Single cell fitness of B. subtilis correlates with the ability to adapt to various stresses.

ABSTRACT: How cells dynamically respond to fluctuating environmental conditions depends on the architecture and noise of the underlying genetic circuits. Most work characterizing stress pathways in the model bacterium Bacillus subtilis has been performed on bulk cultures using ensemble assays. However, investigating the single cell response to stress is important since noise might generate significant phenotypic heterogeneity. Here, we study a single stress response (glucose starvation) to allow comparison of both population- and single cell data. Using a top-down approach, we investigate the transcriptional dynamics of various stress-related genes of B. subtilis in response to glucose starvation. Our data reveal that most stress-induced pathways respond highly heterogeneously to glucose starvation. Bacteria are commonly thought to exhibit phenotypic heterogeneity to increase their survival under changing environments by always having a subpopulation pre-adapted to adverse conditions. Interestingly, growth experiments with cultures that were either pre-adapted for glucose starvation or non-starved cells showed that non-starved cells demonstrate a significant growth advantage when challenged with a new stress. This suggests that once cells engage in a certain stress pathway they are only optimised for this specific condition. Hence it is important for the population to always maintain a 'naïve' subpopulation in case of fluctuating environments. Our data indicate the presence of performance-based selection, by which only cells with a sufficiently high-energy status or cellular fitness are able to diversify.

ORGANISM(S): Bacillus subtilis

PROVIDER: GSE33506 | GEO | 2012/07/01

SECONDARY ACCESSION(S): PRJNA148839

REPOSITORIES: GEO