CH
Carmen Hogendoorn
info
Please Note
<p>This page displays the records of the person named above and is not linked to a unique person identifier. This record may need to be merged to a profile.</p>
4 records found
1
Journal article
(2026)
-
Rob A. Schmitz, Stijn H. Peeters, Huub J.M. Op den Camp, Theo A. van Alen, Anchelique Mets, Carmen Hogendoorn, Guylaine H.L. Nuijten, Carmen A. Iosif, Arjan Pol, Stefan Schouten, Mike S.M. Jetten
Acidophilic microorganisms thrive in environments where the external pH is orders of magnitude lower than their intracellular pH. Verrucomicrobial methanotrophs of the family Methylacidiphilaceae, including Methylacidiphilum and Methylacidimicrobium, inhabit extremely acidic geothermal environments and can grow at a pH < 1.0 and temperatures up to 65 °C. We analyzed and compared their membrane fatty acid compositions at pH 3.0 across strains with different temperature optima. Thermophilic Methylacidiphilum strains almost exclusively contain saturated fatty acids, while the mesophilic Methylacidimicrobium strains we studied incorporate 16–47% unsaturated fatty acids. Notably, the thermophile Methylacidiphilum fumariolicum SolV increases unsaturated fatty acid content in response to a 10 °C temperature decrease but not to a decrease in pH from 3.0 to 1.7. Genomic analysis revealed a conserved fatty acid biosynthesis pathway. Despite constitutive expression of predicted pH homeostasis genes, SolV did not upregulate them upon changing the pH from 3.0 to 1.7. However, genes involved in methane oxidation were strongly upregulated, suggesting a potential metabolic adaptation to extreme acidity.
...
Acidophilic microorganisms thrive in environments where the external pH is orders of magnitude lower than their intracellular pH. Verrucomicrobial methanotrophs of the family Methylacidiphilaceae, including Methylacidiphilum and Methylacidimicrobium, inhabit extremely acidic geothermal environments and can grow at a pH < 1.0 and temperatures up to 65 °C. We analyzed and compared their membrane fatty acid compositions at pH 3.0 across strains with different temperature optima. Thermophilic Methylacidiphilum strains almost exclusively contain saturated fatty acids, while the mesophilic Methylacidimicrobium strains we studied incorporate 16–47% unsaturated fatty acids. Notably, the thermophile Methylacidiphilum fumariolicum SolV increases unsaturated fatty acid content in response to a 10 °C temperature decrease but not to a decrease in pH from 3.0 to 1.7. Genomic analysis revealed a conserved fatty acid biosynthesis pathway. Despite constitutive expression of predicted pH homeostasis genes, SolV did not upregulate them upon changing the pH from 3.0 to 1.7. However, genes involved in methane oxidation were strongly upregulated, suggesting a potential metabolic adaptation to extreme acidity.
Journal article
(2024)
-
Changqing Liu, Rob A. Schmitz, Arjan Pol, Carmen Hogendoorn, Daniël Verhagen, Stijn H. Peeters, Theo A. van Alen, Geert Cremers, Rob A. Mesman, Huub J. M. Op den Camp
Terrestrial geothermal ecosystems are hostile habitats, characterized by large emissions of environmentally relevant gases such as CO2, CH4, H2S and H2. These conditions provide a niche for chemolithoautotrophic microorganisms. Methanotrophs of the phylum Verrucomicrobia, which inhabit these ecosystems, can utilize these gases and grow at pH levels below 1 and temperatures up to 65°C. In contrast, methanotrophs of the phylum Proteobacteria are primarily found in various moderate environments. Previously, novel verrucomicrobial methanotrophs were detected and isolated from the geothermal soil of the Favara Grande on the island of Pantelleria, Italy. The detection of pmoA genes, specific for verrucomicrobial and proteobacterial methanotrophs in this environment, and the partially overlapping pH and temperature growth ranges of these isolates suggest that these distinct phylogenetic groups could coexist in the environment. In this report, we present the isolation and characterization of a thermophilic and acid-tolerant gammaproteobacterial methanotroph (family Methylococcaceae) from the Favara Grande. This isolate grows at pH values ranging from 3.5 to 7.0 and temperatures from 35°C to 55°C, and diazotrophic growth was demonstrated. Its genome contains genes encoding particulate and soluble methane monooxygenases, XoxF- and MxaFI-type methanol dehydrogenases, and all enzymes of the Calvin cycle. For this novel genus and species, we propose the name ‘Candidatus Methylocalor cossyra’ CH1.
...
Terrestrial geothermal ecosystems are hostile habitats, characterized by large emissions of environmentally relevant gases such as CO2, CH4, H2S and H2. These conditions provide a niche for chemolithoautotrophic microorganisms. Methanotrophs of the phylum Verrucomicrobia, which inhabit these ecosystems, can utilize these gases and grow at pH levels below 1 and temperatures up to 65°C. In contrast, methanotrophs of the phylum Proteobacteria are primarily found in various moderate environments. Previously, novel verrucomicrobial methanotrophs were detected and isolated from the geothermal soil of the Favara Grande on the island of Pantelleria, Italy. The detection of pmoA genes, specific for verrucomicrobial and proteobacterial methanotrophs in this environment, and the partially overlapping pH and temperature growth ranges of these isolates suggest that these distinct phylogenetic groups could coexist in the environment. In this report, we present the isolation and characterization of a thermophilic and acid-tolerant gammaproteobacterial methanotroph (family Methylococcaceae) from the Favara Grande. This isolate grows at pH values ranging from 3.5 to 7.0 and temperatures from 35°C to 55°C, and diazotrophic growth was demonstrated. Its genome contains genes encoding particulate and soluble methane monooxygenases, XoxF- and MxaFI-type methanol dehydrogenases, and all enzymes of the Calvin cycle. For this novel genus and species, we propose the name ‘Candidatus Methylocalor cossyra’ CH1.
