Genome-scale metabolic model construction for Oceanimonas sp. GK1 and pathway analysis of salt stress

Currently, our understanding of the core functional microorganisms in high-salinity wastewater is still limited, and conventional sequencing techniques are insufficient for comprehensively characterizing the overall features of biological systems. Therefore, this study aims to elucidate and predict the behavior and adaptation pathways of the Oceanimonas species in high-salinity environments by constructing the first genome-scale metabolic model (GEM) of Oceanimonas, designated as iZJ929. The model was developed through iterative refinement using various carbon sources and includes 929 genes, 1510 metabolites, and 1699 reactions, achieving an accuracy of 99.5%, which is significantly higher than other metabolic network models. Utilizing this model, metabolic flux analysis under different salinity conditions revealed that at 3% NaCl, the activity of the tricarboxylic acid (TCA) cycle and the accumulation of ectoine reached their maximum levels, significantly promoting cell growth. Transcriptomic analysis further confirmed the upregulation of genes associated with compatible solute synthesis and carbon metabolism under salt stress, revealing the adaptive mechanisms of Oceanimonas sp. GK1 in response to salinity variations. This study provides new insights into the metabolic characteristics of microorganisms in changing environments and lays a theoretical foundation for their applications in industrial and environmental engineering.