Metabolic response of Brevibacterium epidermidis TRM83610 to NaCl stress and ectoine fermentation optimization

To elucidate the metabolic response of Brevibacterium epidermidis TRM83610 to NaCl stress and facilitate its industrial application, this study employed metabolomics techniques to analyze changes in intracellular metabolites, particularly compatible solutes, under NaCl concentrations of 0, 5%, 10%, and 15%. The ectoine production capacity was further evaluated and optimized using response surface methodology. Results indicated significant metabolic differences among sample groups, with detection of various secondary metabolites associated with antimicrobial activity and plant growth promotion. Six compatible solutes dominated by ectoine were identified. The metabolic response strategies to NaCl stress included osmostress resistance, oxidative stress resistance, and survival competition strategies. Through response surface optimization, ectoine yield reached 440.60 mg/L, representing a 6.22-fold increase over the initial yield of 70.75 mg/L, demonstrating substantial application potential for this strain. This research enriches our understanding of the metabolic profile of B. epidermidis TRM83610, preliminarily reveals its metabolic responses to NaCl stress, and provides a foundational basis for its further development and utilization. IMPORTANCEOur study reports, for the first time, the detection of N{varepsilon}-Acetyl-L-lysine in Brevibacterium epidermidis and the identification of Azetidomonamide A in a microorganism outside of Pseudomonas aeruginosa. It also represents the first elucidation of this strains metabolic response to NaCl stress. This research demonstrates the significant application and research value of B. epidermidis TRM 83610 and reveals that its strategy for coping with NaCl stress is multifaceted. This includes employing multi-pathway synergy to regulate multiple compatible solutes for osmostress resistance, producing antioxidant compounds for oxidative stress resistance, and secreting antimicrobial compounds as part of a survival competition strategy.