y Reactivos , Proteínas Fúngicas/biosíntesis , Aspergillus niger , Fermentación
13.
Rev Argent Microbiol ; 32(4): 185-9, 2000.
Artículo en Español | MEDLINE | ID: mdl-11149149

RESUMEN

In this paper the influence of the amaranth seed meal and the aeration conditions on the alpha-amylase production by Aspergillus niger NRRL 3112 were studied. The assays of selection of culture medium were carried out in a rotary shaker at 250 rpm and 2.5 cm stroke. The aeration conditions were studied in a mechanically stirred fermentor New Brunswick type. A concentration of alpha-amylase of 2750 U.Dun/ml was achieved at 120 h with a dry weight of 8.0 g/l, using a base medium with 5.0 g/l Amaranthus cruentus seed meal. In the experiment performed in a New Brunswick fermentor, the highest value was 2806 U.Dun/ml. This result was obtained after 120 h, operating at 300 rpm and an airflow of 1 l/l. min. in a limited dissolved oxygen concentration. It was determined that the increase in the agitation rate was not favorable to the enzyme production, despite that an increase was verified in the dissolved oxygen. The morphology of the microorganism, in long and ramified hyphae, was the critical factor to obtain higher levels of alpha-amylase.


Asunto(s)
Colorante de Amaranto/farmacología , Aspergillus niger/efectos de los fármacos , Colorantes/farmacología , Medios de Cultivo/química , Proteínas Fúngicas/biosíntesis , Indicadores y Reactivos/farmacología , alfa-Amilasas/biosíntesis , Aspergillus niger/enzimología , Aspergillus niger/crecimiento & desarrollo , Fermentación
14.
Rev. argent. microbiol ; Rev. argent. microbiol;32(4): 185-9, 2000 Oct-Dec.
Artículo en Español | BINACIS | ID: bin-39732

RESUMEN

In this paper the influence of the amaranth seed meal and the aeration conditions on the alpha-amylase production by Aspergillus niger NRRL 3112 were studied. The assays of selection of culture medium were carried out in a rotary shaker at 250 rpm and 2.5 cm stroke. The aeration conditions were studied in a mechanically stirred fermentor New Brunswick type. A concentration of alpha-amylase of 2750 U.Dun/ml was achieved at 120 h with a dry weight of 8.0 g/l, using a base medium with 5.0 g/l Amaranthus cruentus seed meal. In the experiment performed in a New Brunswick fermentor, the highest value was 2806 U.Dun/ml. This result was obtained after 120 h, operating at 300 rpm and an airflow of 1 l/l. min. in a limited dissolved oxygen concentration. It was determined that the increase in the agitation rate was not favorable to the enzyme production, despite that an increase was verified in the dissolved oxygen. The morphology of the microorganism, in long and ramified hyphae, was the critical factor to obtain higher levels of alpha-amylase.

15.
Rev. argent. microbiol ; Rev. argent. microbiol;27(3): 146-55, jul.-sept. 1995.
Artículo en Español | LILACS-Express | LILACS, BINACIS | ID: biblio-1171647

RESUMEN

Xanthan production from Xanthomonas campestris was studied by a mechanically shaken fermentor. Influence of glucose concentration, aeration of culture media, rheology of broths and pH control was evaluated. Different aeration conditions based on variation of stirring rates were assayed. Substrate concentration was determined according to the Miller method, and polymer production was performed by the Cadmus method. The higher xanthan levels (i.e. 2.3


) were obtained at 750 rpm, with 1 v/v. min. In such conditions, viscosity ranges about 7000 cPoise and a low level of dissolved oxygen were detected in the culture medium. Xanthan production was influenced by the glucose concentration and the presence of amaranth within the culture medium. In the processes wherein an automatic control of pH was performed, the polymer concentration did not increase regarding to processes involving regular pH evolution.

