Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Sites of naturally elevated carbon dioxide
- Migration in the ground of CO2 and other volatile contaminants. Theory and survey
- Levels of CO2 leakage in relation to geology
- CO2 emission in volcanic areas: case histories and hazards
- Controlled degassing of lakes with high CO2 content in Cameroon: an opportunity for ecosystem CO2-enrichment experiments
- Burning coal seams in southern Utah: a natural system for studies of plant responses to elevated CO2
- Long-term effects of enhanced CO2 concentrations on leaf gas exchange: research opportunities using CO2 springs
- Using Icelandic CO2 springs to understand the long-term effects of elevated atmospheric CO2
- Plant CO2 responses in the long term: plants from CO2 springs in Florida and tombs in Egypt
- Acidophilic grass communities of CO2 springs in central Italy: composition, structure and ecology
- Studying morpho-physiological responses of Scirpus lacustris from naturally CO2-enriched environments
- Carbon physiology of Quercus pubescens Wild, growing at the Bossoleto CO2 spring in central Italy
- Preliminary results on dissolved inorganic 13C and 14C content of a CO2-rich mineral spring of Catalonia (NE Spain) and of plants growing in its surroundings
- The impact of elevated CO2 on the growth of Agrostis canina and Plantago major adapted to contrasting CO2 concentrations
- Stomatal numbers in holm oak (Quercus ilex L.) leaves grown in naturally and artificially CO2-enriched environments
- Effects of CO2 on NH4+ assimilation by Cyanidium caldarium, an acidophilic hot springs and hot soils unicellular alga
- Can rising CO2 alleviate oxidative risk for the plant cell? Testing the hypothesis under natural CO2 enrichment
- Increasing concentrations of atmospheric CO2 and decomposition processes in forest ecosystems
- Index
Effects of CO2 on NH4+ assimilation by Cyanidium caldarium, an acidophilic hot springs and hot soils unicellular alga
Published online by Cambridge University Press: 10 February 2010
- Frontmatter
- Contents
- List of contributors
- Preface
- Sites of naturally elevated carbon dioxide
- Migration in the ground of CO2 and other volatile contaminants. Theory and survey
- Levels of CO2 leakage in relation to geology
- CO2 emission in volcanic areas: case histories and hazards
- Controlled degassing of lakes with high CO2 content in Cameroon: an opportunity for ecosystem CO2-enrichment experiments
- Burning coal seams in southern Utah: a natural system for studies of plant responses to elevated CO2
- Long-term effects of enhanced CO2 concentrations on leaf gas exchange: research opportunities using CO2 springs
- Using Icelandic CO2 springs to understand the long-term effects of elevated atmospheric CO2
- Plant CO2 responses in the long term: plants from CO2 springs in Florida and tombs in Egypt
- Acidophilic grass communities of CO2 springs in central Italy: composition, structure and ecology
- Studying morpho-physiological responses of Scirpus lacustris from naturally CO2-enriched environments
- Carbon physiology of Quercus pubescens Wild, growing at the Bossoleto CO2 spring in central Italy
- Preliminary results on dissolved inorganic 13C and 14C content of a CO2-rich mineral spring of Catalonia (NE Spain) and of plants growing in its surroundings
- The impact of elevated CO2 on the growth of Agrostis canina and Plantago major adapted to contrasting CO2 concentrations
- Stomatal numbers in holm oak (Quercus ilex L.) leaves grown in naturally and artificially CO2-enriched environments
- Effects of CO2 on NH4+ assimilation by Cyanidium caldarium, an acidophilic hot springs and hot soils unicellular alga
- Can rising CO2 alleviate oxidative risk for the plant cell? Testing the hypothesis under natural CO2 enrichment
- Increasing concentrations of atmospheric CO2 and decomposition processes in forest ecosystems
- Index
Summary
SUMMARY
The effect of CO2 and light on NH4+ assimilation by Cyanidium caldarium, a thermophilic acidophilic unicellular alga isolated in volcanic areas in Yellowstone National Park, USA, was investigated. N-sufficient cells assimilated NH4+ at a rate of 189 μ 4.76 umol ml-1 packed cell volume (pcv) h-1. Removal of CO2 or darkening almost immediately prevented NH4+ assimilation. N-limited cells in light assimilated NH4+ at the rate of 498 ± 8.05 pmol ml-1 pcv h-1 in the presence of CO2. In darkness they assimilated NH4+ at a rate of 303 ± 1.5 μmol ml-1 pcv h-1 in the presence of CO2, which was as high as 60% of assimilation in the light, and at a similar rate in the absence of CO2. However, after 40 min under the latter conditions, assimilation underwent a time dependent inhibition and ceased after 70 min; it was resumed upon resupply of CO2. In the absence of CO2 in light, NH4+ was assimilated at a considerably lower rate than in darkness, which supports the idea that, under CO2-free conditions, a light-dependent inhibition of NH4+ assimilation occurred. These results are consistent with the contention that cells of C. caldarium, grown under excess NH+4, obtain carbon skeletons for NH+4 assimilation exclusively by photosynthetic reactions, thereby the light and CO2 dependence. Cells grown under conditions of N-limitation possess the ability to obtain a consistent amount of additional carbon skeletons from mobilization of carbon reserves.
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- Plant Responses to Elevated CO2Evidence from Natural Springs, pp. 209 - 220Publisher: Cambridge University PressPrint publication year: 1997