Modelling a nitrite-dependent anaerobic methane oxidation process: Parameters identification and model evaluation

He, Zhao; Cai, Chen; Geng, Sha; Lou, Liping; Xu, Xiangyang; Zheng, Ping; Hu, Baolan

doi:10.1016/j.biortech.2013.08.001

Cited by 85 publications

(38 citation statements)

References 22 publications

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“…The specific cell activity of the NC10 bacteria in the final marine denitrifying methanotrophic culture was 0.14 Ϯ 0.02 fmol CH 4 day Ϫ1 cell Ϫ1 , which corresponded to the previous measurements (0.09 to 0.34 fmol CH 4 day Ϫ1 cell Ϫ1 ) (8,26,38). Furthermore, the qPCR and FISH results showed that NC10 bacteria could grow in seawater media (20.5‰ of salinity) and that their apparent doubling times (38.7 to 48.9 days) were slightly longer than the doubling times previously observed in freshwater enrichment cultures (14 to 25 days) (3,29).…”

Section: Figsupporting

confidence: 86%

“…The denitrifying methanotroph-specific activity at various methane concentrations was plotted as shown in Fig. 5a, and the data were fitted by the Monod equation (29). Based on the best fitting in Fig.…”

Section: Figmentioning

confidence: 99%

“…Based on the best fitting in Fig. 5a, the apparent methane affinity coefficient (K CH4 ) of the denitrifying methanotrophs was estimated to be 9.8 Ϯ 2.2 M, which is in the range determined for freshwater denitrifying methanotrophic cultures (3 to 92 M) (29,30). The Monod kinetic equation was also applied to describe the relationship between the denitrifying methanotroph-specific activity and the nitrite concentration (Fig.…”

Section: Figmentioning

confidence: 99%

“…The energy advantage evident in equation 1 and equation 2 helps denitrifying methanotrophs synthesize more biomass and grow relatively quickly. The other advantage is that the halophilic denitrifying methanotrophs have a stronger affinity for methane (K CH4 ϭ 9.8 Ϯ 2.2 M) than the consortia that perform AOM coupled to sulfate reduction (K CH4 Ͼ 1.0 mM) (29). Furthermore, dissolved methane concentrations in coastal sediments are usually Ͻ2.0 mM (41), whereas those in the seabed can reach 5 to 15 mM at locations below the sulfate-methane transition zones (SMTZ) (42).…”

Section: Figmentioning

confidence: 99%

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Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

Geng

Cai

et al. 2015

Appl Environ Microbiol

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Anaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA and pmoA gene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescence in situ hybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ؎ 2.2 M for methane and 8.7 ؎ 1.5 M for nitrite.A naerobic oxidation of methane (AOM) occurs extensively in natural ecosystems and is a crucial biological sink in the global methane cycle that maintains the balance of greenhouse gas content in the atmosphere (1). To date, five electron acceptors that support AOM, including AOM coupled to sulfate reduction (2), nitrite reduction (3), nitrate reduction (4), iron reduction (5), and manganese reduction (5), have been discovered in natural settings. Moreover, on the basis of bioenergetic calculations, researchers have speculated that several other types of AOM (e.g., AOM coupled to perchlorate reduction, arsenate reduction, and selenate reduction) may exist in nature (6); however, these possible types have not yet been confirmed. In particular, AOM coupled to nitrite reduction has been a predominant research focus in the past several years. AOM coupled to nitrite reduction was also called nitrite-dependent anaerobic methane oxidation (ndamo) in previous reports. It has been demonstrated that AOM coupled to nitrite reduction is mediated by the bacterium "Candidatus Methylomirabilis oxyfera" (denitrifying methanotroph) (7), which is affiliated with the candidate NC10 phylum (8). This candidate division (NC10 phylum) was first defined by classification of environmental sequences retrieved from aquatic microbial formations in flooded caves (9). To date, our knowledge regarding the NC10 phylum has stemmed largely from research into "Ca. Methylomirabilis oxyfera" and "Ca. Methylomirabilis oxyfera"-like bacteria. According to the phylogenetic affiliations of 16S rRNA gene sequ...

