The environmental plasmid pQBR103 alters the single-cell Raman spectral profile of Pseudomonas fluorescens SBW25.

Although plasmids are ubiquitous amongst phytosphere pseudomonads, the advantage and costs of plasmids for the bacterial host remain unclear. The application of single-cell Raman spectral analysis to plasmid-bacterial systems under different environmental conditions offers a new means of determining the impact of plasmids on host cell physiology, metabolic status, and response to stress.