| abstract |
The invention relates to a nucleic acid sequence encoding an enantioselective amidase with an amino acid sequence, which amino acid sequence has at least 70% identity with SEQ ID NO: 2. The invention also relates to a prcoess for the fermentation, comprising a batch and a feed phase, of a microorganism in a fermentation medium, wherein the microorganism expresses a nucleic acid according to the invention and wherein between 0.5 and 50 mg/l_fermentation medium Zn 2+ is fed during the fermentation. The invention also relates to a process for the preparation of an enantiomerically enriched carboxylic acid and/or an enantiomerically enriched carboxylic acid amide, in which a mixture of the corresponding D- and L-carboxylic acid amides is contacted with an expression product according to the invention in the presence of between 0.01 mM and 100 mM Zn 2+ , whereby one of the enantiomers of the carboxylic acid amide is enantioselectively hydrolysed to form the corresponding enantiomerically enriched carboxylic acid, while the other enantiomer of the carboxylic acid amide remains unchanged. |