Protein Variants | Comment | Organism |
---|---|---|
additional information | in a stirred tank reactor, during catalysis with immobilized cephalosporin C acylase (CCA), the microenvironmental pH drops to pH 7.2 in a nonbuffered system (with the pH maintained at pH 8.5 by adding alkali) due to the existence of diffusional resistance. The immobilized CCA only catalyzes only five batch reactions, suggesting that the sharp pH gradient impairs the enzyme stability. To buffer the protons produced in the hydrolysis of cephalosporin C by CCA, phosphate and bicarbonate buffers are introduced. When CCA is catalyzed with 0.1 M ammonium bicarbonate buffer, no obvious gradient between the bulk solution and intraparticle pH is detected, and the catalysis of 15 batch reactions is achieved. Accordingly, with 0.2 M ammonium bicarbonate buffer in a packed bed reactor, the immobilized CCA exhibits continuous catalysis with high conversion rates (over 95%) for 21 days. Reactions with ammonium bicarbonate buffer shows significant increases in the stability and catalytic efficiency of the immobilized CCA in different reactors compared to those in nonbuffered systems. Set-up for measurement of internal pH at different positions in the packed-bed reactor, overview | Pseudomonas sp. SE83 |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pseudomonas sp. SE83 | P15557 | - |
- |
Synonyms | Comment | Organism |
---|---|---|
AcyI | - |
Pseudomonas sp. SE83 |
acylase ACY 1 proenzyme | UniProt | Pseudomonas sp. SE83 |
CCA | - |
Pseudomonas sp. SE83 |
cephalosporin C acylase | - |
Pseudomonas sp. SE83 |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Pseudomonas sp. SE83 |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8.5 | - |
immobilized enzyme CCA | Pseudomonas sp. SE83 |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
the immobilized enzyme is very sensitive to changing pH during the reaction. Proton-forming bioconversion reactions, like the CCA reaction, in pakced-bed reactors, drastic decreases in pH during continuous catalysis have to be avoided | Pseudomonas sp. SE83 |