1. Simple enzymatic procedure for L-carnosine synthesis: whole-cell biocatalysis and efficient biocatalyst recycling.
- Author
-
Heyland J, Antweiler N, Lutz J, Heck T, Geueke B, Kohler HP, Blank LM, and Schmid A
- Subjects
- Bacteria enzymology, Biocatalysis, Peptide Hydrolases genetics, Peptide Hydrolases metabolism, Recombinant Proteins genetics, Recombinant Proteins metabolism, Yeasts enzymology, Bacteria metabolism, Biotechnology methods, Carnosine biosynthesis, Enzymes metabolism, Yeasts metabolism
- Abstract
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)., (© 2009 The Authors. Journal compilation © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.)
- Published
- 2010
- Full Text
- View/download PDF