Quantifying Oxygen Management and Temperature and Light Dependencies of Nitrogen Fixation by Crocosphaera watsonii

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F19%3A00520329" target="_blank" >RIV/61388971:_____/19:00520329 - isvavai.cz</a>

Výsledek na webu

<a href="https://msphere.asm.org/content/4/6/e00531-19" target="_blank" >https://msphere.asm.org/content/4/6/e00531-19</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1128/mSphere.00531-19" target="_blank" >10.1128/mSphere.00531-19</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantifying Oxygen Management and Temperature and Light Dependencies of Nitrogen Fixation by Crocosphaera watsonii

Popis výsledku v původním jazyce

Crocosphaera is a major dinitrogen (N-2)-fixing microorganism, providing bioavailable nitrogen (N) to marine ecosystems. The N-2-fixing enzyme nitrogenase is deactivated by oxygen (O-2), which is abundant in marine environments. Using a cellular scale model of Crocosphaera sp. and laboratory data, we quantify the role of three O-2 management strategies by Crocosphaera sp. size adjustment, reduced O-2 diffusivity, and respiratory protection. Our model predicts that Crocosphaera cells increase their size under high O-2. Using transmission electron microscopy, we show that starch granules and thylakoid membranes are located near the cytoplasmic membranes, forming a barrier for O-2. The model indicates a critical role for respiration in protecting the rate of N-2 fixation. Moreover, the rise in respiration rates and the decline in ambient O-2 with temperature strengthen this mechanism in warmer water, providing a physiological rationale for the observed niche of Crocosphaera at temperatures exceeding 20 degrees C. Our new measurements of the sensitivity to light intensity show that the rate of N-2 fixation reaches saturation at a lower light intensity (similar to 100 mu mol m(-2) s(-1)) than photosynthesis and that both are similarly inhibited by light intensities of >500 mu mol m(-2) s(-1). This suggests an explanation for the maximum population of Crocosphaera occurring slightly below the ocean surface.nnIMPORTANCE Crocosphaera is one of the major N-2-fixing microorganisms in the open ocean. On a global scale, the process of N-2 fixation is important in balancing the N budget, but the factors governing the rate of N-2 fixation remain poorly resolved. Here, we combine a mechanistic model and both previous and present laboratory studies of Crocosphaera to quantify how chemical factors such as C, N, Fe, and O-2 and physical factors such as temperature and light affect N-2 fixation.

Název v anglickém jazyce

Quantifying Oxygen Management and Temperature and Light Dependencies of Nitrogen Fixation by Crocosphaera watsonii

Popis výsledku anglicky

Crocosphaera is a major dinitrogen (N-2)-fixing microorganism, providing bioavailable nitrogen (N) to marine ecosystems. The N-2-fixing enzyme nitrogenase is deactivated by oxygen (O-2), which is abundant in marine environments. Using a cellular scale model of Crocosphaera sp. and laboratory data, we quantify the role of three O-2 management strategies by Crocosphaera sp. size adjustment, reduced O-2 diffusivity, and respiratory protection. Our model predicts that Crocosphaera cells increase their size under high O-2. Using transmission electron microscopy, we show that starch granules and thylakoid membranes are located near the cytoplasmic membranes, forming a barrier for O-2. The model indicates a critical role for respiration in protecting the rate of N-2 fixation. Moreover, the rise in respiration rates and the decline in ambient O-2 with temperature strengthen this mechanism in warmer water, providing a physiological rationale for the observed niche of Crocosphaera at temperatures exceeding 20 degrees C. Our new measurements of the sensitivity to light intensity show that the rate of N-2 fixation reaches saturation at a lower light intensity (similar to 100 mu mol m(-2) s(-1)) than photosynthesis and that both are similarly inhibited by light intensities of >500 mu mol m(-2) s(-1). This suggests an explanation for the maximum population of Crocosphaera occurring slightly below the ocean surface.nnIMPORTANCE Crocosphaera is one of the major N-2-fixing microorganisms in the open ocean. On a global scale, the process of N-2 fixation is important in balancing the N budget, but the factors governing the rate of N-2 fixation remain poorly resolved. Here, we combine a mechanistic model and both previous and present laboratory studies of Crocosphaera to quantify how chemical factors such as C, N, Fe, and O-2 and physical factors such as temperature and light affect N-2 fixation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10606 - Microbiology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Science Signaling

ISSN

1945-0877

e-ISSN

—

Svazek periodika

4

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

e00531-19

Kód UT WoS článku

000506191700004

EID výsledku v databázi Scopus

2-s2.0-85076463593