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Differential stress resistance and metabolic traits underlie coexistence in a sympatrically evolved bacterial population
Author(s) -
PuentesTéllez Pilar Eliana,
Elsas Jan Dirk
Publication year - 2015
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12551
Subject(s) - biology , niche , population , phenotype , genetics , evolutionary biology , escherichia coli , gene , ecology , demography , sociology
Summary Following intermittent batch growth in L uria– B ertani ( LB ) broth for about 1000 generations, differentially evolved forms were found in a population of E scherichia 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.