Journal article
(2020)
-
Rob Schmitz, Arjan Pol, Sepehr S. Mohammadi, Carmen Hogendoorn, Antonie H. Van Gelder, Mike S.M. Jetten, Lena J. Daumann, Huub J.M. op den Camp
The trace amounts (0.53 ppmv) of atmospheric hydrogen gas (H2) can be utilized by microorganisms to persist during dormancy. This process is catalyzed by certain Actinobacteria, Acidobacteria, and Chloroflexi, and is estimated to convert 75 × 1012 g H2 annually, which is half of the total atmospheric H2. This rapid atmospheric H2 turnover is hypothesized to be catalyzed by high-affinity [NiFe] hydrogenases. However, apparent high-affinity H2 oxidation has only been shown in whole cells, rather than for the purified enzyme. Here, we show that the membrane-associated hydrogenase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV possesses a high apparent affinity (Km(app) = 140 nM) for H2 and that methanotrophs can oxidize subatmospheric H2. Our findings add to the evidence that the group 1h [NiFe] hydrogenase is accountable for atmospheric H2 oxidation and that it therefore could be a strong controlling factor in the global H2 cycle. We show that the isolated enzyme possesses a lower affinity (Km = 300 nM) for H2 than the membrane-associated enzyme. Hence, the membrane association seems essential for a high affinity for H2. The enzyme is extremely thermostable and remains folded up to 95 °C. Strain SolV is the only known organism in which the group 1h [NiFe] hydrogenase is responsible for rapid growth on H2 as sole energy source as well as oxidation of subatmospheric H2. The ability to conserve energy from H2 could increase fitness of verrucomicrobial methanotrophs in geothermal ecosystems with varying CH4 fluxes. We propose that H2 oxidation can enhance growth of methanotrophs in aerated methane-driven ecosystems. Group 1h [NiFe] hydrogenases could therefore contribute to mitigation of global warming, since CH4 is an important and extremely potent greenhouse gas.
...
The trace amounts (0.53 ppmv) of atmospheric hydrogen gas (H2) can be utilized by microorganisms to persist during dormancy. This process is catalyzed by certain Actinobacteria, Acidobacteria, and Chloroflexi, and is estimated to convert 75 × 1012 g H2 annually, which is half of the total atmospheric H2. This rapid atmospheric H2 turnover is hypothesized to be catalyzed by high-affinity [NiFe] hydrogenases. However, apparent high-affinity H2 oxidation has only been shown in whole cells, rather than for the purified enzyme. Here, we show that the membrane-associated hydrogenase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV possesses a high apparent affinity (Km(app) = 140 nM) for H2 and that methanotrophs can oxidize subatmospheric H2. Our findings add to the evidence that the group 1h [NiFe] hydrogenase is accountable for atmospheric H2 oxidation and that it therefore could be a strong controlling factor in the global H2 cycle. We show that the isolated enzyme possesses a lower affinity (Km = 300 nM) for H2 than the membrane-associated enzyme. Hence, the membrane association seems essential for a high affinity for H2. The enzyme is extremely thermostable and remains folded up to 95 °C. Strain SolV is the only known organism in which the group 1h [NiFe] hydrogenase is responsible for rapid growth on H2 as sole energy source as well as oxidation of subatmospheric H2. The ability to conserve energy from H2 could increase fitness of verrucomicrobial methanotrophs in geothermal ecosystems with varying CH4 fluxes. We propose that H2 oxidation can enhance growth of methanotrophs in aerated methane-driven ecosystems. Group 1h [NiFe] hydrogenases could therefore contribute to mitigation of global warming, since CH4 is an important and extremely potent greenhouse gas.
Journal article
(2019)
-
Gerben Roelandt Stouten, Carmen Hogendoorn, Sieze Douwenga, Estelle Silvia Kilias, Gerard Muyzer, Robbert Kleerebezem
Exposing a microbial community to alternating absence and presence of carbon substrate in aerobic conditions is an effective strategy for enrichment of storage polymers (polyhydroxybutyrate, PHB) producing microorganisms. In this work we investigate to which extent intermediate storage polymer production is a temperature independent microbial competition determining factor. Eight parallel bioreactors were operated in the temperature range of 20–40 °C, but intermediate storage polymer production was only obtained at 25–35 °C. Besides PHB production and consumption, cell decay and subsequent cryptic growth on lysis products was found to determine process properties and the microbial community structure at all operational temperatures. At 40 °C decay processes cannot be overcome with additional energy from storage polymers, and fast-growing microorganisms dominate the system. At 20 °C, highly competitive communities with ambiguous storage properties were enriched. The results described here demonstrate that a rigorous experimental approach could aid in the understanding of competitive strategies in microbial communities.
...
Exposing a microbial community to alternating absence and presence of carbon substrate in aerobic conditions is an effective strategy for enrichment of storage polymers (polyhydroxybutyrate, PHB) producing microorganisms. In this work we investigate to which extent intermediate storage polymer production is a temperature independent microbial competition determining factor. Eight parallel bioreactors were operated in the temperature range of 20–40 °C, but intermediate storage polymer production was only obtained at 25–35 °C. Besides PHB production and consumption, cell decay and subsequent cryptic growth on lysis products was found to determine process properties and the microbial community structure at all operational temperatures. At 40 °C decay processes cannot be overcome with additional energy from storage polymers, and fast-growing microorganisms dominate the system. At 20 °C, highly competitive communities with ambiguous storage properties were enriched. The results described here demonstrate that a rigorous experimental approach could aid in the understanding of competitive strategies in microbial communities.