Heterologous expression and antimicrobial potential of class II bacteriocins.

Gut bacteria are known to produce bacteriocins to inhibit the growth of other bacteria. Consequently, bacteriocins have attracted increased attention as potential microbiome-editing tools. In this study we examine the inhibitory spectrum of 75 class II bacteriocins against 48 representative gut microbiota species. The bacteriocins were heterologously expressed in and evaluated and assays revealed 22 bacteriocins to inhibit at least one species and showed selective inhibition patterns against species implicated in certain disorders and diseases. Three bacteriocins were selected for assessment on mouse feces. Based on 16S rRNA sequencing of the cultivated feces we showed that the two bacteriocins: Actifencin (#13) and Bacteroidetocin A (#22) selectively inhibited the growth of and , respectively. The probiotic: Nissle 1917 was engineered to express these two bacteriocins in mice. However, the selective inhibitory patterns found in the and experiments could not be observed . Our study describes a methodology for heterologous high throughput bacteriocin expression and screening and elucidates the inhibitory patterns of class II bacteriocins on the gut microbiota.