State of knowledge concerning modelling of anaerobic fermentation processes

Obecnie wiele zjawisk bądź procesów zachodzących w przyrodzie opisuje się za pomocą modeli matematycznych, które pomagają zrozumieć dane zjawisko, jak i również umożliwiają sprawdzenie rezultatów danego procesu, bez konieczności przeprowadzania czasem bardzo kosztownych badań. W przypadku biogazowni rolniczych, w których zachodzi wiele różnych procesów (np. hydroliza, metanogeneza, octanogeneza), powstało wiele kalkulatorów biogazowych i zostało opracowanych wiele modeli matematycznych o zróżnicowanym poziomie kompleksowości ujęcia procesu fermentacji. Celem pracy było dokonanie dogłębnej analizy opracowanych i znanych w literaturze modeli matematycznych pod względem doboru parametrów determinujących produkcję metanu, a także sposobu oszacowania tej produkcji.Presently, many phenomena or processes taking place in the environment is described with the use of mathematical models, which help to understand a particular phenomena as well as enable verification of results of a given process without the necessity of carrying out sometimes very expensive research. In case of agricultural biogas plants, where numerous various processes take place (e.g. hydrolysis, methanogenesis, acetogenesis), many biogas calculators were produced and many mathematical models of a varied level of complexity of fermentation process perspectives were developed. The aim of the paper was to carry out thorough analysis of developed and known in the literature mathematical models on account of selection of parameters which determine methane production and the manner of assessing this production

Modelling the course of anaerobic digestion process based on basic factors, which control the process

Fermentacja anaerobowa jest bardzo złożonym i rozbudowanym procesem składającym się z kilku zależnych od siebie etapów wymagającym znajomości biologii, chemii, fizyki. Niestety w dostępnej literaturze niewiele można znaleźć badań opisujących wpływ parametrów na przebieg rozwoju mikroorganizmów metanogennych w warunkach jakie panują w biogazowniach. Stąd też w artykule podjęto próbę wyznaczenia czynników, które mają największy wpływ na produkcje biogazu. Analizę przeprowadzono na podstawie danych zawartych w literaturze dotyczących produkcji biogazu czego efektem końcowym było wyznaczenie parametrów determinujących przebieg procesu fermentacji anaerobowej i opracowanie koncepcji modelu matematycznego opisującego proces. Umożliwi to dokładne scharakteryzowanie jak dane parametry wpływają na ten proces, a także pozwoli na napisanie równania matematycznego obliczającego potencjalną produkcję biogazu, możliwie najbliższą rzeczywistej wartości.Anaerobic digestion is a very complex and developed process consisting in few dependable stages, which require the knowledge of biology, chemistry and physics. Unfortunately, not much information on the research on influence of parameters on the course of methanogens microorganisms' development in the biogas works conditions can be found in the literature, which is accessible. That is why, the article tries to determine the factors, which influence biogas production in the highest degree. The analysis was carried out based on data included in the literature concerning biogas production, the result of which was determining parameters that influence the course of anaerobic digestion and compiling the idea of a mathematical model, which describes the process. It will allow for precise description on how the particular parameters influence the process, as well as for elaborating a mathematical equation, which would calculate potential biogas production, which would be the closest to the real value

Drying silica-nanofluid droplets

Exsiccation of suspension droplets generates characteristic ring-like stains. The homogeneity of such coffee rings is disturbed by subsequent cracking. Placing silica droplets on copper and stainless steel substrates, the ensuing drying and cracking chronology is investigated. The formation of the coffee ring and its cracking are visualised through microscopic imaging and videotaping. Based on the cracking chronology, three crack generations are identified. The evolution of the 1st crack generation is studied in detail. Two fracture types – logarithmic spiral and straight radially oriented – characterise these initial cracks. While the first type is due to deposition delamination, the straight cracks are induced by the interplay of capillary pressure and shear stress between coating and substrate. Most noteworthy is our finding that the cracking speed of the straight cracks is one order of magnitude larger than that of the spiral cracks. The pattern of the 1st generation cracks defines the final crack network. Our findings provide a comprehensive understanding of the crack pattern formation following the desiccation of silica droplets. This study offers details on nanofluid exsiccation on metal substrates, thereby opening routes for depositing nanoparticles on heated and non-heated surfaces for various engineering applications

Calcified Shrimp Waste Supported Pd NPs as an Efficient Catalyst toward Benzene Destruction

Shrimp waste (SW) was calcified to CaCO3 and CaO with variant morphologies by simple calcination in air and used as efficient support for Pd NPs (<7 nm) in benzene oxidation. A combination of in situ diffuse reflectance fourier transform (DRIFT), hydrogen temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were utilized to study the physicochemical properties and reveal the possible oxidation mechanism. The existence of both Pd2+ and Pd0 was essential for the oxidation activity. The 0.5-Pd/SW@600 catalyst with low activation energy (Ea = 50 kJ/mol) presented the best activity among the calcified SW supports. The observed performances correlated with the high Pd metal dispersion, the nature and morphology of the support, and the synergistic effect between the small Pd NPs and the SW support. In addition, the catalyst showed desirable stability and exceptional reusability, being highly resistant to CO2 and H2O vapor. Considering their green, high efficiency, but cost-effective nature, the biogenic Pd/SW catalysts are promising catalysts, and a million tons of SW can find application as support in benzene abatement. © 2019 American Chemical Society

Androgen receptor signaling in the lungs mitigates inflammation and improves the outcome of influenza in mice.

