Dissecting of the AI-2/LuxS Mediated Growth Characteristics and Bacteriostatic Ability of Lactiplantibacillus plantarum SS-128 by Integration of Transcriptomics and Metabolomics

Abstract

<i>Lactiplantibacillus plantarum</i> could regulate certain physiological functions through the AI-2/LuxS-mediated quorum sensing (QS) system. To explore the regulation mechanism on the growth characteristics and bacteriostatic ability of <i>L. plantarum</i> SS-128, a <i>luxS</i> mutant was constructed by a two-step homologous recombination. Compared with Δ<i>luxS</i>/SS-128, the metabolites of SS-128 had stronger bacteriostatic ability. The combined analysis of transcriptomics and metabolomics data showed that SS-128 exhibited higher pyruvate metabolic efficiency and energy input, followed by higher LDH level and metabolite overflow compared to Δ<i>luxS</i>/SS-128, resulting in stronger bacteriostatic ability. The absence of <i>luxS</i> induces a regulatory pathway that burdens the cysteine cycle by quantitatively drawing off central metabolic intermediaries. To accommodate this mutations, Δ<i>luxS</i>/SS-128 exhibited lower metabolite overflow and abnormal proliferation. These results demonstrate that the growth characteristic and metabolism of <i>L. plantarum</i> SS-128 are mediated by the AI-2/LuxS QS system, which is a positive regulator involved in food safety. It would be helpful to investigate more bio-preservation control potential of <i>L. plantarum</i>, especially when applied in food industrial biotechnology.