Humic substances as electron acceptors for microbial respiration

Lovley, Derek R.; Coates, John D.; Blunt-Harris, Elizabeth L.; Phillips, Elizabeth; Woodward, Joan C.

doi:10.1038/382445a0

Cited by 1,625 publications

(1,302 citation statements)

References 19 publications

Supporting

Mentioning

1,236

Contrasting

Unclassified

Order By: Relevance

“…It is relevant to note here that effective rate constants for Fe(III) oxide reduction as well as rates of FeRB growth may be affected significantly by the presence of Fe(III) chelators and/or soluble electron shuttling compounds (e.g., humic substances), both of which are known to accelerate enzymatic reduction of amorphous Fe(III) oxides (Lovley et al 1996Lovley and Woodward 1996). Recent studies suggest that such compounds are likely to be ubiquitous in natural sedimentary environments (Lovley 2000;Nevin and Lovley in press).…”

Section: Discussionmentioning

confidence: 99%

Kinetics of microbial Fe(III) oxide reduction in freshwater wetland sediments

Roden

Wetzel

2002

Limnology & Oceanography

158

112

View full text Add to dashboard Cite

The kinetics of microbial amorphous Fe(III) oxide reduction was investigated in sediments from a freshwater wetland in north central Alabama, USA. Fe(III) oxide concentrations decreased exponentially with time during anaerobic incubation of sediment slurries and homogenized surface sediments. Rates of organic carbon mineralization (⌺CO 2 ϩ CH 4 accumulation) did not change markedly during the course of Fe(III) oxide reduction, which indicated that the exponential decline in Fe(III) oxide concentration over time resulted primarily from Fe(III) limitation rather than a decrease in organic matter decay rate. Initial rates of Fe(III) oxide reduction were linearly correlated with initial Fe(III) oxide concentrations in experiments with mixtures of Fe(III)-rich and Fe(III)-depleted sediment slurries. Similar results were obtained in experiments with sediment from various depth intervals in the upper 3 cm of freshly collected cores. These findings provide explicit evidence that microbial Fe(III) oxide reduction rates are first order with respect to amorphous Fe(III) oxide concentration in the wetland sediment. The observed first-order relationship between Fe(III) oxide concentration and reduction rate is consistent with established models of surface area-controlled mineral transformation. An experiment in which Fe(III) oxide-rich sediment slurries were amended with different amounts of labile organic matter demonstrated a direct correlation between first-order Fe(III) reduction rate constants and initial rates of organic carbon mineralization. These results provide empirical support for existing approaches to modeling organic matter decay-dependent Fe(III) oxide reduction kinetics in sediments.

show abstract

Section: Discussionmentioning

confidence: 99%

Kinetics of microbial Fe(III) oxide reduction in freshwater wetland sediments

Roden

Wetzel

2002

Limnology & Oceanography

158

112

View full text Add to dashboard Cite

show abstract

“…DOM are redox-active natural organic compounds that contribute to biogeochemical redox reactions, including the transfer of electrons from microorganisms to poorly accessible mineral phases, such as Fe(III) oxides (Lovley et al, 1996;Bauer and Kappler, 2009), and from abiotic reductants to organic pollutants (e.g., halogenated hydrocarbons and nitroaromatics) (Kappler and Haderlein, 2003) or heavy metals (e.g., Cr(VI) and Hg(II)) (Zhilin et al, 2004;Zhang et al, 2011;Graham et al, 2012). In addition, DOM may act as redox buffer through accepting electrons from microbial respiration under anoxic condition, and donating electrons to nitrate, iron, and sulfate, which may significantly contribute to the decrease of methanogenesis (Cervantes et al, 2000;.…”

Section: Discussionmentioning

confidence: 99%

Electrochemical and spectroscopic characteristics of dissolved organic matter in a forest soil profile

Bi¹,

Lu²,

Yuan³

et al. 2013

Journal of Environmental Sciences

View full text Add to dashboard Cite

“…Microbial reduction of humics coupled to organic matter oxidation was first demonstrated by Lovley et al [28], and a number of bacteria capable of utilizing humics as TEA were isolated from natural wetlands [10]. More recently, Roden et al [40] reported microbial reduction of solid-phase humics by iron-reducing bacteria in wetlands.…”

Section: Introductionmentioning

confidence: 99%

Extracellular Quinones Affecting Methane Production and Methanogenic Community in Paddy Soil

Yang

et al. 2013

Microb Ecol

View full text Add to dashboard Cite

This study investigated the change of CH 4 production and methanogenic community in response to the presence of humic substances (humics) analogue, anthraquinone-2,6-disulfonate (AQDS). Anaerobic experiments used a Chinese paddy soil, and three concentration levels of 0.5, 5, and 20 mM AQDS were conducted. Results suggested that the effect of AQDS on methanogenesis was time-dependent and concentration-dependent. Twenty millimolars of AQDS was toxic for methanogenic activity almost for the entire experimental period. Slight inhibition of methanogenesis by AQDS respiration in the 0.5-and 5-mM AQDS-supplemented treatments occurred within the early period, while CH 4 accumulated throughout the later period was approximately five and ten times greater than that of the controls without AQDS, respectively. AQDS reduction coupling to acetate oxidization enriched Geobacter species, and the mcrA-targeted T-RFLP profiles revealed significant increase of Methanosarcina at the expense of Methanobacterium in the 0.5-and 5-mM AQDS treatments. The enriched syntrophic association between Geobacter and Methanosarcina was deduced to be an effective methanogenic pathway for converting acetate to CH 4 via direct interspecies electron transfer. This study implied the ecological importance of syntrophic interaction between methanogens and microorganisms enriched by anaerobic respiration of non-methanogenic terminal electron acceptors in paddy soils.

show abstract

Humic substances as electron acceptors for microbial respiration

Cited by 1,625 publications

References 19 publications

Kinetics of microbial Fe(III) oxide reduction in freshwater wetland sediments

Kinetics of microbial Fe(III) oxide reduction in freshwater wetland sediments

Electrochemical and spectroscopic characteristics of dissolved organic matter in a forest soil profile

Extracellular Quinones Affecting Methane Production and Methanogenic Community in Paddy Soil

Contact Info

Product

Resources

About