Journal article
Elimination of GlnKAmtB affects serine biosynthesis and improves growth and stress tolerance of Escherichia coli under nutrient-rich conditions
Instituto Nacional de Tecnología Agropecuaria1
Systems Environmental Microbiology, Research Groups, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark2
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark3
Research Groups, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark4
Nitrogen is a most important nutrient resource for Escherichia coli and other bacteria that harbor the glnKamtB operon, a high-affinity ammonium uptake system highly interconnected with cellular metabolism. Although this system confers an advantage to bacteria when growing under nitrogen-limiting conditions, little is known about the impact of these genes on microbial fitness under nutrient-rich conditions.
Here, the genetically tractable E. coli BW25113 strain and its glnKamtB-null mutant (JW0441) were used to analyze the impact of GlnK-AmtB on growth rates and oxidative stress tolerance. Strain JW0441 showed a shorter initial lag phase, higher growth rate, higher citrate synthase activity, higher oxidative stress tolerance and lower expression of serA than strain BW25113 under nutrient-rich conditions, suggesting a fitness cost to increase metabolic plasticity associated with serine metabolism.
The overexpression of serA in strain JW0441 resulted in a decreased growth rate and stress tolerance in nutrient-rich conditions similar to that of strain BW25113, suggesting that the negative influence on bacterial fitness imposed by GlnK-AmtB can be traced to the control of serine biosynthesis. Finally, we discuss the potential applications of glnKamtB mutants in bioproduction processes.
Language: | English |
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Year: | 2020 |
ISSN: | 15746968 and 03781097 |
Types: | Journal article |
DOI: | 10.1093/femsle/fnaa197 |
ORCIDs: | 0000-0001-5012-240X and Nikel, Pablo Ivan |
AmtB protein, E coli Cation Transport Proteins Escherichia coli Escherichia coli Proteins Industrial Microbiology Mutation Nucleotidyltransferases Operon PII Nitrogen Regulatory Proteins Serine ammonium uptake evolutionary innovation glnK protein, E coli growth rate lag phase oxidative stress