Reliable design and operation of biological wastewater treatment systems demand robust models of biological degradation processes. However, methods to directly measure key bacterial growth kinetics have not been readily available. Those methods that are available rely on the classic measurement of aerobic respiration using oxygen uptake take rates. This paper shows how the thymidine assay can be used as a rapid and direct measurement of bacterial specific growth rates (mu) in situ for an anaerobic treatment process, independent of aerobic respiration. A filtration-based assay is applied and evaluated a dispersed-phase high-rate anaerobic treatment process, with results obtained in less than an hour. The chemical oxygen demand (COD) biomass in the reactor was 0.52 kg COD m(-3) and the specific growth rate of these anaerobic bacteria was 0.8 +/- 0.2 d(-1). It took the bacterial populations 21.6 hours to double. This is an important advancement from existing methods that use aerobic respiration as a pseudo measurement of bacterial specific growth rates. The method allows rapid and direct measures of microbial growth rates for anaerobic treatment processes.
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http://dx.doi.org/10.2175/106143005x89643 | DOI Listing |
Cureus
December 2024
Emergency, Hospital de Braga, Braga, PRT.
Pericardial effusion refers to the accumulation of fluid within the pericardial sac, the double-layered membrane surrounding the heart. It can be caused by various medical conditions and may lead to serious complications if not diagnosed and managed promptly. Point-of-care ultrasound (POCUS) has emerged as a valuable tool in the clinical evaluation of pericardial effusions, offering real-time visualization and aiding in the assessment of its size, characteristics, and potential hemodynamic impact.
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January 2025
Department of Chemistry, National Institute of Technology Rourkela - 769008 Odisha India +91-661-2462651 +91-661-2462980.
The self-assembled ferritin protein nanocage plays a pivotal role during oxidative stress, iron metabolism, and host-pathogen interaction by executing rapid iron uptake, oxidation and its safe-storage. Self-assembly creates a nanocompartment and various pores/channels for the uptake of charged substrates (Fe) and develops a concentration gradient across the protein shell. This phenomenon fuels rapid ferroxidase activity by an upsurge in the substrate concentration at the catalytic sites.
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January 2025
School of Physical Science and Technology, ShanghaiTech University Shanghai 201210 China
The process of proton translocation in , triggered by light, is powered by the photoisomerization of all--retinal in bacteriorhodopsin (bR). The primary events in bR involving rapid structural changes upon light absorption occur within subpicoseconds to picoseconds. While the three-state model has received extensive support in describing the primary events between the H and K states, precise characterization of each excited state in the three-state model during photoisomerization remains elusive.
View Article and Find Full Text PDFBiochem Biophys Rep
March 2025
Department of Chemistry, University of Nebraska at Kearney, USA.
Human citrate synthase (hCS) was kinetically characterized through full progress curve kinetic modelling using kinetic simulation, global fitting of the direct AcCoA to CoA transition, and a coupled thiol probe reaction to better determine the kinetics with low substrate concentration. Our analysis provides one of the most rigorous kinetic analyses of any citrate synthase ruling out the need to invoke complex cooperative mechanisms to explain progress curve data. Furthermore, we collected and modeled stopped-flow pH-dependent kinetic data with CoA and popular thiol probes such as Ellman's reagent (DTNB) and 4,4'-Dithiodipyridine (DPS), providing the opportunity for detailed kinetic simulations using these thiol probes with CoA producing enzymes.
View Article and Find Full Text PDFFront Vet Sci
January 2025
College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.
Introduction: () is a Gram-negative opportunistic pathogen, whose increasing virulence and antibiotic resistance negatively impact dairy cow health and productivity, raising concerns in livestock health management. To mitigate this risk, rapid and reliable diagnostic methods for detection are essential. Currently, detection methods for are underdeveloped, prompting us to develop both pathogenic and serological detection methods, including an optimized PCR technique and an indirect enzyme-linked immunosorbent assay (I-ELISA).
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