In:
PLOS ONE, Public Library of Science (PLoS), Vol. 16, No. 3 ( 2021-3-24), p. e0241960-
Abstract:
Diatoms are unicellular photosynthetic algae known to secrete organic matter that fuels secondary production in the ocean, though our knowledge of how their physiology impacts the composition of dissolved organic matter remains limited. Like all photosynthetic organisms, their use of light for energy and reducing power creates the challenge of avoiding cellular damage. To better understand the interplay between redox balance and organic matter secretion, we reconstructed a genome-scale metabolic model of Thalassiosira pseudonana strain CCMP 1335, a model for diatom molecular biology and physiology, with a 60-year history of studies. The model simulates the metabolic activities of 1,432 genes via a network of 2,792 metabolites produced through 6,079 reactions distributed across six subcellular compartments. Growth was simulated under different steady-state light conditions (5–200 μmol photons m -2 s -1 ) and in a batch culture progressing from exponential growth to nitrate-limitation and nitrogen-starvation. We used the model to examine the dissipation of reductants generated through light-dependent processes and found that when available, nitrate assimilation is an important means of dissipating reductants in the plastid; under nitrate-limiting conditions, sulfate assimilation plays a similar role. The use of either nitrate or sulfate uptake to balance redox reactions leads to the secretion of distinct organic nitrogen and sulfur compounds. Such compounds can be accessed by bacteria in the surface ocean. The model of the diatom Thalassiosira pseudonana provides a mechanistic explanation for the production of ecologically and climatologically relevant compounds that may serve as the basis for intricate, cross-kingdom microbial networks. Diatom metabolism has an important influence on global biogeochemistry; metabolic models of marine microorganisms link genes to ecosystems and may be key to integrating molecular data with models of ocean biogeochemistry.
Type of Medium:
Online Resource
ISSN:
1932-6203
DOI:
10.1371/journal.pone.0241960
DOI:
10.1371/journal.pone.0241960.g001
DOI:
10.1371/journal.pone.0241960.g002
DOI:
10.1371/journal.pone.0241960.g003
DOI:
10.1371/journal.pone.0241960.g004
DOI:
10.1371/journal.pone.0241960.g005
DOI:
10.1371/journal.pone.0241960.g006
DOI:
10.1371/journal.pone.0241960.g007
DOI:
10.1371/journal.pone.0241960.g008
DOI:
10.1371/journal.pone.0241960.s001
DOI:
10.1371/journal.pone.0241960.s002
DOI:
10.1371/journal.pone.0241960.s003
DOI:
10.1371/journal.pone.0241960.s004
DOI:
10.1371/journal.pone.0241960.s005
DOI:
10.1371/journal.pone.0241960.s006
DOI:
10.1371/journal.pone.0241960.s007
DOI:
10.1371/journal.pone.0241960.s008
DOI:
10.1371/journal.pone.0241960.s009
DOI:
10.1371/journal.pone.0241960.s010
DOI:
10.1371/journal.pone.0241960.s011
DOI:
10.1371/journal.pone.0241960.s012
DOI:
10.1371/journal.pone.0241960.s013
DOI:
10.1371/journal.pone.0241960.s014
DOI:
10.1371/journal.pone.0241960.s015
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2021
detail.hit.zdb_id:
2267670-3
Permalink