RESUMEN

In a search for microorganisms producing extracellular protease with unhairing activity, Bacillus subtilis IIQDB32 was isolated. Protease formation was significantly stimulated by glucose, tryptone, yeast extract, Ca(2+) and Mn(2+), but was repressed by ammonia and Fe(2+).

RESUMEN

The substitution of chemical depilatory agents in the leather industry by proteolytic enzymes produced by Bacillus species has an important economical and environmental impact. In previous assays, a Bacillus sp. showing a promising depilatory activity was isolated. In this paper, a culture medium that stimulated the synthesis and segregation of depilatory proteases, was selected. The influence of pH, oxygen supply rate (KLaC*), and inoculum age was evaluated on cell growth and protease production. Assays were carried out in lab bioreactors (1.2-1.4 l) at 37 degrees C. Five different media that differed in carbon and nitrogen sources were tested. pH ranged from 4.0 to 8.5. KLaC* varied between 40 and 470 mmol/lh. The best medium culture for protease production contained: nutrient broth (Britania) 8 g/l, yeast extract (Britania) 3 g/l, and mineral salts. Protease production was more effective at pH of 6.7, KLaC* of 360 mmol/lh, and inoculum age of 12 hours. These experimental conditions led to the following results: maximum proteolytic activity 2700 U/ml, overall volumetric protease productivity 300 u/ml-h, average specific growth rate 0.62 h-1, and average specific protease production rate 2.50 x 10(5) U/gh.

Asunto(s)

RESUMEN

The substitution of chemical depilatory agents in the leather industry by proteolytic enzymes produced by Bacillus species has an important economical and environmental impact. In previous assays, a Bacillus sp. showing a promising depilatory activity was isolated. In this paper, a culture medium that stimulated the synthesis and segregation of depilatory proteases, was selected. The influence of pH, oxygen supply rate (KLaC*), and inoculum age was evaluated on cell growth and protease production. Assays were carried out in lab bioreactors (1.2-1.4 l) at 37 degrees C. Five different media that differed in carbon and nitrogen sources were tested. pH ranged from 4.0 to 8.5. KLaC* varied between 40 and 470 mmol/lh. The best medium culture for protease production contained: nutrient broth (Britania) 8 g/l, yeast extract (Britania) 3 g/l, and mineral salts. Protease production was more effective at pH of 6.7, KLaC* of 360 mmol/lh, and inoculum age of 12 hours. These experimental conditions led to the following results: maximum proteolytic activity 2700 U/ml, overall volumetric protease productivity 300 u/ml-h, average specific growth rate 0.62 h-1, and average specific protease production rate 2.50 x 10(5) U/gh.

RESUMEN

The substitution of chemical depilatory agents in the leather industry by proteolytic enzymes produced by Bacillus species has an important economical and environmental impact. In previous assays, a Bacillus sp. showing a promising depilatory activity was isolated. In this paper, a culture medium that stimulated the synthesis and segregation of depilatory proteases, was selected. The influence of pH, oxygen supply rate (KLaC*), and inoculum age was evaluated on cell growth and protease production. Assays were carried out in lab bioreactors (1.2-1.4 l) at 37 degrees C. Five different media that differed in carbon and nitrogen sources were tested. pH ranged from 4.0 to 8.5. KLaC* varied between 40 and 470 mmol/lh. The best medium culture for protease production contained: nutrient broth (Britania) 8 g/l, yeast extract (Britania) 3 g/l, and mineral salts. Protease production was more effective at pH of 6.7, KLaC* of 360 mmol/lh, and inoculum age of 12 hours. These experimental conditions led to the following results: maximum proteolytic activity 2700 U/ml, overall volumetric protease productivity 300 u/ml-h, average specific growth rate 0.62 h-1, and average specific protease production rate 2.50 x 10(5) U/gh.

RESUMEN

In this paper, the influence of aeration rate on the alcoholic batch fermentation of whey by Kluyveromyces fragilis NRRL Y-2415 was investigated. Assays in 1.5-L fermentor using concentrated whey permeate containing 100 g/L of lactose were carried out at different oxygen supply rate (KLaC*) from 0 to 82 mmol/Lh. Optimum response was obtained at 14 mmol/Lh: ethanol production rate reached was 3.4 g/Lh yielding 0.46 g of product per gram of initial lactose. An increase of KLaC* from 0 to 14 mmol/Lh improved the ethanol production: maximum specific ethanol production rate (qpm) increased 3.3 times from 0.3 to 1.0 g/gh. For higher aeration levels, ethanol production diminished and biomass formation was stimulated. The declination of qpm and the increase of microns at higher aeration level lead to conclude the importance of a controlled oxygen supply in order to obtain the required balance between yeast biosynthetic needs and ethanol production.

Asunto(s)

Asunto(s)

RESUMEN

Se presenta el estudio familiar de una paciente con sangre incoagulable debido a ausencia congenita de fibrinogeno, asi como tambien la evolucion clinica de la nina. Su primera manifestacion hemorragica se observo en el periodo neonatal cuando presento sangrado de tres dias de duracion a la caida del cordon umbilical. Los eventos hemorragicos mas severos sufridos por esta paciente incluyeron una hemorragia epidural que requirio evacuacion con craniotomia parietal derecha y una hemorragia difusa del sistema nervioso central que determino su fallecimiento. En esta nina no se encontro fibrinogeno tiempo de sangrado prolongado, probablemente debido a que la agrecion plaquetaria requiere de la presencia de fibrinogeno

Asunto(s)

RESUMEN

From a group of 115 children with hereditary haemorrhagic disease, nine suffered avoidable accidents or incidents during their treatment, these nine patients represent 8.6% of the cases. The observed complications included a giant cervical hematoma and hemomediastinum after a puncture of the internal jugular vein; an encephalic lesion associated with descompressive craneotomy; a hemophilic pseudo cyst associated with inappropriate treatment of a tibial fracture; acute bleeding and shock after surgery for tonsillectomy and circumcision; subdural hygroma after a subdural puncture; giant hematoma and acute anemia secondary to a venous dissection; permanent dyslexia after inappropriate puncture; giant hematoma and acute anemia secondary to a venous dissection; permanent dyslexia after inappropriate management of intracranial bleeding; bleeding and acute anemia after surgical drainage of a prepucial hematoma and a joint hematoma of the left knee after synovectomy and application of a prosthesis.

Asunto(s)

RESUMEN

De una serie de 115 ninos con enfermedad hemorragica hereditaria, 9 sufrieron accidentes o incidentes previsibles durante su tratamiento, lo cual representa el 8.6% de los casos. La complicaciones observadas incluyeron un hematoma cervical gigante y hemomediastino despues de una punicion de yugular interna, una lesion encefalica extensa por hemorragia recidivante en relacion con craneotomia descomprensiva, un pseudoquiste hemofilico asociado a tratamiento inadecuado de una fractura, hemorragia aguda y estado de choque despues de amigdalectomia y circuncision, higroma subdural despues de puncion subdural, hematoma gigante y anemia aguda despues de una venodiseccion, dislexia permanente asociada a manejo inadecuado de una hemorragia intracraneana, anemia aguda por hemorragia despues de frenaje quirurgico de un hematoma prepucial, una complicacion hemorragica de sinovectomia y aplicacion de protesis de rodilla izquierda

Asunto(s)

Asunto(s)