1. Comparison between the proteome of Escherichia coli single colony and during liquid culture.
- Author
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Fortuin, Suereta, Nel, Andrew J.M., Blackburn, Jonathan M., and Soares, Nelson C.
- Subjects
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ESCHERICHIA coli , *BACTERIAL cells , *CELL adhesion , *COLONIES - Abstract
Most bacterial proteomic studies done to date utilise bacterial cells harvested from liquid culture media. However, it is widely accepted that many important determinants associated with virulence and host cell adhesion are exclusively expressed during growth on solid media, as a crude mimic of true biofilms. Here, we compare the observed proteome of Escherichia coli K12 from isolated single colonies on solid media with those observed at different growth phases in liquid culture; i.e. early-log, mid-log, early-, mid- and late-stationary growth phases. A total of 2044 protein groups covering approximately 47% of the total proteome were identified across all studied conditions, including 1650 proteins identified from single colonies and 1679 proteins from liquid cultured cells. Label-free quantitative analysis revealed that the E. coli proteome of single colonies on a solid agar differs from that observed in liquid culture. Notably, the presence of proteins in the Suf-operon that are involved in iron mobilisation and swarming motility was associated exclusively with single colony profiles, whereas proteins involved in motility such as motA, motB, fliH, flip, fliD and fliJ were associated exclusively with cells grown in liquid culture. The data presented here provide a valuable resource for understanding the role of key proteins within microenvironments surrounding E. coli single colonies. To date, most proteomics studies have used E. coli cells harvested from liquid culture media even though many important determinants associated with virulence and host cell adhesion are exclusively expressed during growth on solid media. In this study, we compare the observed proteome of E. coli K12 from isolated single colonies on solid media with those observed at different growth phases in liquid culture; i.e. early-log, mid-log, early-, mid- and late-stationary growth phases. By using label-free quantitative analysis we demonstrate that the E. coli proteome of single colonies on a solid agar differs from that observed in liquid culture with an overlap of 68% of proteins between the two culture conditions. Our analysis further reveal the presence of proteins in the Suf-operon that are involved in iron mobilisation and swarming motility was associated exclusively with single colony profiles. While those proteins involved in motility such as motA, motB, fliH, flip, fliD and fliJ were associated exclusively with cells grown in liquid culture. By comparison to E. coli proteomic data available on liquid culture and solid media, this research represents a first effort to describe the differential expression of key E. coli proteins within microenvironments surrounding single colonies. Unlabelled Image • Label-free quantitative proteomics analysis of E. coli k12 from isolated single colonies on solid media and different growth phases in liquid culture; i.e. early-log, mid-log, early-, mid- and late-stationary growth phases. • Proteins from the Suf-operon exclusively identified in single colony E. coli profiles are involved in iron mobilisation and swarming motility. • Proteins involved in motility such as motA, motB, fliH, flip, fliD and fliJ were associated exclusively with E. coli cells grown in liquid culture. • A valuable resource for understanding the role of key proteins within microenvironments surrounding E. coli single colonies. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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