Integration of metabolomics and transcriptomics revealed the biosynthetic mechanism of anti-parasitic compounds in Salinivibrio proteolyticus strain YCSC6

Abstract

The fermentation broth of Salinivibrio proteolyticus strain YCSC6 shows potent anti-parasitic activity against Uronema marinum, with activity varying in each fermentation stage. To investigate the biosynthetic mechanism of anti-parasitic compounds in strain YCSC6, a comprehensive analysis of metabolomics and transcriptomics over four different time points (12, 24, 48, and 72 h) was performed. Metabolomics detected 17 943 metabolites with 1 129 known metabolites. A trend analysis of the known metabolites showed that 575 metabolites, including 69 polyketides, were continuously enhanced, being the potential source of anti-parasitic agents. In addition, 941 genes mapped to the same pathways of these metabolites, were screened through the association analysis of metabolites and genes. KEGG pathway enrichment of these genes showed 270 genes mapped to the biosynthesis of secondary metabolites and 192 genes mapped to the biosynthesis of antibiotics. This demonstrates the potent secondary metabolic capacity of strain YCSC6. Finally, a gene-metabolite correlation network was created based on the 575 continuously enhanced metabolites and 43 continuously up-regulated genes. This revealed 13 genes at the key position that mapped to a putative metabolic pathway associated with the biosynthesis of polyketides and caprylic acid, which contributes to the potent anti-parasitic activity of strain YCSC6. This comprehensive analysis of metabolomics and transcriptomics provides insights into the biosynthetic mechanisms of anti-parasitic compounds in strain YCSC6 and guides the exploitation of more anti-parasitic agents for aquaculture.