Identification of Gambierdiscus species from La Réunion and evaluation of toxicity and toxin profile
Bibliographic record
Abstract
• This study combining morphological and molecular data is the first to mention Gambierdiscus diversity in La Réunion area. • -The assemblage observed around Réunion Island comprises taxa also present in both the Atlantic and Pacific Oceans, allowing to extend the geographic distribution of these species. • It is the first time that toxicity and toxin profile of Gambierdiscus from La Réunion have been evaluated. • This study contributes to increase the coverage of secondary metabolites from Gambierdiscus strains. Five different species of Gambierdiscus have been identified in La Réunion ( G. belizeanus, G. balechii, G. pacificus, G. silvae and G . ribotype 2) by morphological observations in Scanning Electron Microscopy (SEM) and molecular identification and phylogenetic analysis. Growth rates of cultures have also been evaluated showing values from 0.09 to 0.36 d -1 . The toxicity and toxin profile of thirteen strains have been analysed by a multidisciplinary approach with Neuro-2a cell-based assay (CBA), magnetic bead-based immunoassay, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and LC coupled to high-resolution mass spectrometry (LC-HRMS). G. balechii showed the highest toxicity by CBA (∼627 fg equiv. CTX1B·cell -1 ) followed by G. ribotype 2 (76 to 13 fg equiv. CTX1B·cell -1 ), G. balechii (63 to 7 fg equiv. CTX1B·cell -1 ), G. belizeanus (30 to 20 fg equiv. CTX1B·cell -1 ) and G. pacificus with values close to LOQ but not conclusive. The toxin profile for the 13 strains was evaluated by LC-MS/MS using seven different methods and being gambierone and 44-methylgambierone the two only known compounds, found in high concentrations in all samples. Gambierone was detected from 2.05 pg ·cell -1 in G. balechii (P-0414B) to 12.91 pg·cell -1 in G. balechii (P-0414A) and 44-methylgambierone was detected from 1.93 pg·cell -1 in G. belizeanus (P-0414B) to 14.95 pg·cell -1 in G. pacificus (P-0304). These samples were analysed also by LC-HRMS, confirming gambierone and 44-methylgambierone the main compounds detected. Additionally, a potential polyether sulphur-containing compound corresponding to the novel molecular formula C 62 H 94 O 23 S ([M+NH 4 ] + , m/z 1256.6234) were tentatively identified. This study combining morphological and molecular data is the first to mention such diversity in the area. It is also the first time that toxicity and toxin profile of Gambierdiscus from La Réunion have been evaluated.
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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 | 0.001 | 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) | 0.001 | 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".