Mathematical modeling and comparative metabolomics analyses of interactions between Lactiplantibacillus plantarum and Morganella morganii.

Morganella morganii is a spoilage microorganism in fish products that produces harmful biogenic amines (BAs). It has been discovered that Lactiplantibacillus plantarum His6 can inhibit the growth of this bacterium. The aim of this study was to quantitatively assess the inhibitory impact of the bioprotective culture Lpb. plantarum His6 on M. morganii YC16 in the matrix (fish and rice) using predictive microbiology models, and elucidate the interaction mechanism through untargeted metabolomics. The mathematical model results showed the inhibition effect of Lpb. plantarum His6 on M. morganii YC16 was dependent on temperature and inoculation concentration. In addition, the simultaneous growth of Lpb. plantarum His6 and M. morganii YC16 could be well simulated with the Lotka-Volterra model. Furthermore, significant decreased in histamine levels was observed in co-(1:3) at 25 °C. Finally, based on the metabolomics data, it was speculated that Lpb. plantarum His6 may enhance bacteriocin production while reducing the yield of glycerophospholipids and fatty acids associated with outer membrane formation, thereby inhibiting the growth of M. morganii YC16. These findings provide valuable insights into the interaction behavior and mechanism of Lpb. plantarum His6 and M. morganii YC16 in co-culture, facilitating the design of the biopreservation strategies for fish products.