Growth and mortality of aerobic anoxygenic phototrophs in the North Pacific Subtropical Gyre

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F24%3A00585423" target="_blank" >RIV/61388971:_____/24:00585423 - isvavai.cz</a>

Result on the web

<a href="https://journals.asm.org/doi/10.1128/aem.00032-24" target="_blank" >https://journals.asm.org/doi/10.1128/aem.00032-24</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1128/aem.00032-24" target="_blank" >10.1128/aem.00032-24</a>

Result language

angličtina

Original language name

Growth and mortality of aerobic anoxygenic phototrophs in the North Pacific Subtropical Gyre

Original language description

Aerobic anoxygenic phototrophic (AAP) bacteria harvest light energy using bacteriochlorophyll-containing reaction centers to supplement their mostly heterotrophic metabolism. While their abundance and growth have been intensively studied in coastal environments, much less is known about their activity in oligotrophic open ocean regions. Therefore, we combined in situ sampling in the North Pacific Subtropical Gyre, north of O'ahu island, Hawaii, with two manipulation experiments. Infra-red epifluorescence microscopy documented that AAP bacteria represented approximately 2% of total bacteria in the euphotic zone with the maximum abundance in the upper 50 m. They conducted active photosynthetic electron transport with maximum rates up to 50 electrons per reaction center per second. The in situ decline of bacteriochlorophyll concentration over the daylight period, an estimate of loss rates due to predation, indicated that the AAP bacteria in the upper 50 m of the water column turned over at rates of 0.75-0.90 d-1. This corresponded well with the specific growth rate determined in dilution experiments where AAP bacteria grew at a rate 1.05 +/- 0.09 d-1. An amendment of inorganic nitrogen to obtain N:P = 32 resulted in a more than 10 times increase in AAP abundance over 6 days. The presented data document that AAP bacteria are an active part of the bacterioplankton community in the oligotrophic North Pacific Subtropical Gyre and that their growth was mostly controlled by nitrogen availability and grazing pressure. IMPORTANCE Marine bacteria represent a complex assembly of species with different physiology, metabolism, and substrate preferences. We focus on a specific functional group of marine bacteria called aerobic anoxygenic phototrophs. These photoheterotrophic organisms require organic carbon substrates for growth, but they can also supplement their metabolic needs with light energy captured by bacteriochlorophyll. These bacteria have been intensively studied in coastal regions, but rather less is known about their distribution, growth, and mortality in the oligotrophic open ocean. Therefore, we conducted a suite of measurements in the North Pacific Subtropical Gyre to determine the distribution of these organisms in the water column and their growth and mortality rates. A nutrient amendment experiment showed that aerobic anoxygenic phototrophs were limited by inorganic nitrogen. Despite this, they grew more rapidly than average heterotrophic bacteria, but their growth was balanced by intense grazing pressure.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10606 - Microbiology

Project

<a href="/en/project/GX19-28778X" target="_blank" >GX19-28778X: Phototrophic Gemmatimonadetes (PhotoGemm+)</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Applied and Environmental Microbiology

ISSN

0099-2240

e-ISSN

1098-5336

Volume of the periodical

90

Issue of the periodical within the volume

4

Country of publishing house

US - UNITED STATES

Number of pages

11

Pages from-to

e0003224

UT code for WoS article

001193248200001

EID of the result in the Scopus database

2-s2.0-85190268827