Mechanisms underlying the enhancement of bacteriocin production in coculture of Pediococcus acidilactici CCFM18 and Bacillus cereus ATCC11778 as revealed by comparative metabolomics

• Coculture with B. cereus could increase the P. acidilactici ’s bacteriocin production. • Metabolomics revealed how coculture enhanced bacteriocin production. • New insights on bacteriocin-producing/sensitive strains interplay were revealed. This study constructed different microbial stress systems to investigate the influence of coculture of Pediococcus acidilactici CCFM18 with another strain on bacteriocin production. Among the tested strains, Bacillus cereus ATCC11778 showed the greatest induction effect on P. acidilactici ’s bacteriocin production, causing a maximum increase of 94.10% in bacteriocin yield compared with monoculture. Comparative metabolomics revealed the underlying induction mechanisms: P. acidilactici could produce bacteriocin that inhibits the growth of B. cereus , while suppressing its intracellular carbohydrate metabolism and synthesis of fatty acids that are essential for outer membrane formation. These events compromised the membrane integrity of B. cereus , causing the leakage of its intracellular metabolites like amino acids, purines, and pyrimidines, which were in turn utilized by P. acidilactici , thereby enhancing bacteriocin production through positive feedback regulation. This study provides new insights into the interspecies interactions between bacteriocin-producing and bacteriocin-susceptible strains, featuring competitive inhibition operating synergistically with metabolic resource recycling.