Abstract
Analyzing the biochemical and physiological activities of food microbes using molecular and bioinformatics tools is important, offering profound insights into their safety, functional, and applicational roles in food. In this study, Lactiplantibacillus plantarum NMGL2, a well-documented beneficial lactic acid bacteria (LAB) strain, was investigated for its genomic, metabolic, and transcriptomic characteristics. Whole-genome sequencing revealed that this strain possesses a chromosome and two plasmids, with 3320 annotated genes, showcasing pathways involved in carbohydrate metabolism, stress adaptation, and bioactive compound synthesis. Growth studies under various nutritional conditions, including fructose, lactose, exogenous exopolysaccharide (EPS), and soy peptone, demonstrated that nitrogen source alteration significantly enhanced bacterial growth and EPS production. Transcriptomic analysis showed the addition of EPS and soy peptone resulted in similar regulatory patterns, suggesting shared modulation of metabolic pathways, although distinct gene regulation patterns were involved. In contrast, fructose and lactose primarily regulated carbohydrate metabolism without increasing EPS yield. Prophage gene clusters were consistently down-regulated across all experimental conditions, reflecting the strain's adaptive response. These findings highlight L. plantarum NMGL2's ability to dynamically adjust its metabolism and gene expression in response to environmental and nutritional changes, offering valuable insights for its application in functional foods and probiotics. These results also imply the potential of LAB strains in bioactive compound production and health-related applications through metabolic engineering.