title: Evolutionary Consequence of a Trade-Off between Growth and Maintenance along with Ribosomal Damages.
abstract: Microorganisms in nature are constantly subjected to a limited availability of resources and experience repeated starvation and nutrition. Therefore, microbial life may evolve for both growth fitness and sustainability. By contrast, experimental evolution, as a powerful approach to investigate microbial evolutionary strategies, often targets the increased growth fitness in controlled, steady-state conditions. Here, we address evolutionary changes balanced between growth and maintenance while taking nutritional fluctuations into account. We performed a 290-day-long evolution experiment with a histidine-requiring Escherichia coli strain that encountered repeated histidine-rich and histidine-starved conditions. The cells that experienced seven rounds of starvation and re-feed grew more sustainably under prolonged starvation but dramatically lost growth fitness under rich conditions. The improved sustainability arose from the evolved capability to use a trace amount of histidine for cell propagation. The reduced growth rate was attributed to mutations genetically disturbing the translation machinery, that is, the ribosome, ultimately slowing protein translation. This study provides the experimental demonstration of slow growth accompanied by an enhanced affinity to resources as an evolutionary adaptation to oscillated environments and verifies that it is possible to evolve for reduced growth fitness. Growth economics favored for population increase under extreme resource limitations is most likely a common survival strategy adopted by natural microbes.
authors: Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.
authors: Bei-Wen
authors: BW
authors: Ying
authors: Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, 92093, United States of America.
authors: Tomoya
authors: T
authors: Honda
authors: Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Saburo
authors: S
authors: Tsuru
authors: Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Shigeto
authors: S
authors: Seno
authors: Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Hideo
authors: H
authors: Matsuda
authors: ERATO, JST, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Yasuaki
authors: Y
authors: Kazuta
authors: Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan; ERATO, JST, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Tetsuya
authors: T
authors: Yomo
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D001419:Bacteria / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018407:Bacterial Physiological Phenomena; D005075:Biological Evolution; D004777:Environment; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D016680:Genome, Bacterial / Q000502:physiology; D006639:Histidine / Q000378:metabolism; D009154:Mutation / Q000502:physiology; D014176:Protein Biosynthesis / Q000502:physiology; D012270:Ribosomes / Q000502:physiology*; D013217:Starvation
chemical_list: D006639:Histidine