Bioremediation of atrazine and its metabolites using a novel Bacillus thuringiensis spore-based enzyme display system
Notice bibliographique
Résumé
Bacillus thuringiensis spore-based display system has been shown to be an excellent biocatalyst platform to express the high density of the targeted enzymes to catalyze the chemical reactions. To demonstrate Bacillus thuringiensis spore-based display system can be a superior and more cost-effective approach for enzymatic bioremediation of contaminated soils as compared to conventional enzymatic techniques, this study focused on exploring and testing the utility of the biocatalyst system for decontamination of a persistent contaminant, atrazine (ATR). The first three enzymes, AtA, AtzB, and AtzC, in Pseudomonas sp. strain ADP ATR degradation pathway were incorporated into the B. thuringiensis spore display system to decontaminate ATR and its metabolites to less toxic metabolite. The environmental risk of applying the B. thuringiensis spore display system in the field was also investigated. Our findings showed that the AtzA-bearing spore exhibited enhanced enzymatic activity and stability and less washout as compared to free recombinant AtzA enzymes in soil. More than 90 percent of applied ATR (46 M [mu]10 mg L-1]) in the soil was detoxified by AtzA-bearing spores in 24 hours. Furthermore, the optimal ratio of AtzA- and AtzB-bearing spores decontaminate more than 80 percent fortified 34.5 nM (7.5 [mu]g L-1) of ATR in surface water within 24 hours, and the fortified ATR and its metabolite, hydroxy atrazine (HA), in surface water was completely converted to the end metabolite N-isopropylammelide (NiPA) at the end of 96 hours. Additionally, more than 67 percent of applied NiPA was degraded by 1 mg AtzC-bearing spores with the corresponding production of cyanuric acid in water. The enzymatic kinetics study of AtzC-bearing spores provides insightful information for determining the optimal ratio among AtzA-, AtzB-, and AtzC-bearing spores in the one-pot reactions for ATR degradation. Lastly, this is the first study to monitor the germination of B. thuringiensis spore in both surface water and soil. We found little to no germination from AtzA-bearing spores as observed in the sterile surface water incubated in the laboratory, while a small percentage (2.1-2.4 percent) of AtzA- bearing spores germinated in the sterile soil incubated in the laboratory after 4 days. In conclusion, this study demonstrated ATR decontamination by multiple enzymes delivered by B. thuringiensis spore in one-pot reactions in surface water and laid an important foundation for the environmental application of the novel B. thuringiensis spore display system. A review of possible delivery system for the novel enzyme expression platform was also included. Immediately after the outburst of the global COVID-19 pandemic in 2020, the author endeavored to serve the community as a scientist to take on the major challenge of public health. Therefore, the author has decided to suspend the Ph.D. study and direct all the efforts and energy to contribute her scientific knowledge to protect public health in responding to one of the most critical global health crises in human history. Through joining the Missouri Wastewater Surveillance Taskforce since the pandemic, a novel approach was developed to capture the real-time population dynamic for normalizing the SARS-CoV-2 viral load in the wastewater. This strategy was superior to the current approach recommended by the CDC, and it has been successfully used for predicting the infected population within the communities. This novel normalization approach has been adopted by the federal City of Bon, Germany, and the Canadian government agencies for tracking the COVID-19 infection using WBE. This strategy can be implemented to track not only infectious diseases but also to map opioids or other drug usage in the community in the future.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 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 ».