Evidence map›Paper›PMID 40454557›Full record

ArticleThe ISME journal2025

Oxygen isotope fractionation during anaerobic ammonium oxidation by the marine representative Candidatus Scalindua sp.

Kanae Kobayashi, Kazuya Nishina, Keitaro Fukushima, Yuji Onishi, Akiko Makabe, Mamoru Oshiki, Keisuke Koba, Satoshi Okabe

Abstract read
In one paragraph

Article in The ISME journal, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Kanae KobayashiDivision of Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
Kazuya NishinaBiogeochemical Cycle Modeling and Analysis Section, Earth System Division, National Institute for Environmental Studies, Onogawa, Tsukuba 305-8506, Japan.
Keitaro FukushimaCenter for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan.
Yuji OnishiCenter for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan.
Akiko MakabeInstitute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka 237-0061, Japan.
Mamoru OshikiDivision of Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
Keisuke KobaCenter for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan.
Satoshi OkabeDivision of Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.

Funding

Promotion of Science KAKENHI 18 J20742
6 · The paper itself

Abstract

Analysing the nitrogen (15ε) and oxygen (18ε) isotope effects of anaerobic ammonium oxidation (anammox) is essential for accurately assessing its potential contribution to fixed-N losses in the ocean, yet the 18ε of anammox remains unexplored. Here, we determined the previously unexplored 18ε of anammox using a highly enriched culture of the marine anammox species "Ca. Scalindua sp". Because Scalindua significantly accelerated oxygen isotope exchange between NO2- and H2O, we introduced a new rate constant for anammox-mediated oxygen isotope exchange (keq, AMX = 8.44 ~ 13.56 × 10-2 h-1), which is substantially faster than abiotic oxygen isotope exchange (keq, abio = 1.13 × 10-2 h-1), into a numerical model to estimate the 18ε during anammox. Based on our experimental results, we successfully determined the 18ε associated with: (1) conversion of NO2- to N2 (18εNO2- → N2 = 10.6 ~ 16.1‰), (2) NO2- oxidation to NO3- (18εNO2- → NO3- = -2.9 ~ -11.0‰, inverse fractionation), (3) incorporation of oxygen from water during NO2- oxidation to NO3- (18εH2O = 16.4 ~ 19.2‰). Our study underscores the possibility that unique anammox oxygen isotope signals may be masked due to substantial anammox-mediated oxygen isotope exchange between NO2- and H2O. Therefore, careful consideration is required when utilizing δ18ONO3- and δ18ONO2- as geochemical markers to assess the potential contribution of anammox to fixed-N losses in the ocean.

Indexed as

Ammonium CompoundsOxygen IsotopesAnaerobiosisNitrogenNitrogen IsotopesOxidation-ReductionSeawaterAmmonium CompoundsNitrogenNitrogen IsotopesOxygen Isotopesanammoxkinetic oxygen isotope effectoxygen isotope exchange between NO2− and H2OScalindua sp

Identifiers

PMID40454557
PMCPMC12203076

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.