Evaluation of the differences between biofilm and planktonic Brucella abortus via metabolomics and proteomics

This study analyzed the difference between biofilm and planktonic Brucella abortus using metabolomics and proteomics. Brucella abortus was cultured in different media to induce Brucella abortus biofilm formation and planktonic cells, followed by metabolomics and proteomics analyses for these two samples. Significant differential metabolites were identified, followed by KEGG pathway analysis. Differentially expressed proteins were identified, followed by subcellular localization, GO annotation, and KEGG pathway enrichment. Additionally, a correlation analysis of metabolomics and proteomics was performed. Metabolomics analysis showed 7682 positive and 4433 negative metabolites, including 188 positive and 117 negative significant differential metabolites. These differential metabolites were enriched in fatty acid/unsaturated fatty acid biosynthesis and linoleic acid metabolism. Proteomics analysis revealed 1759 proteins, including 486 differentially expressed proteins, which were enriched in various metabolic and degradation-related pathways. Subcellular localization showed that 74.3% of the differential proteins were cytoplasmic proteins. Correlation analysis showed that 1-palmitoyl-2-oleoyl-phosphatidylglycerol had the most significant correlations with proteins, followed by cytosine. Both metabolites correlated with the protein Q57EI7 (RbsB-1, ribose ABC transporter). One common pathway, fatty acid biosynthesis, was identified by both proteomics and metabolomics analyses that involved the metabolites, oleic acid, and protein Q57DK3 (biotin carboxylase). There were metabolomic and proteomic differences between Brucella abortus biofilm and planktonic cells, and these results provide novel insights into the biofilm-forming process of Brucella abortus.