The study aims to describe transcriptional patterns of single bacterial strains concerning their niche breadths along a salinity gradient. The niche breadth allows classifying organisms along the generalist-specialist continuum where generalist species are species with a broad niche, whose fitness is distributed evenly across multiple environments. In contrast, specialists are species with a narrow niche whose fitness is restricted to a few environments. We determined the niche breadth of 11 bacterial strains based on their tolerance against salinity stress to test the hypothesis that generalist species exposed to changing salinity exhibit higher transcriptional regulation of genes involved in the resistance against salinity compared to specialist strains. In contrast, we expected that genes involved in core cellular functions such as biomass production will be less regulated in generalists compared to specialists.