title: Short-term differential adaptation to anaerobic stress via genomic mutations by Escherichia coli strains K-12 and B lacking alcohol dehydrogenase.
abstract: Microbial adaptations often occur via genomic mutations under adverse environmental conditions. This study used Escherichia coli ΔadhE cells as a model system to investigate adaptation to anaerobic conditions, which we then compared with the adaptive mechanisms of two closely related E. coli strains, K-12 and B. In contrast to K-12 ΔadhE cells, the E. coli B ΔadhE cells exhibited significantly delayed adaptive growth under anaerobic conditions. Adaptation by the K-12 and B strains mainly employed anaerobic lactate fermentation to restore cellular growth. Several mutations were identified in the pta or pflB genes of adapted K-12 cells, but mostly in the pta gene of the B strains. However, the types of mutation in the adapted K-12 and B strains were similar. Cellular viability was affected directly by severe redox imbalance in B ΔadhE cells, which also impaired their ability to adapt to anaerobic conditions. This study demonstrates that closely related microorganisms may undergo different adaptations under the same set of adverse conditions, which might be associated with the specific metabolic characteristics of each strain. This study provides new insights into short-term microbial adaptation to stressful conditions, which may reflect dynamic microbial population changes in nature.
authors.affiliation: Biosystems and Bioengineering Program, University of Science and Technology (UST) Daejeon, South Korea ; Infection and Immunity Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB) Daejeon, South Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Biosystems and Bioengineering Program, University of Science and Technology (UST) Daejeon, South Korea ; Korean Bioinformation Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB) Daejeon, South Korea.
authors.forename: Haeyoung
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Korean Bioinformation Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB) Daejeon, South Korea.
authors.forename: Seungwoo
authors.initials: S
authors.lastname: Hwang
authors.affiliation: Infection and Immunity Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB) Daejeon, South Korea.
authors.forename: Moo-Seung
authors.initials: MS
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Yong-Jik
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University Daegu, South Korea.
authors.forename: Dong-Woo
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Biosystems and Bioengineering Program, University of Science and Technology (UST) Daejeon, South Korea ; Infection and Immunity Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB) Daejeon, South Korea.
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Lee
keywords: adaptation; alcohol dehydrogenase; anaerobic condition; genomic mutation; pflB gene; pta gene; redox balance