We investigated the impact of oxygen on a strictly anaerobic, methanogenic benzene-degrading enrichment culture derived decades ago from oil-contaminated sediment. The culture includes a benzene fermenter from candidate clade Sva0485 (referred to as ORM2) and methanogenic archaea. A one-time injection of 0.1 mL air , simulating a small leak into 30 mL batch culture bottle, had no measurable impact on benzene degradation rates, although retrospectively, a tiny enrichment of aerobic taxa was detected. A subsequent 100 times larger injection of air stalled methanogenesis and caused drastic perturbation of the microbial community. A benzene-degrading became highly enriched and consumed all available oxygen. Anaerobic benzene-degrading ORM2 cell numbers plummeted during this time; re-growth and associated recovery of methanogenic benzene degradation took almost 1 year. These results highlight the oxygen sensitivity of this methanogenic culture and confirm that the mechanism for anaerobic biotransformation of benzene is independent of oxygen, fundamentally different from established aerobic pathways, and is carried out by distinct microbial communities. The study also highlights the importance of including microbial decay in characterizing and modeling mixed microbial communities.
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http://dx.doi.org/10.1021/acs.est.2c02624 | DOI Listing |
Sci Rep
January 2025
Young Researchers and Elite Club, Omidiyeh Branch, Islamic Azad University, Omidiyeh, Iran.
Accurate estimation of interfacial tension (IFT) between nitrogen and crude oil during nitrogen-based gas injection into oil reservoirs is imperative. The previous research works dealing with prediction of IFT of oil and nitrogen systems consider synthetic oil samples such n-alkanes. In this work, we aim to utilize eight machine learning methods of Decision Tree (DT), AdaBoost (AB), Random Forest (RF), K-nearest Neighbors (KNN), Ensemble Learning (EL), Support Vector Machine (SVM), Convolutional Neural Network (CNN) and Multilayer Perceptron Artificial Neural Network (MLP-ANN) to construct data-driven intelligent models to predict crude oil - nitrogen IFT based upon experimental data of real crude oils samples encountered in underground oil reservoirs.
View Article and Find Full Text PDFEnviron Pollut
January 2025
State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan province, China. Electronic address:
Dental operations inherently involve a high risk of airborne cross-infection among medical staff and patients due to the exposure of respiratory secretions, which contain pathogenic microorganisms and typically spread in the form of aerosols. In order to contribute to the understanding of aerosol dynamics during dental operation and efficiently mitigate their dispersion and deposition through appropriate ventilation, 3D numerical simulations and full-scale experimental measurements were performed in this study. The indoor airflow distribution and dynamic aerosol behaviors observed under three optimized ventilation schemes (Scenario I-III) were compared with those observed under the current ventilation system.
View Article and Find Full Text PDFRetina
January 2025
National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
Purpose: Anterior chamber air injection (ACAI) is a surgical technique used to decrease the occurrence of postoperative intraocular lens (IOL) haptic dislocation following phacovitrectomy with gas/air tamponade. The impact of this technique on IOL stability remains uncertain, prompting the design of this study to investigate further.
Methods: This study included 51 eyes of 51 patients who underwent phacovitrectomy with gas/air tamponade.
Cureus
December 2024
Trauma and Orthopaedics, Royal Devon and Exeter University Hospital, Devon, GBR.
Chronic tendinopathy is a degenerative condition characterized by persistent pain, functional limitations, and tendon thickening, often resulting from repetitive overuse or failed tendon healing. Left untreated, it can progress to tendon rupture, prolonged disability, and impaired quality of life. Management typically includes conservative therapies, such as physical therapy, corticosteroid (CS) injections for short-term relief, and platelet-rich plasma (PRP) as a regenerative therapy with potential long-term benefits.
View Article and Find Full Text PDFLangmuir
January 2025
Departamento de Química, Catedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba 5000, Argentina.
The present work focuses on one of the possible target mechanisms of action of the anionic antimicrobial peptide β-lg derived from trypsin hydrolysis of β-lactoglobulin. After confirmation of bactericidal activity against a pathogenic Gram(+) strain and demonstration of the innocuousness on a eukaryotic cell line, we investigated the interaction of β-lg with monolayers and bilayers of dpPC and dpPC:dpPG as model membranes of eukaryotic and bacterial membranes, respectively. In monolayers, compared to zwitterionic dpPC, in the negatively charged dpPC-dpPG, β-lg injected into the subphase penetrated up to higher surface pressures and showed greater extents of penetration with increasing concentration in the subphase.
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