Klebsiella terrigena

The processes are based on whole bacterial cells. In the case of the pipecolic acid, an important building block for pharmaceutical chemistry, an S-selective amidase in Pseudomonas fluorescens cells, catalyses the reaction with high selectivity and the acid is obtained with an ee >99% (Scheme 6.27A). For the preparation of piperazine-2-carboxylic acid from the racemic amide a R- and a S-selective amidase are available. Utilising Klebsiella terrigena cells the S-enantiomer is prepared with 42% isolated yield and ee > 99%, while Burkholderia sp. cells catalyse the formation of the -enantiomer (ee=99%, Scheme 6.27 B). 

Lonza AG has reported on the use of enantioselective amidases for the resolution of piperazine-2-carboxamide and piperidine-2-carboxamide using whole cell biocatalysts from Klebsiella terrigena, Pseudomonas fluorescence and Burkholderia sp., the last containing an (R)-selective amidase (Scheme 12.2-7)[l 1. Furthermore, several amidases exhibiting high selectivities [either (Sj- or (R)-] towards 2-arylpropiona-... 

Organism A. oxydans, Arthrobacter oxydans A. xylosoxydans, Achromobacter xylosoxydans B. subtilis, Bacillus subtilis E. coli, Escherichia coli K. terrigena, Klebsiella terrigena M. neoau-rum, Mycobacter neoaurum O.antropii, Ochrobactrum antropii P. putida, Pseudomonas putida. 6-APA, 6-Aminopenicillanic acid... 

In Klebsiella terrigena and Bacillus subtilis, this enzyme is found within the acetoin cluster of genes. Interestingly, in Lactobacillus lactis, this gene is found within the gene cluster that encodes the enzymes of branched chain amino acid synthesis. This enzyme has different kinetic properties than the enzymes of K. terrigena and B. subtilis and may play a key role in acetolactate flux in L. lacHs (Goupil-Feuillerat et al. 1997). 

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