Simple enzymatic procedure for L-carnosine synthesis: whole-cell biocatalysis and efficient biocatalyst recycling

Microb Biotechnol. 2010 Jan;3(1):74-83. doi: 10.1111/j.1751-7915.2009.00143.x. Epub 2009 Aug 4.


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).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / enzymology
  • Bacteria / metabolism*
  • Biocatalysis
  • Biotechnology / methods*
  • Carnosine / biosynthesis*
  • Enzymes / metabolism*
  • Peptide Hydrolases / genetics
  • Peptide Hydrolases / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Yeasts / enzymology
  • Yeasts / metabolism*


  • Enzymes
  • Recombinant Proteins
  • Carnosine
  • Peptide Hydrolases