Abstract
The Burkholderia cepecia 1003 screened by the authors' laboratory, which contained hydantoinase and N-carbamoylase activities, was used to prepare D-phenylalanine on a large scale. The dynamic parameters of the whole bioconversion process were measured, and the results showed that kr was 3.975×10-3 min-1, Km and rm of hydantoinase and N-carbamoylase were 16.7894 mmol ·L-1, 0.82688 mmol·L-1, 0.6127 mmol·L-1·min-1 and 4.828×10-4 mmol·L-1·min-1, respectively. Simulation was made including processes of dissolution of DL-BH, racemization of L-BH, hydrolysis of D-BH and hydrolysis of N-carbamyl phenylalanine. The significance of parameters in this model was investigated and these parameters were optimized. The results showed that the reaction rate of D-BH hydrolysis was higher than that of N-carbamyl phenylalanine hydrolysis, and the latter was the limiting step of the whole process. Promotion of N-carbamoylase activity was helpful to D-phenylalanine production. The rate of L-BH racemization was the main factor, which influenced the conversion of racemic BH.
Original language | English |
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Pages (from-to) | 764-769 |
Number of pages | 6 |
Journal | Huagong Xuebao/CIESC Journal |
Volume | 55 |
Issue number | 5 |
State | Published - May 2004 |
Keywords
- D-phenylalanine
- Dynamics
- Enzymatic catalysis
- Hydantoinase