Escherichia coli metabolites promote Enterococcus avium growth by accelerating aerobic metabolic processes

Abstract Background & AimsCooperation between species in the same ecosystem is the core function of microbial communities. We found that in cocultures of Escherichia coli and Enterococcus avium isolated from the gut, the former promoted the growth of the latter. Hence, we investigated the mechanisms by which Escherichia coli promoted the growth of Enterococcus avium.MethodEnterococcus avium was cultured in growth medium supplemented with E. coli metabolites. The physical and chemical properties of the growth-promoting substances were determined by high-performance liquid chromatography. Transcriptomics and metabolomics analyses were performed to determine the possible mechanisms underlying the accelerated growth of Enterococcus avium.ResultsHigher concentrations of Escherichia coli metabolites accelerated the growth of Enterococcus avium in the logarithmic phase but not in the plateau phase. A group of small molecules with high polarity and thermal stability were found to promote the growth of Enterococcus avium. The Escherichia coli metabolites upregulated ribosome expression and oxidative phosphorylation and accelerated several aerobic metabolic processes in Enterococcus avium.ConclusionSome metabolites secreted by Escherichia coli may accelerate aerobic metabolism in Enterococcus avium, thereby increasing its growth rate. This study provides a meaningful insight for understanding the symbiosis between intestinal bacteria and its possible mechanisms.