EVOLUTIONARY ADAPTATION TO TEMPERATURE. VII. EXTENSION OF THE UPPER THERMAL LIMIT OF ESCHERICHIA COLI
نویسندگان
چکیده
منابع مشابه
Evolutionary Adaptation to Temperature. Vii. Extension of the Upper Thermal Limit of Escherichia Coli.
What factors influence the ability of populations to adapt to extreme environments that lie outside their current tolerance limits? We investigated this question by exposing experimental populations of the bacterium Escherichia coli to lethally high temperatures. We asked: (1) whether we could obtain thermotolerant mutants with an extended upper thermal limit by this selective screen; (2) wheth...
متن کاملEvolutionary Adaptation to Temperature. I. Fitness Responses of Escherichia Coli to Changes in Its Thermal Environment.
We used bacteria to study experimentally the process of genetic adaptation to environmental temperature. Replicate lines of Escherichia coli, founded from a common ancestor, were propagated for 2,000 generations in 4 different thermal regimes as 4 experimental groups: constant 32, 37, or 42°C (thermal specialists), or a daily alternation between 32 and 42°C (32/42°C: thermal generalists). The a...
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Following an environmental change, the course of a population's adaptive evolution may be influenced by environmental factors, such as the degree of marginality of the new environment relative to the organism's potential range, and by genetic factors, including constraints that may have arisen during its past history. Experimental populations of bacteria were used to address these issues in the...
متن کاملEvolutionary Adaptation to Temperature. v. Adaptive Mechanisms and Correlated Responses in Experimental Lines of Escherichia Coli.
We previously demonstrated temperature-specific genetic adaptation in experimental lines of Escherichia coli. Six initially identical populations were propagated for 2000 generations under each of five regimes: constant 20°C, 32°C, 37°C, and 42°C, and a daily switch between 32°C and 42°C. Glucose was the sole carbon source in all cases. Here, we examine the physiological bases of adaptation to ...
متن کاملEvolutionary adaptation to temperature. IX. Preadaptation to novel stressful environments of Escherichia coli adapted to high temperature.
Stressful environments may be considered as those that reduce fitness, sometimes due in part to the increased metabolic expenditure required to sustain life. Direct adaptation to a stressor is expected to increase fitness and reduce maintenance metabolism, with the latter leading to increased biomass production. In this study, we test the general hypothesis that such adaptation to one stressor ...
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ژورنال
عنوان ژورنال: Evolution
سال: 1999
ISSN: 0014-3820,1558-5646
DOI: 10.1111/j.1558-5646.1999.tb03774.x