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Measuring bacterial adaptation dynamics at the single-cell level using a microfluidic chemostat and time-lapse fluorescence microscopy

TitleMeasuring bacterial adaptation dynamics at the single-cell level using a microfluidic chemostat and time-lapse fluorescence microscopy
Publication TypeJournal Article
Year of Publication2014
AuthorsLong, Z, Olliver, A, Brambilla, E, Sclavi, B, Cosentino Lagomarsino, M, Dorfman, KD
JournalAnalyst
Volume139
Pagination5254-5262
Abstract

We monitored the dynamics of cell dimensions and reporter GFP expression in individual E. coli cells growing in a microfluidic chemostat using time-lapse fluorescence microscopy. This combination of techniques allows us to study the dynamical responses of single bacterial cells to nutritional shift-down or shift-up for longer times and with more precision over the chemical environment than similar experiments performed on conventional agar pads. We observed two E. coli strains containing different promoter-reporter gene constructs and measured how both their cell dimensions and the GFP expression change after nutritional upshift and downshift. As expected{,} both strains have similar adaptation dynamics for cell size rearrangement. However{,} the strain with a ribosomal RNA promoter dependent reporter has a faster GFP production rate than the strain with a constitutive promoter reporter. As a result{,} the mean GFP concentration in the former strain changes rapidly with the nutritional shift{,} while that in the latter strain remains relatively stable. These findings characterize the present microfluidic chemostat as a versatile platform for measuring single-cell bacterial dynamics and physiological transitions.

URLhttp://dx.doi.org/10.1039/C4AN00877D
DOI10.1039/C4AN00877D