Invasive Spartina anglica Greatly Alters the Rates and Pathways of Organic Carbon Oxidation and Associated Microbial Communities in an Intertidal Wetland of the Han River Estuary, Yellow Sea

Sung-Uk An,Hyeonji Lee,Bomina Kim,Hyeyoun Cho,Jung-Ho Hyun,Ui-Jung Jung

doi:10.3389/fmars.2020.00059

Abstract

This research was supported by the Korean Long-term Marine Ecological Researches (K-LTMER) funded by the Korean Ministry of Oceans and Fisheries, and by the Mid-career Scientist Research Program funded by the Korean Ministry of Science and ICT (No. 2018R1A2B2006340).

Highlights

Organic materials deposited in marine sediments are quickly mineralized by hydrolysis, fermentation, and a variety of processes that use different terminal-electron acceptors, including O2, NO3−, Mn(IV), Fe(III), and SO42− (Froelich et al, 1979; Canfield et al, 2005; Jørgensen, 2006)
Various physico-chemical and biological factors such as vegetation, bioturbation, freshwater runoff, tidal inundation, and anthropogenic activities are responsible for availability of the electron donors and acceptors for microbial metabolic activities (Alongi et al, 1999; Kristensen and Kostka, 2005; Hyun et al, 2009; An et al, 2019; Mok et al, 2019)
The rhizosphere appears to be a zone of intense re-oxidation of reduced solutes, such as Fe2+ and H2S, which results in a rapid regeneration of Fe(III) and sulfate for re-stimulating Fe(III) reduction (FeR) and sulfate reduction (SR), respectively (Hines et al, 1989; Gribsholt et al, 2003; Hyun et al, 2009; Luo et al, 2018)

Summary

Introduction

Organic materials deposited in marine sediments are quickly mineralized by hydrolysis, fermentation, and a variety of processes that use different terminal-electron acceptors, including O2, NO3−, Mn(IV), Fe(III), and SO42− (Froelich et al, 1979; Canfield et al, 2005; Jørgensen, 2006). In coastal areas where rapid iron cycling occurs, microbial Fe(III) reduction (FeR) becomes a significant anaerobic Corg oxidation pathway (Kostka et al, 2002a,b; Jensen et al, 2003; Hyun et al, 2007, 2009; Kristensen et al, 2011). In sediment that experiences rapid turnover of elements, the dynamics (i.e., production or consumption) of chemical constituents can hardly be interpreted by geochemical analyses alone (Jørgensen, 2006) In such conditions, the composition and diversity of microbial communities are among the most sensitive and rapid bio-indicators of environmental change because microorganisms with fast growth rates respond quickly to changes in environmental conditions (Lovell, 2005; Bertics and Ziebis, 2009; Choi et al, 2018). It is highly relevant to combine biogeochemical process analysis with microbiological information to confirm if certain Corg oxidation pathways occur or dominate under specific conditions, where the geochemical evidence is less informative in complex environments (Weiss et al, 2003; Dollhopf et al, 2005; Vandieken et al, 2012; Choi et al, 2018)

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