Application of Metabolomics for the Detection and Evaluation of Cyanopeptide Mixtures in Ontario and Quebec Lakes
Notice bibliographique
Résumé
The magnitude and frequency of cyanobacteria harmful algae blooms (cHABs) are increasing on a global scale.Anthropogenic nutrient enrichment, and climate change are drivers of bloom formation and favour cyanobacterial dominance in most aquatic ecosystems.The release of cyanotoxin mixtures by blooms into aquatic systems pose a risk to public and ecosystem health.The majority of cyanotoxin research has focused on specific groups: microcystins (MCs), cylindrospermopsins (CYNs), BMAA, saxitoxins (STXs) (anatoxins) ATXs.Other bioactive cyanopeptides (CNPs) produced by cHABs have received much less attention.The chemistry, toxicology, and environmental concentrations of the anabaenopeptin (APs), cyanopeptolin (CPs), microginin (MGs), cyanobactin (CBs), aeruginosin (ASs) CNP groups are largely unknown despite having notable biological activities and documented co-occurrence with cyanotoxins.Untargeted, targeted, and semi-targeted mass-spectrometry based metabolomic approaches were applied to study the CNP profiles of fifty-five cyanobacteria bloom samples collected from fifteen watercourses in Eastern Ontario and Western Quebec.117 unique cyanopeptides were identified and ninety-four quantitated.MCs and ferintoic acid A (FA A) were quantified with reference materials and other CNPs were determined semi-quantitatively.CPs and APs displayed the greatest diversity in group variants and possessed similar concentrations and occurrence to that of MCs.Based on environmental concentrations and ubiquity of the CP and AP groups, they are recommended for prioritization in future toxicological and environmental research.Additionally, the apparent rise in cHABs, has drawn attention from paleolimnological researchers.Historical records of cHABs are limited, and proxies of cyanobacteria occurrence are typically restricted to pigments and DNA -both of which are sensitive to environmental degradation.However, MCs produced by freshwater cyanobacteria are stable cyclic hexapeptides.MCs in lake sediment archives can provide context to both the occurrence and toxicity of historical cHABs.To evaluate the use of MCs as a paleolimnological proxy, an MC extraction and quantitation method was iii developed and validated for four MC congeners (MR RR, MC LR, [Dha 7 ]MC LR, MC LA) in lake sediments.The method was applied to sediment cores collected from the Rideau Canal system.The MC method was combined with multiple proxies of Itrax-XRF, chlorophyll-a analyses and radioscopic dating methods to develop a chronology of historical lake conditions.The multi-proxy approach provided a clear indication of increasing biological productivity towards the surface of both cores.The apparent trend of productivity appears to be a result of climate warming and anthropogenic nutrient enrichment.I would like to extend my upmost gratitude and thanks to my supervisor, David McMullin, for the continued guidance and support, and providing the opportunity to develop and expand my chemistry skillset with natural products and cyanobacteria metabolites.I am very grateful for the opportunity to attend and present at 12 th international conference on toxic cyanobacteria (ICTC) in Toledo, OH -It was a valuable experience.Thank you to Kim McDonald (MSc.) for extracting the bloom samples analyzed here and, imparting knowledge of lab operations and all things cyanobacteria.Thank you to Dr. Justin Renaud for his analytical expertise with high-resolution mass-spectrometry and metabolomics -the knowledge of analytical chemistry I gained was monumental.Thank you to Dr. Mark Sumarah for imparting both his academic guidance and expertise with the cyanopeptide bloom project.Thank you to Dr. Jesse Vermaire for collection of Rideau sediment cores, guidance with Rideau core project, and procurement of Chl-a and gamma spectroscopy data, used here.Thank you to Dr. Frances Pick for the collection and detailed information for the cyanobacteria bloom samples collected in the National Capital Region and analyzed here.Thank you to Dr. David Miller for his guidance and providing the initial reference for this master's opportunity.Thank you to Dr. Tyler Avis for both his guidance and assistance with laboratory operations and statistics.I thank Dr. Tim Patterson for the experience and knowledge of sediment core collection and the opportunity to preform such work in New Brunswick lakes.Thank you to Dr. Nawaf Nasser for imparting his knowledge of R for 14 C agedepth modelling, the workshops were fantastic.I would like to
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,002 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,001 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».