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Beneficial Mutations from Evolution Experiments Increase Rates of Growth and Fermentation

Version 2 2024-06-05, 08:02
Version 1 2020-04-02, 11:18
journal contribution
posted on 2024-06-05, 08:02 authored by AL Sezmis, Martino Malerba, DJ Marshall, MJ McDonald
A major goal of evolutionary biology is to understand how beneficial mutations translate into increased fitness. Here, we study beneficial mutations that arise in experimental populations of yeast evolved in glucose-rich media. We find that fitness increases are caused by enhanced maximum growth rate (R) that come at the cost of reduced yield (K). We show that for some of these mutants, high R coincides with higher rates of ethanol secretion, suggesting that higher growth rates are due to an increased preference to utilize glucose through the fermentation pathway, instead of respiration. We examine the performance of mutants across gradients of glucose and nitrogen concentrations and show that the preference for fermentation over respiration is influenced by the availability of glucose and nitrogen. Overall, our data show that selection for high growth rates can lead to an enhanced Crabtree phenotype by the way of beneficial mutations that permit aerobic fermentation at a greater range of glucose concentrations.

History

Journal

Journal of Molecular Evolution

Volume

86

Pagination

111-117

Location

Germany

ISSN

0022-2844

eISSN

1432-1432

Language

English

Publication classification

C1.1 Refereed article in a scholarly journal

Issue

2

Publisher

SPRINGER