Biological chlorine cycling in the Arctic Coastal Plain

Biological chlorine cycling in the Arctic Coastal Plain This study explores biological chlorine cycling in coastal Arctic wet tundra soils. While many previous chlorine-cycling studies have focused on contaminated environments, it is now recognized that chlorine can cycle naturally between inorganic and organic forms in soils. However, these pathways have not previously been described for an Arctic ecosystem. We measured soil organic and inorganic Cl pools, characterized soils and plant tissues with chlorine K-edge X-ray absorption near-edge spectroscopy (Cl-XANES), measured dechlorination rates in laboratory incubations, and analyzed metagenomes and 16S rRNA genes along a chronosequence of revegetated drained lake basins. Concentrations of soil organic chlorinated compounds (Clorg) were correlated with organic matter content, with a steeper slope in older soils. The concentration and chemical diversity of Clorg increased with soil development, with Clorg in younger soils more closely resembling that of vegetation, and older soils having more complex and variable Cl-XANES signatures. Plant Clorg concentrations were higher than previously published values, and can account for the rapid accumulation of Clorg in soils. The high rates of Clorg input from plants also implies that soil Clorg pools turn over many times during soil development. Metagenomic analyses revealed putative genes for synthesis (haloperoxidases, halogenases) and breakdown (reductive dehalogenases, halo-acid dehalogenases) of Clorg, originating from diverse microbial genomes. Many genome sequences with close similarity to known organohalide respirers (e.g. Dehalococcoides) were identified, and laboratory incubations demonstrated microbial organohalide respiration in vitro. This study provides multiple lines of evidence for a complex and dynamic chlorine cycle in an Arctic tundra ecosystem. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Biogeochemistry Springer Journals

Biological chlorine cycling in the Arctic Coastal Plain

Loading next page...
 
/lp/springer_journal/biological-chlorine-cycling-in-the-arctic-coastal-plain-xEasdmKoES
Publisher
Springer International Publishing
Copyright
Copyright © 2017 by Springer International Publishing AG
Subject
Earth Sciences; Biogeosciences; Ecosystems; Environmental Chemistry; Life Sciences, general
ISSN
0168-2563
eISSN
1573-515X
D.O.I.
10.1007/s10533-017-0359-0
Publisher site
See Article on Publisher Site

Abstract

This study explores biological chlorine cycling in coastal Arctic wet tundra soils. While many previous chlorine-cycling studies have focused on contaminated environments, it is now recognized that chlorine can cycle naturally between inorganic and organic forms in soils. However, these pathways have not previously been described for an Arctic ecosystem. We measured soil organic and inorganic Cl pools, characterized soils and plant tissues with chlorine K-edge X-ray absorption near-edge spectroscopy (Cl-XANES), measured dechlorination rates in laboratory incubations, and analyzed metagenomes and 16S rRNA genes along a chronosequence of revegetated drained lake basins. Concentrations of soil organic chlorinated compounds (Clorg) were correlated with organic matter content, with a steeper slope in older soils. The concentration and chemical diversity of Clorg increased with soil development, with Clorg in younger soils more closely resembling that of vegetation, and older soils having more complex and variable Cl-XANES signatures. Plant Clorg concentrations were higher than previously published values, and can account for the rapid accumulation of Clorg in soils. The high rates of Clorg input from plants also implies that soil Clorg pools turn over many times during soil development. Metagenomic analyses revealed putative genes for synthesis (haloperoxidases, halogenases) and breakdown (reductive dehalogenases, halo-acid dehalogenases) of Clorg, originating from diverse microbial genomes. Many genome sequences with close similarity to known organohalide respirers (e.g. Dehalococcoides) were identified, and laboratory incubations demonstrated microbial organohalide respiration in vitro. This study provides multiple lines of evidence for a complex and dynamic chlorine cycle in an Arctic tundra ecosystem.

Journal

BiogeochemistrySpringer Journals

Published: Jul 7, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off