Circulating androgens can modulate immune cell activity, but the impact of androgens on viral pathogenesis remains unclear. Previous data demonstrate that testosterone reduces the severity of influenza A virus (IAV) infection in male mice by mitigating pulmonary inflammation rather than by affecting viral replication. To examine the immune responses mediated by testosterone to mitigate IAV-induced inflammation, adult male mice remained gonadally intact or were gonadectomized and treated with either placebo or androgen-filled (i.e., testosterone or dihydrotestosterone) capsules prior to sublethal IAV infection. Like intact males, treatment of gonadectomized males with androgens improved the outcome of IAV infection, which was not mediated by changes in the control of virus replication or pulmonary cytokine activity. Instead, androgens accelerated pulmonary leukocyte contraction to limit inflammation. To identify which immune cells were contracting in response to androgens, the composition of pulmonary cellular infiltrates was analyzed and revealed that androgens specifically accelerated the contraction of total pulmonary inflammatory monocytes during peak disease, as well as CD8+ T cells, IAV-specific CD8+ T numbers, cytokine production and degranulation by IAV-specific CD8+ T cells, and the influx of eosinophils into the lungs following clearance of IAV. Neither depletion of eosinophils nor adoptive transfer of CD8+ T cells could reverse the ability of testosterone to protect males against IAV suggesting these were secondary immunologic effects. The effects of testosterone on the contraction of immune cell numbers and activity were blocked by co-administration of the androgen receptor antagonist flutamide and mimicked by treatment with dihydrotestosterone, which was also able to reduce the severity of IAV in female mice. These data suggest that androgen receptor signaling creates a local pulmonary environment that promotes downregulation of detrimental inflammatory immune responses to protect against prolonged influenza disease

Extracellular vesicles enhance pulmonary transduction of stably associated adeno‐associated virus following intratracheal administration

Abstract Adeno‐associated virus (AAV) vector has shown multiple clinical breakthroughs, but its clinical implementation in inhaled gene therapy remains elusive due to difficulty in transducing lung airway cells. We demonstrate here AAV serotype 6 (AAV6) associated with extracellular vesicles (EVs) and secreted from vector‐producing HEK‐293 cells during vector preparation (EVAAV6) as a safe and highly efficacious gene delivery platform for inhaled gene therapy applications. Specifically, we discovered that EVAAV6 provided markedly enhanced reporter transgene expression in mucus‐covered air‐liquid interface (ALI) cultures of primary human bronchial and nasal epithelial cells as well as in mouse lung airways compared to standard preparations of AAV6 alone. Of note, AAV6 has been previously shown to outperform other clinically tested AAV serotypes, including those approved by the FDA for treating non‐lung diseases, in transducing ALI cultures of primary human airway cells. We provide compelling experimental evidence that the superior performance of EVAAV6 is attributed to the ability of EV to facilitate mucus penetration and cellular entry/transduction of AAV6. The tight and stable linkage between AAV6 and EVs appears essential to exploit the benefits of EVs given that a physical mixture of individually prepared EVs and AAV6 failed to mediate EV‐AAV6 interactions or to enhance gene transfer efficacy

Data from: Sustained fitness gains and variability in fitness trajectories in the long-term evolution experiment with Escherichia coli

Many populations live in environments subject to frequent biotic and abiotic changes. Nonetheless, it is interesting to ask whether an evolving population's mean fitness can increase indefinitely, and potentially without any limit, even in a constant environment. A recent study showed that fitness trajectories of Escherichia coli populations over 50 000 generations were better described by a power-law model than by a hyperbolic model. According to the power-law model, the rate of fitness gain declines over time but fitness has no upper limit, whereas the hyperbolic model implies a hard limit. Here, we examine whether the previously estimated power-law model predicts the fitness trajectory for an additional 10 000 generations. To that end, we conducted more than 1100 new competitive fitness assays. Consistent with the previous study, the power-law model fits the new data better than the hyperbolic model. We also analysed the variability in fitness among populations, finding subtle, but significant, heterogeneity in mean fitness. Some, but not all, of this variation reflects differences in mutation rate that evolved over time. Taken together, our results imply that both adaptation and divergence can continue indefinitely—or at least for a long time—even in a constant environment

A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2 protects against disease and elicits neutralizing antibodies to wild-type and Delta variants

Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, desirability of different routes of administration, and emergence of SARS-CoV-2 variants such as the Delta variant. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden Syrian hamster (Mesocricetus auratus) model of COVID-19. Intranasal immunization resulted in high titres of blood anti-RBD IgG as well as detectable mucosal responses. Neutralizing antibody activity against wild-type and Delta variants was evident in all vaccinated subjects. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided body mass loss, had lower virus titres in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches

A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2 protects against disease and elicits neutralizing antibodies to wild-type and Delta variants

vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, desirability of different routes of administration, and emergence of SARS-CoV-2 variants such as the Delta variant. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden Syrian hamster (Mesocricetus auratus) model of COVID-19. Intranasal immunization resulted in high titers of blood anti-RBD IgG as well as detectable mucosal responses. Neutralizing antibody activity against wild-type and Delta variants was evident in all vaccinated subjects. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided body mass loss, had lower virus titers in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches

Mutation.Rate.Data

This file contains the mutation rate data from the fluctuation tests in Table S8 in the manuscript