RESUMO
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.
Assuntos
Quimosina/biossíntese , Proteínas Fúngicas/biossíntese , Rhizomucor/enzimologia , Fermentação , Microbiologia Industrial , Rhizomucor/classificação , Rhizomucor/crescimento & desenvolvimento , Especificidade da EspécieRESUMO
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.
Assuntos
Técnicas Bacteriológicas/instrumentação , Medicago sativa/microbiologia , Polissacarídeos Bacterianos/biossíntese , Sinorhizobium/crescimento & desenvolvimento , Aerobiose , Meios de Cultura/metabolismo , Fermentação , Oxigênio/farmacologia , Sinorhizobium/efeitos dos fármacos , Sinorhizobium/metabolismo , Fatores de TempoRESUMO
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.
Assuntos
Argentina , Polissacarídeos Bacterianos , Sinorhizobium melilotiRESUMO
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)
Assuntos
Sinorhizobium meliloti , Polissacarídeos Bacterianos , ArgentinaRESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
Assuntos
alfa-Amilases , Corante Amaranto , Aspergillus niger , Corantes , Meios de Cultura , Indicadores e Reagentes , Proteínas Fúngicas/biossíntese , Aspergillus niger , FermentaçãoRESUMO
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)
Assuntos
Corante Amaranto/farmacologia , Aspergillus niger/efeitos dos fármacos , Meios de Cultura/química , Corantes/farmacologia , Proteínas Fúngicas/biossíntese , Indicadores e Reagentes/farmacologia , alfa-Amilases/biossíntese , Aspergillus niger/enzimologia , Aspergillus niger/crescimento & desenvolvimento , FermentaçãoRESUMO
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.
Assuntos
Corante Amaranto/farmacologia , Aspergillus niger/efeitos dos fármacos , Corantes/farmacologia , Meios de Cultura/química , Proteínas Fúngicas/biossíntese , Indicadores e Reagentes/farmacologia , alfa-Amilases/biossíntese , Aspergillus niger/enzimologia , Aspergillus niger/crescimento & desenvolvimento , FermentaçãoRESUMO
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.
RESUMO
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.
RESUMO
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.
Assuntos
Microbiologia Industrial/métodos , Polissacarídeos Bacterianos/isolamento & purificação , Xanthomonas campestris/metabolismo , Aerobiose , Técnicas Bacteriológicas/instrumentação , Meios de Cultura , Fermentação , Glucose , Microbiologia Industrial/instrumentação , Polissacarídeos Bacterianos/biossíntese , Tensoativos , Xanthomonas campestris/crescimento & desenvolvimentoRESUMO
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.
RESUMO
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.
Assuntos
Meios de Cultura/farmacologia , Microbiologia Industrial/métodos , Polissacarídeos Bacterianos/biossíntese , Xanthomonas campestris/metabolismo , Aerobiose , Soluções Tampão , Grão Comestível , Fermentação , Frutas , Glucose/farmacologia , Nitrogênio/metabolismo , Plantas , Xanthomonas campestris/efeitos dos fármacosRESUMO
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.
RESUMO
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.
RESUMO
The growth of Bradyrhizobium japonicum E-109 using cheese whey as carbon source was studied. The cheese whey was previously hydrolyzed by acid or enzymatic treatment with purified beta galactosidase or a crude extract from Kluyveromyces fragilis. The results obtained demonstrated that the use of the modified enzymatic hydrolyzed whey as carbon source allowed the growth of B. japonicum E-109 reaching a concentration of approximately 10(10) viable cells/ml. These results are considered of industrial value because the poluent power whey is greatly reduced.
Assuntos
Queijo , Meios de Cultura , Rhizobiaceae/crescimento & desenvolvimento , Saccharomycetales/crescimento & desenvolvimento , Animais , Meios de Cultura/química , Hidrólise , Lactose/metabolismo , Rhizobiaceae/enzimologia , Rhizobiaceae/metabolismo , Saccharomycetales/química , Saccharomycetales/metabolismo , Fatores de TempoRESUMO
The growth of Bradyrhizobium japonicum E-109 using cheese whey as carbon source was studied. The cheese whey was previously hydrolyzed by acid or enzymatic treatment with purified beta galactosidase or a crude extract from Kluyveromyces fragilis. The results obtained demonstrated that the use of the modified enzymatic hydrolyzed whey as carbon source allowed the growth of B. japonicum E-109 reaching a concentration of approximately 10(10) viable cells/ml. These results are considered of industrial value because the poluent power whey is greatly reduced.
RESUMO
The growth of Bradyrhizobium japonicum E-109 using cheese whey as carbon source was studied. The cheese whey was previously hydrolyzed by acid or enzymatic treatment with purified beta galactosidase or a crude extract from Kluyveromyces fragilis. The results obtained demonstrated that the use of the modified enzymatic hydrolyzed whey as carbon source allowed the growth of B. japonicum E-109 reaching a concentration of approximately 10(10) viable cells/ml. These results are considered of industrial value because the poluent power whey is greatly reduced.