Non-proteinogenic L-amino acids

Process for production of non-proteinogenic L-amino acids by direct fermentation of a microorganism strain known per se having a deregulated cysteine metabolism in a manner known per se, which comprises adding, during the fermentation, a nucleophilic compound to the fermentation batch in a manner such that this leads to the production of non-proteinogenic L-amino acids by the microorganism strain.