Simple enzymatic procedure for l-carnosine synthesis: whole-cell biocatalysis and efficient biocatalyst recycling
Article first published online: 4 AUG 2009
© 2009 The Authors. Journal compilation © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd
Special Issue: Biocatalysis. Guest Editors: Karl-Erich Jaeger, Andreas Schmid and Manuel Ferrer
Volume 3, Issue 1, pages 74–83, January 2010
How to Cite
Heyland, J., Antweiler, N., Lutz, J., Heck, T., Geueke, B., Kohler, H.-P. E., Blank, L. M. and Schmid, A. (2010), Simple enzymatic procedure for l-carnosine synthesis: whole-cell biocatalysis and efficient biocatalyst recycling. Microbial Biotechnology, 3: 74–83. doi: 10.1111/j.1751-7915.2009.00143.x
- Issue published online: 20 DEC 2009
- Article first published online: 4 AUG 2009
- Received 29 May, 2009; revised 6 July, 2009; accepted 8 July, 2009.
β-Peptides and their derivates are usually stable to proteolysis and have an increased half-life compared with α-peptides. Recently, β-aminopeptidases were described as a new enzyme class that enabled the enzymatic degradation and formation of β-peptides. As an alternative to the existing chemical synthesis routes, the aim of the present work was to develop a whole-cell biocatalyst for the synthesis and production of β-peptides using this enzymatic activity. For the optimization of the reaction system we chose the commercially relevant β,α-dipeptide l-carnosine (β-alanine-l-histidine) as model product. We were able to show that different recombinant yeast and bacteria strains, which overexpress a β-peptidase, could be used directly as whole-cell biocatalysts for the synthesis of l-carnosine. By optimizing relevant reaction conditions for the best-performing recombinant Escherichia coli strain, such as pH and substrate concentrations, we obtained high l-carnosine yields of up to 71%. Long-time as well as biocatalyst recycling experiments indicated a high stability of the developed biocatalyst for at least five repeated batches. Application of the recombinant E. coli in a fed-batch process enabled the accumulation of l-carnosine to a concentration of 3.7 g l−1.