title: Differential stress resistance and metabolic traits underlie coexistence in a sympatrically evolved bacterial population.
abstract: Following intermittent batch growth in Luria-Bertani (LB) broth for about 1000 generations, differentially evolved forms were found in a population of Escherichia coli cells. Studies on this population revealed the emergence of key polymorphisms, as evidenced by analysis of both whole genome sequences and transcription analysis. Here, we investigated the phenotypic nature of several key forms and found a remarkable (interactive) coexistence of forms which highlights the presence of different ecological roles pointing at a dichotomy in: (i) tolerance to environmental stresses and (ii) the capacity to utilize particular carbon sources such as galactose. Both forms differed from their common ancestor by different criteria. This apparent coexistence of two diverged forms points at the occurrence of niche partitioning as a consequence of dichotomous adaptive evolution. Remarkably, the two forms were shown to continue to coexist - in varying ratio's - in an experiment that cycled them through periods of nutrient feast (plentiful growth substrates) and famine (growth-restrictive - stress conditions). The results further indicated that the equilibrium of the coexistence was destroyed when one of the parameters was high tuned, jeopardizing the stability of the coexisting pair.
authors: Department of Microbial Ecology, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.
authors: Pilar Eliana
authors: PE
authors: Puentes-Téllez
authors: Jan Dirk
authors: JD
authors: van Elsas
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D004269:DNA, Bacterial / Q000235:genetics; D004463:Ecology; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D019143:Evolution, Molecular; D016680:Genome, Bacterial / Q000235:genetics*; D018869:Heat-Shock Response / Q000235:genetics*; D018384:Oxidative Stress / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics
chemical_list: C539345:BolA protein, E coli; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C479562:GadE protein, E coli; D014157:Transcription Factors