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Section: Figsupporting

confidence: 86%

Section: Figmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

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Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

Geng

Cai

et al. 2015

Appl Environ Microbiol

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“…In phase III, the nitrite-reducing activities of cultures C1, C2, and C3 increased, and the average nitrite-reducing activities were 0.33, 0.32, and 0.34 mmol L −1 day −1 , respectively. The doubling time of n-damo bacteria in the cultures were estimated based on the rapid increase in the nitrite-reducing activities using the method reported by He et al (2013). The doubling times in cultures C1, C2, and C3 were estimated to be 3.2, 2.1, and 3.0 months from days 330-430, 330-430, and 250-430, respectively.…”

Section: Enrichment Of N-damo Bacteriamentioning

confidence: 99%

Effect of inoculum sources on the enrichment of nitrite-dependent anaerobic methane-oxidizing bacteria

Cai

Shen

et al. 2014

Appl Microbiol Biotechnol

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Nitrite-dependent anaerobic methane oxidation (n-damo) is a newly discovered biological process that couples anaerobic oxidation of methane (AOM) to nitrite reduction. In this study, three different inocula, methanogenic sludge, paddy soil, and freshwater sediment were used to enrich n-damo bacteria in three sequencing batch reactors (SBRs), and three n-damo enrichment cultures, C1, C2 and C3, were obtained, respectively. After 500 days of incubation, Methylomirabilis oxyfera-like bacteria and n-damo activities were observed in cultures C1, C2, and C3, and the specific activities were 0.8 ± 0.1, 1.4 ± 0.1, and 1.0 ± 0.1 μmol CH4 h(-1) g(-1) VSS, respectively. The copy numbers of 16S rRNA genes from cultures C1, C2, and C3 were 5.0 ± 0.4 × 10(8), 6.1 ± 0.1 × 10(9), and 1.0 ± 0.2 × 10(9) copies g(-1) dry weight, respectively. The results indicated that paddy soil is an excellent inoculum for n-damo bacterial enrichment. This work expanded the alternative source of n-damo inoculum and benefited the further research of n-damo process.

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Achieving complete nitrogen removal by coupling nitritation‐anammox and methane‐dependent denitrification: A model‐based study

Chen

Guo

Xie

et al. 2015

Biotech & Bioengineering

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The discovery of denitrifying anaerobic methane oxidation (DAMO) processes enables the complete nitrogen removal from wastewater by utilizing the methane produced on site from anaerobic digesters. This model-based study investigated the mechanisms and operational window for efficient nitrogen removal by coupling nitritation-anaerobic ammonium oxidation (Anammox) and methane-dependent denitrification in membrane biofilm reactors (MBfRs). A mathematical model was applied to describe the microbial interactions among Anammox bacteria, DAMO archaea, and DAMO bacteria. The model sufficiently described the batch experimental data from an MBfR containing an Anammox-DAMO biofilm with different feeding nitrogen compositions, which confirmed the validity of the model. The effects of process parameters on the system performance and microbial community structure could therefore be reliably evaluated. The impacts of nitritation produced NO2(-)/NH4(+) ratio, methane supply, biofilm thickness and total nitrogen (TN) surface loading were comprehensively investigated with the model. Results showed that the optimum NO2(-)/NH4(+) ratio produced from nitritation for the Anammox-DAMO biofilm system was around 1.0 in order to achieve the maximum TN removal (over 99.0%), independent on TN surface loading. The corresponding optimal methane supply increased while the associated methane utilization efficiency decreased with the increase of TN surface loading. The cooperation between DAMO organisms and Anammox bacteria played the key role in the TN removal. Based on these results, the proof-of-concept feasibility of a single-stage MBfR coupling nitritation-Anammox-DAMO for complete nitrogen removal was also tested through integrating the model with ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) processes whilst controlling the dissolved oxygen (DO) concentration in the simulated system. The maximum TN removal was found to be achieved at the bulk DO concentration of around 0.17 g m(-3) under the simulation conditions, with the AOB, Anammox bacteria and DAMO organisms coexisting in the biofilm.

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Modelling a nitrite-dependent anaerobic methane oxidation process: Parameters identification and model evaluation

Cited by 85 publications

References 22 publications

Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

Effect of inoculum sources on the enrichment of nitrite-dependent anaerobic methane-oxidizing bacteria

Achieving complete nitrogen removal by coupling nitritation‐anammox and methane‐dependent denitrification: A model‐based study

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