Ratio of Electron Donor to Acceptor Influences Metabolic Specialization and Denitrification Dynamics in Pseudomonas aeruginosa in a Mixed Carbon Medium
Name
fmicb-12-711073.pdf
Description
Published version
Size
6.07 MB
Format
Adobe PDF
Checksum (MD5)
f9062b5a9281eeff1367d178e8ad6e4e
Author(s)
Zhang, Irene H.
Mullen, Susan
Ciccarese, Davide
Dumit, Diana
Martocello, Donald E.
Toyofuku, Masanori
Nomura, Nobuhiko
Smriga, Steven
Babbin, Andrew R.
Date Issued
September 2021
Journal
Frontiers in Microbiology
Publisher
Frontiers Media SA
Citation
Zhang Irene H. et al. "Ratio of Electron Donor to Acceptor Influences Metabolic Specialization and Denitrification Dynamics in Pseudomonas aeruginosa in a Mixed Carbon Medium." Frontiers in Microbiology 12 (September 2021): 711073. © 2021 Zhang et al.
Version
Final published version
Abstract
Denitrifying microbes sequentially reduce nitrate (NO₃⁻) to nitrite (NO₂⁻), NO, N₂O, and N₂ through enzymes encoded by nar, nir, nor, and nos. Some denitrifiers maintain the whole four-gene pathway, but others possess partial pathways. Partial denitrifiers may evolve through metabolic specialization whereas complete denitrifiers may adapt toward greater metabolic flexibility in nitrogen oxide (NO[subscript x]⁻) utilization. Both exist within natural environments, but we lack an understanding of selective pressures driving the evolution toward each lifestyle. Here we investigate differences in growth rate, growth yield, denitrification dynamics, and the extent of intermediate metabolite accumulation under varying nutrient conditions between the model complete denitrifier Pseudomonas aeruginosa and a community of engineered specialists with deletions in the denitrification genes nar or nir. Our results in a mixed carbon medium indicate a growth rate vs. yield tradeoff between complete and partial denitrifiers, which varies with total nutrient availability and ratios of organic carbon to NO[subscript x]⁻. We found that the cultures of both complete and partial denitrifiers accumulated nitrite and that the metabolic lifestyle coupled with nutrient conditions are responsible for the extent of nitrite accumulation.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology. Microbiology Graduate Program
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.3389/fmicb.2021.711073
