Nitrogen and Phosphorus Metabolism of Methanogens

DeMoll, Edward

doi:10.1007/978-1-4615-2391-8_12

Cited by 7 publications

(4 citation statements)

References 47 publications

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“…Three mechanisms of ammonia assimilation in methanogens have been demonstrated (15). At low ammonia concentrations (Ͻ1 mM), cells use glutamine synthetase to catalyze ATPdependent synthesis of glutamine from ammonia and glutamate (36).…”

Section: Discussionmentioning

confidence: 99%

“…Activities of ammonia-assimilating enzymes. Each of the three methanogens tested contained detectable activities of each of the three ammonia-assimilating enzymes previously found in methanogens (15): glutamate dehydrogenase, glutamine synthetase, and alanine dehydrogenase. The activity levels of glutamine synthetase and alanine dehydrogenase were a Low and high ammonia refer to ammonia concentrations during growth.…”

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confidence: 86%

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Influence of pH on Ammonia Accumulation and Toxicity in Halophilic, Methylotrophic Methanogens

Kadam¹,

Boone²

1996

Appl Environ Microbiol

112

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We studied the effects of pH and ammonia concentration on the growth of three methanogens. These three halophilic, methylotrophic methanogens, Methanolobus bombayensis, Methanolobus taylorii, and Methanohalophilus zhilinaeae, grew at environmental pH ranges that overlapped with each other and spanned the pH range from 7.0 to 9.5. During growth they had reversed membrane pH gradients (⌬pH) at all pH values tested. The ⌬pH was in the range of ؊0.4 to ؊0.9 pH units, with the cytosol being more acidic than the environmental pH. Methanohalophilus zhilinaeae had the most negative ⌬pH (؊0.9 pH units). These negative pH gradients resulted in the accumulation of ammonium (NH 4 ؉), and when grown at the highest external ammonia concentrations that allowed good growth, cells had cytosolic NH 4 ؉ concentrations as high as 180 mM. The high concentrations of cytosolic NH 4 ؉ were accompanied by greater ⌬pH and lower concentrations of the major cytosolic cation K ؉ (compared with cells grown in medium with only 5 mM ammonia). Methanolobus bombayensis and Methanolobus taylorii were more sensitive to total external ammonia at higher external pH values, but the inhibitory concentration of un-ionized ammonia that resulted in a 50% reduction of the growth rate was about 2 to 5 mM, regardless of the pH. This is consistent with growth inhibition by ammonia in other bacteria. However, Methanohalophilus zhilinaeae was more resistant to un-ionized ammonia than any other known organism. It had a 50% inhibitory concentration for un-ionized ammonia of 13 mM at pH 8.5 and 45 mM at pH 9.5. We examined the effects of pH on three ammonia-assimilating activities (glutamine synthetase, glutamate dehydrogenase, and alanine dehydrogenase) in cell lysates and found that the pH ranges were consistent with the observed ranges of intracellular pH.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 86%

Influence of pH on Ammonia Accumulation and Toxicity in Halophilic, Methylotrophic Methanogens

Kadam¹,

Boone²

1996

Appl Environ Microbiol

112

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“…The loss of intracellular NH 3 by diffusion through the cytoplasmic membrane after previous permease-dependent consumption in the form of NH 4 + can lead to a decrease in proton motive force (Chen et al, 2008). However, NH 4 + is the main nitrogen source for most groups of methanogenic archaea (DeMoll, 1993), and the example of the communities from methane tanks and bioreactors has indicated that ammonium can have a negative impact on methanogenesis only at concentrations above 0.6 g L -1 (Yenigün and Demirel, 2013; Chen et al, Fischer et al, 2019). In the Pfennig's medium cultures (NH 4 Cl -0.33 g L -1 ), a key influence on the number and activity of methanogenic microorganisms is rather the availability of methanogenesis substrates than the increased concentration of NH 4 + .…”

Section: Discussionmentioning

confidence: 99%

The role of coastal accumulations of the Spirogyra spp. filamentous algae as a methane source in the littoral zone of Lake Baikal

Bukin

Pavlova

Kalmychkov

et al. 2020

LFWB

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Excessive input of nutrients is one of the main causes of large-scale blooms of benthic algae in the coastal zone of water bodies, which has significant deleterious effects on biodiversity, abundance, and biomass of benthic littoral community. The decay of massive coastal accumulations of benthic algae can lead to secondary pollution in the littoral zone as well as be a source of methane, the second most important greenhouse gas. We experimentally studied methane production during decomposition by native microbial community of algal biomass of the Spirogyra spp. coastal accumulation from Lake Baikal. Methanogenesis was recorded both in the absence of additionally introduced biogenic elements and under elevated concentrations of phosphates. Under mesophilic temperature conditions (24 ° C and 37 ° C), the methane yield was 0.005-0.006 m 3 CH 4 kg − 1 of the algal dry weight. Among the methanogens, we detected the members of the genera Methanobacterium and Methanosphaerula

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“…In the methanogenic Archaea, ammonia is a universal source of nitrogen. Some species can use certain organic nitrogen compounds as well, and some can fix dinitrogen (11). Methanococcus maripaludis grows well with ammonia or alanine (Ala), and can also grow diazotrophically (5,16,33).…”

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confidence: 99%

Function and Regulation of glnA in the Methanogenic Archaeon Methanococcus maripaludis

1999

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The glnA gene in the domains Bacteria andArchaea encodes glutamine synthetase, a universally distributed enzyme that functions in ammonia assimilation and glutamine synthesis. We investigated the regulation and function ofglnA in the methanogenic archaeon Methanococcus maripaludis. The deduced amino acid sequence of the gene demonstrated its membership in class GSI-α of glutamine synthetases. The gene appeared to be expressed as a monocistronic operon.glnA mRNA levels and specific activities of glutamine synthetase were regulated similarly by nitrogen. Three transcription start sites were identified, corresponding to two overlapping nitrogen-regulated promoters and one weaker constitutive promoter. An inverted repeat immediately upstream of the regulated transcription start sites mediated repression under noninducing conditions. Thus, mutations that altered the sequence of the inverted repeat resulted in derepression. The inverted repeat had sequence similarity with a repeat that we previously identified as the nif operator ofM. maripaludis, suggesting a common mechanism of nitrogen regulation. Efforts to produce a glnA null mutant failed, suggesting that glnA is an essential gene in M. maripaludis.

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Nitrogen and Phosphorus Metabolism of Methanogens

Cited by 7 publications

References 47 publications

Influence of pH on Ammonia Accumulation and Toxicity in Halophilic, Methylotrophic Methanogens

Influence of pH on Ammonia Accumulation and Toxicity in Halophilic, Methylotrophic Methanogens

The role of coastal accumulations of the Spirogyra spp. filamentous algae as a methane source in the littoral zone of Lake Baikal

Function and Regulation of glnA in the Methanogenic Archaeon Methanococcus maripaludis

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