Short RNA products from E. coli cells and growth medium upon co-culturing with P. copri and R. rubrum

The study was aimed to find natural examples of such molecules that are excreted by bacteria of one species and can affect the growth of another microbe. For their identification, ten datasets were obtained, providing information on RNAs secreted by Escherichia coli grown either in monoculture or with Rhodospirilla rubrum or Prevotella copri. By classifying the identified RNAs into two categories, which can either be produced by both bacteria in a mixed population, or by only one, it was found that in the presence of competing conditions bacteria tend to secret RNAs with sequence similarity to the genome of co-cultured species. Based on this conclusion, several model molecules were selected for experimental verification and for the first time evidence was obtained confirming the participation of short secreted RNAs in intraspecies and interspecies communication in bacteria.