The role of soil pH on soil carbonic anhydrase activity
Carbonic anhydrases (CAs) are metalloenzymes present in plants and microorganisms that catalyse the interconversion of CO<sub>2</sub> and water to bicarbonate and protons. Because oxygen isotopes are also exchanged during this reaction, the presence of CA also modifies the contributio...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-01-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/15/597/2018/bg-15-597-2018.pdf |
| _version_ | 1818359037388914688 |
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| author | J. Sauze S. P. Jones L. Wingate S. Wohl J. Ogée |
| author_facet | J. Sauze S. P. Jones L. Wingate S. Wohl J. Ogée |
| author_sort | J. Sauze |
| collection | DOAJ |
| description | Carbonic anhydrases (CAs) are metalloenzymes present in
plants and microorganisms that catalyse the interconversion of CO<sub>2</sub> and
water to bicarbonate and protons. Because oxygen isotopes are also exchanged
during this reaction, the presence of CA also modifies the contribution of
soil and plant CO<sup>18</sup>O fluxes to the global budget of atmospheric
CO<sup>18</sup>O. The oxygen isotope signatures (<i>δ</i><sup>18</sup>O) of these
fluxes differ as leaf water pools are usually more enriched than soil water
pools, and this difference is used to partition the net CO<sub>2</sub> flux over
land into soil respiration and plant photosynthesis. Nonetheless, the use of
atmospheric CO<sup>18</sup>O as a tracer of land surface CO<sub>2</sub> fluxes requires
a good knowledge of soil CA activity. Previous studies have shown that
significant differences in soil CA activity are found in different biomes
and seasons, but our understanding of the environmental and ecological
drivers responsible for the spatial and temporal patterns observed in soil
CA activity is still limited. One factor that has been overlooked so far is
pH. Soil pH is known to strongly influence microbial community composition,
richness and diversity in addition to governing the speciation of CO<sub>2</sub>
between the different carbonate forms. In this study we investigated the
CO<sub>2</sub>–H<sub>2</sub>O isotopic exchange rate (<i>k</i><sub>iso</sub>) in six soils with pH
varying from 4.5 to 8.5. We also artificially increased the soil CA
concentration to test how pH and other soil properties (texture and
phosphate content) affected the relationship between <i>k</i><sub>iso</sub> and CA
concentration. We found that soil pH was the primary driver of <i>k</i><sub>iso</sub>
after CA addition and that the chemical composition (i.e. phosphate content)
played only a secondary role. We also found an offset between the <i>δ</i><sup>18</sup>O of the water pool with which CO<sub>2</sub> equilibrates and total soil
water (i.e. water extracted by vacuum distillation) that varied with soil
texture. The reasons for this offset are still unknown. |
| first_indexed | 2024-12-13T20:38:31Z |
| format | Article |
| id | doaj.art-b78e695d30f34458a77a4169d2794fb6 |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-13T20:38:31Z |
| publishDate | 2018-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-b78e695d30f34458a77a4169d2794fb62022-12-21T23:32:13ZengCopernicus PublicationsBiogeosciences1726-41701726-41892018-01-011559761210.5194/bg-15-597-2018The role of soil pH on soil carbonic anhydrase activityJ. Sauze0S. P. Jones1L. Wingate2S. Wohl3J. Ogée4INRA, UMR 1391 ISPA, 33140 Villenave d'Ornon, FranceINRA, UMR 1391 ISPA, 33140 Villenave d'Ornon, FranceINRA, UMR 1391 ISPA, 33140 Villenave d'Ornon, FranceINRA, UMR 1391 ISPA, 33140 Villenave d'Ornon, FranceINRA, UMR 1391 ISPA, 33140 Villenave d'Ornon, FranceCarbonic anhydrases (CAs) are metalloenzymes present in plants and microorganisms that catalyse the interconversion of CO<sub>2</sub> and water to bicarbonate and protons. Because oxygen isotopes are also exchanged during this reaction, the presence of CA also modifies the contribution of soil and plant CO<sup>18</sup>O fluxes to the global budget of atmospheric CO<sup>18</sup>O. The oxygen isotope signatures (<i>δ</i><sup>18</sup>O) of these fluxes differ as leaf water pools are usually more enriched than soil water pools, and this difference is used to partition the net CO<sub>2</sub> flux over land into soil respiration and plant photosynthesis. Nonetheless, the use of atmospheric CO<sup>18</sup>O as a tracer of land surface CO<sub>2</sub> fluxes requires a good knowledge of soil CA activity. Previous studies have shown that significant differences in soil CA activity are found in different biomes and seasons, but our understanding of the environmental and ecological drivers responsible for the spatial and temporal patterns observed in soil CA activity is still limited. One factor that has been overlooked so far is pH. Soil pH is known to strongly influence microbial community composition, richness and diversity in addition to governing the speciation of CO<sub>2</sub> between the different carbonate forms. In this study we investigated the CO<sub>2</sub>–H<sub>2</sub>O isotopic exchange rate (<i>k</i><sub>iso</sub>) in six soils with pH varying from 4.5 to 8.5. We also artificially increased the soil CA concentration to test how pH and other soil properties (texture and phosphate content) affected the relationship between <i>k</i><sub>iso</sub> and CA concentration. We found that soil pH was the primary driver of <i>k</i><sub>iso</sub> after CA addition and that the chemical composition (i.e. phosphate content) played only a secondary role. We also found an offset between the <i>δ</i><sup>18</sup>O of the water pool with which CO<sub>2</sub> equilibrates and total soil water (i.e. water extracted by vacuum distillation) that varied with soil texture. The reasons for this offset are still unknown.https://www.biogeosciences.net/15/597/2018/bg-15-597-2018.pdf |
| spellingShingle | J. Sauze S. P. Jones L. Wingate S. Wohl J. Ogée The role of soil pH on soil carbonic anhydrase activity Biogeosciences |
| title | The role of soil pH on soil carbonic anhydrase activity |
| title_full | The role of soil pH on soil carbonic anhydrase activity |
| title_fullStr | The role of soil pH on soil carbonic anhydrase activity |
| title_full_unstemmed | The role of soil pH on soil carbonic anhydrase activity |
| title_short | The role of soil pH on soil carbonic anhydrase activity |
| title_sort | role of soil ph on soil carbonic anhydrase activity |
| url | https://www.biogeosciences.net/15/597/2018/bg-15-597-2018.pdf |
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