Reutericyclin biosynthetic pathway

Reutericyclin production refers to the function of a gene cluster in *Lactobacillus reuteri* (and to some extent *L. plantarum* and other lactic acid bacteria) that synthesizes the antimicrobial compound **reutericyclin**, a low-molecular-weight antibiotic that is chemically a tetramic acid derivative[1][2][6]. The pathway consists of a nonribosomal peptide synthetase (RtcN), a polyketide synthase (RtcK), and associated accessory enzymes (RtcA, RtcB, RtcC), which together assemble and modify the molecule from primary metabolites[1]. Additional genes encode a phosphopantetheinyl transferase (RtcP), which activates the synthases[1]. The product, reutericyclin, has a selective bactericidal or bacteriostatic effect on Gram-positive bacteria by acting as a proton-ionophore—dissipating the transmembrane proton gradient of sensitive organisms[2][5][6]. Gram-negative bacteria and yeasts are resistant due to membrane properties[2][5][6]. The pathway is significant in food and feed fermentation and may contribute to microbiome modulation and food preservation benefits of probiotic *L. reuteri* strains[2][7].

Other names

Reutericyclin biosynthesisReutericyclin gene clusterRtc pathway