These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Influence of mass transfer limitations on the enzymatic synthesis of beta-lactam antibiotics catalyzed by penicillin G acylase immobilized on glioxil-agarose.
    Author: Gonçalves LR, Ferreira AL, Fernandez-Lafuente R, Guisan JM, Giordano RC, Giordano RL.
    Journal: Bioprocess Biosyst Eng; 2008 Aug; 31(5):411-8. PubMed ID: 18040724.
    Abstract:
    Mass transfer effects were investigated for the synthesis of ampicillin and amoxicillin, at pH 6.5 and 25 degrees C, catalyzed by penicillin G acylase immobilized on agarose. The influence of external mass transfer was analysed using different stirring rates, ranging form 200 to 800 rpm. Above 400 rpm, the film resistance may be neglected. Intra-particle diffusion limitation was investigated using biocatalysts prepared with different enzyme loads and agarose with different mean pore diameters. When agarose with 6, 8 and 10% of crosslinking were used, for the same enzyme load, substrates and products concentration profiles presented no expressive differences, suggesting pore diameter is not important parameter. An increase on enzyme load showed that when more than 90 IU of enzyme activity were used per mL of support, the system was influenced by intra-particle mass transfer. A reactive-diffusive model was used to estimate effective diffusivities of substrates and products.
    [Abstract] [Full Text] [Related] [New Search]