Applied Microbiology and Biotechnology

, Volume 26, Issue 4, pp 305–312

Biotransformation of phenylpyruvic acid to l-phenylalanine using a strain of Pseudomonas fluorescens ATCC 11250 with high transaminase activity

  • Christopher Thomas Evans
  • Wendy Peterson
  • Christin Choma
  • Masanaru Misawa
Biotechnology

DOI: 10.1007/BF00256659

Cite this article as:
Evans, C.T., Peterson, W., Choma, C. et al. Appl Microbiol Biotechnol (1987) 26: 305. doi:10.1007/BF00256659

Abstract

The rate of l-phenylalanine production from phenylpyruvic acid by whole cells of Pseudomonas fluorescens strain ATCC 11250 was greater than 3 g·l-1 h-1. Synthesis of transaminase was constitutive but activity was greatest in medium containing d- or l- phenylalanine as sole nitrogen source. Maximum conversion was observed at 34–40° C and at alkaline pH, with over six times initial rate of conversion at pH 12 than at pH 5. The optimum catalyst (cell) concentration was between 10–20 mg ml-1 dry weight. The initial rate of conversion was directly proportional to phenylpyruvate concentration, up to 4%, but the conversion yield steadily decreased between 2% and 4% substrate concentration. The rate of conversion, as expected, increased as the concentration of glutamate increased. Whole cells were still capable of over 63% conversion after 40 days providing reactions were supplemented with pyridoxal phosphate. Immobilisation of cells in calcium alginate and operation of a packed bed bioreactor enabled the continuous production of l-phenylalanine in concentrations greater than 15 g·l-1 after 60 days operation.

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • Christopher Thomas Evans
    • 1
  • Wendy Peterson
    • 1
  • Christin Choma
    • 1
  • Masanaru Misawa
    • 1
  1. 1.Allelix Inc.MississaugaCanada
  2. 2.Genzyme (UK) Ltd.MaidstoneEngland