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Biomedical subjects

L Loperena

Publications and source records attributed to L Loperena.

5 recordsLinked to original sources
PubMed1992

Effect of aeration rate on the alcoholic fermentation of whey by Kluyveromyces fragilis.

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.

Animals↗
PubMed1982

[Iatrogenic disease in hemophilia and Von Willebrand's disease].

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.

Adult↗
PubMedDate not supplied

Study of Bacillus sp. culture conditions to promote production of unhairing proteases.

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.

Bacillus↗