16.
Rev Argent Microbiol ; 27(3): 146-55, 1995.
Artículo en Español | MEDLINE | ID: mdl-8588053

RESUMEN

Xanthan production from Xanthomonas campestris was studied by a mechanically shaken fermentor. Influence of glucose concentration, aeration of culture media, rheology of broths and pH control was evaluated. Different aeration conditions based on variation of stirring rates were assayed. Substrate concentration was determined according to the Miller method, and polymer production was performed by the Cadmus method. The higher xanthan levels (i.e. 2.3%) were obtained at 750 rpm, with 1 v/v. min. In such conditions, viscosity ranges about 7000 cPoise and a low level of dissolved oxygen were detected in the culture medium. Xanthan production was influenced by the glucose concentration and the presence of amaranth within the culture medium. In the processes wherein an automatic control of pH was performed, the polymer concentration did not increase regarding to processes involving regular pH evolution.


Asunto(s)
Microbiología Industrial/métodos , Polisacáridos Bacterianos/aislamiento & purificación , Xanthomonas campestris/metabolismo , Aerobiosis , Técnicas Bacteriológicas/instrumentación , Medios de Cultivo , Fermentación , Glucosa , Microbiología Industrial/instrumentación , Polisacáridos Bacterianos/biosíntesis , Tensoactivos , Xanthomonas campestris/crecimiento & desarrollo
17.
Rev. argent. microbiol ; Rev. argent. microbiol;27(3): 146-55, 1995 Jul-Sep.
Artículo en Español | BINACIS | ID: bin-37214

RESUMEN

Xanthan production from Xanthomonas campestris was studied by a mechanically shaken fermentor. Influence of glucose concentration, aeration of culture media, rheology of broths and pH control was evaluated. Different aeration conditions based on variation of stirring rates were assayed. Substrate concentration was determined according to the Miller method, and polymer production was performed by the Cadmus method. The higher xanthan levels (i.e. 2.3


) were obtained at 750 rpm, with 1 v/v. min. In such conditions, viscosity ranges about 7000 cPoise and a low level of dissolved oxygen were detected in the culture medium. Xanthan production was influenced by the glucose concentration and the presence of amaranth within the culture medium. In the processes wherein an automatic control of pH was performed, the polymer concentration did not increase regarding to processes involving regular pH evolution.

18.
Rev Argent Microbiol ; 26(1): 9-20, 1994.
Artículo en Español | MEDLINE | ID: mdl-7938501

RESUMEN

The production of xantano from Xanthomonas campestris B-1459 was analyzed. The experiments were performed in shaked flasks at 250 rpm and 2.5 cm eccentricity. Using a base modified medium it was possible to achieve xantano concentration of 35 g/l in 72 h of process. The modified medium contained glucose as carbon source, and yeast extract, meat peptone, malt extract and amaranth meal as growth factors and nitrogen sources, in a KH2PO4/K2HPO4 buffer.


Asunto(s)
Medios de Cultivo/farmacología , Microbiología Industrial/métodos , Polisacáridos Bacterianos/biosíntesis , Xanthomonas campestris/metabolismo , Aerobiosis , Tampones (Química) , Grano Comestible , Fermentación , Frutas , Glucosa/farmacología , Nitrógeno/metabolismo , Plantas , Xanthomonas campestris/efectos de los fármacos
19.
Rev. argent. microbiol ; Rev. argent. microbiol;26(1): 9-20, 1994 Jan-Mar.
Artículo en Español | BINACIS | ID: bin-37567

RESUMEN

The production of xantano from Xanthomonas campestris B-1459 was analyzed. The experiments were performed in shaked flasks at 250 rpm and 2.5 cm eccentricity. Using a base modified medium it was possible to achieve xantano concentration of 35 g/l in 72 h of process. The modified medium contained glucose as carbon source, and yeast extract, meat peptone, malt extract and amaranth meal as growth factors and nitrogen sources, in a KH2PO4/K2HPO4 buffer.

20.
Rev. argent. microbiol ; Rev. argent. microbiol;26(1): 9-20, 1994 Jan-Mar.
Artículo en Español | LILACS-Express | LILACS, BINACIS | ID: biblio-1171615

RESUMEN

The production of xantano from Xanthomonas campestris B-1459 was analyzed. The experiments were performed in shaked flasks at 250 rpm and 2.5 cm eccentricity. Using a base modified medium it was possible to achieve xantano concentration of 35 g/l in 72 h of process. The modified medium contained glucose as carbon source, and yeast extract, meat peptone, malt extract and amaranth meal as growth factors and nitrogen sources, in a KH2PO4/K2HPO4 buffer.

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