The pharmaceutical potential of ncAAs – in form of free amino acids, as well as a modification of peptides and proteins – has been reviewed recently (Blaskovich, 2016). Various examples demonstrate the potential of ncAA-modified linear AMPs. For example, the incorporation of proline analogs into proline-rich peptides increased their macrophage penetration potential and their activity against Listeria, Brucella, or methicillin-resistant S. aureus. Moreover, the stability of the corresponding AMPs against proteolytic degradation by trypsin has been improved (Kuriakose et al., 2013). First studies with nisin revealed a change in its antimicrobial activity if it was supplemented with either tryptophan- or proline analogs at different locations by force-feeding (Zhou et al., 2016b; Baumann et al., 2017). A drawback of this method is the global replacement of one canonical amino acid by the chosen ncAA in the whole proteome of the producing cell (Hoesl and Budisa, 2012; Zhou et al., 2016a; Baumann et al., 2017).