ACQUISITION OF INORGANIC CARBON BY THE MARINE HAPTOPHYTE <i>ISOCHRYSIS GALBANA</i> (PRYMNESIOPHYCEAE)<sup>1</sup>
Bibliographic record
Abstract
Inorganic carbon acquisition has been investigated in the marine haptophyte Isochrysis galbana. External carbonic anhydrase (CA) was present in air‐grown (0.034% CO 2 ) cells but completely repressed in high (3%) CO 2 ‐grown cells. External CA was not inhibited by 1.0 mM acetazolamide. The capacity of cells to take up bicarbonate was examined by comparing the rate of photosynthetic O 2 evolution with the calculated rate of spontaneous CO 2 supply; at pH 8.2 the rates of O 2 evolution exceeded the CO 2 supply rate 14‐fold, indicating that this alga was able to take up HCO 3 − . Monitoring CO 2 concentrations by mass spectrometry showed that suspensions of high CO 2 ‐grown cells caused a rapid drop in the extracellular CO 2 in the light and addition of bovine CA raised the CO 2 concentration by restoring the HCO 3 − ‐CO 2 equilibrium, indicating that cells were maintaining the CO 2 in the medium below its equilibrium value during photosynthesis. A rapid increase in extracellular CO 2 concentration occurred on darkening the cells, indicating that the cells had accumulated an internal pool of unfixed inorganic carbon. Active CO 2 uptake was blocked by the photosynthetic electron transport inhibitor 3‐(3′,4′‐dichlorphenyl)‐1,1‐dimethylurea, indicating that CO 2 transport was supported by photosynthetic reactions. These results demonstrate that this species has the capacity to take up HCO 3 − and CO 2 actively as sources of substrate for photosynthesis and that inorganic carbon transport is not repressed by growth on high CO 2 , although external CA expression is regulated by CO 2 concentration.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".