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International Journal of Biological... Jun 2024Active bacterial nanocellulose (BNC) nanopapers containing Salvia officinalis essential oil (SEO) in free form and encapsulated with β-cyclodextrin (βCD) were...
Active bacterial nanocellulose (BNC) nanopapers containing Salvia officinalis essential oil (SEO) in free form and encapsulated with β-cyclodextrin (βCD) were prepared, and their effect on the shelf life extension of shrimp was investigated. The GC-MS analysis of the SEO indicated the presence of various active compounds such as Thujone (21.53 %), Ledol (12.51 %) and Eucalyptol (11.28 %) in the essential oil composition. The cytotoxicity of the SEO and SEO-βCD complexes in the L929 cell line was quite low. FTIR analysis revealed new interactions in the nanopapers containing SEO-βCD complexes. Microscopic images showed that SEO-βCD complexation improved the surface morphology of the BNC nanopapers, whereas free SEO had a negative effect. X-ray diffraction patterns of the nanopapers showed higher crystallinity of the SEO-βCD containing nanopapers than that of the SEO-incorporated nanopapers. Moreover, the addition of the SEO-βCD complex improved the thermal properties of the BNC nanopaper. Water contact angle analysis showed higher hydrophobicity of the samples containing free SEO than that of the other samples. Both SEO-βCD and free SEO increased the elongation at break and decreased the tensile strength of the nanopaper. The prepared active films showed a greater antimicrobial effect on L. monocytogenes than on E. coli. The results showed a higher antioxidant capacity of the free SEO-containing nanopapers (58-78 %). The desirable effects of the active nanopapers on shrimp preservation were demonstrated by the results obtained for the microbial load, pH, and volatile nitrogen content of the product. The results demonstrate the potential of the prepared BNC active nanopapers for use in active antioxidant/antimicrobial food packaging.
PubMed: 38945710
DOI: 10.1016/j.ijbiomac.2024.133354 -
Food Research International (Ottawa,... Aug 2024Sheep's milk (SM) is known to differ from cow's milk (CM) in nutritional composition and physicochemical properties, which may lead to different digestion behaviours....
Sheep's milk (SM) is known to differ from cow's milk (CM) in nutritional composition and physicochemical properties, which may lead to different digestion behaviours. This work aimed to investigate the impact of the species (cow vs sheep) and the structure (milk vs yogurt) on the digestion of dairy products. Using an in vitro static gastrointestinal digestion model, CM, SM, cow's milk yogurt (CY) and sheep's milk yogurt (SY) were compared on particle size evolution, microscopic observations, degree of lipolysis, degree of proteolysis, specific protein degradation and calcium bioaccessibility. Species and structure affected particle size evolution during the gastric phase resulting in smaller particles for yogurts compared to milks as well as for CM products compared to SM products. Species impacted lipid composition and lipolysis, with SM products presenting higher short/medium-chain fatty acids content and higher intestinal degree of lipolysis. Proteolysis was influenced by structure, with milks showing higher intestinal degree of proteolysis compared to yogurts. Caseins were digested faster in CM, ⍺-lactalbumin was digested faster in SM despite its higher concentration, and during gastric digestion β-lactoglobulin was more degraded in CM products compared to SM products and more in yogurts compared to milks. Lastly, SM products released more bioaccessible calcium than CM products. In conclusion, species (cow vs sheep) impacted more the digestion compared to the structure (milk vs yogurt). In fact, SM was different from CM mainly due to a denser protein network that might slow down the accessibility of the enzyme to its substrate which induce a delay of gastric disaggregation and thus lead to slower the digestion of the nutrients.
Topics: Animals; Digestion; Cattle; Yogurt; Sheep; Milk; Lipolysis; Proteolysis; Particle Size; Lactoglobulins; Gastrointestinal Tract; Dairy Products; Lactalbumin; Caseins; Species Specificity; Milk Proteins
PubMed: 38945616
DOI: 10.1016/j.foodres.2024.114604 -
Food Research International (Ottawa,... Aug 2024Food comprises proteins, lipids, sugars and various other molecules that constitute a multicomponent biological system. It is challenging to investigate microscopic... (Review)
Review
Food comprises proteins, lipids, sugars and various other molecules that constitute a multicomponent biological system. It is challenging to investigate microscopic changes in food systems solely by performing conventional experiments. Molecular dynamics (MD) simulation serves as a crucial bridge in addressing this research gap. The Groningen Machine for Chemical Simulations (GROMACS) is an open-source, high-performing molecular dynamics simulation software that plays a significant role in food science research owing to its high flexibility and powerful functionality; it has been used to explore the molecular conformations and the mechanisms of interaction between food molecules at the microcosmic level and to analyze their properties and functions. This review presents the workflow of the GROMACS software and emphasizes the recent developments and achievements in its applications in food science research, thus providing important theoretical guidance and technical support for obtaining an in-depth understanding of the properties and functions of food.
Topics: Molecular Dynamics Simulation; Food Technology; Software
PubMed: 38945587
DOI: 10.1016/j.foodres.2024.114653 -
Free Radical Biology & Medicine Jun 2024To date, Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver disease associated with clinical complications. Dietary fatty acids have been...
BACKGROUND
To date, Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver disease associated with clinical complications. Dietary fatty acids have been suggested to be involved in preventing or reversing the accumulation of hepatic fat. However, contradicting roles of monounsaturated fatty acids to the liver have been implicated in various human and murine models, mainly due to the insolubility nature of fatty acids.
METHODS
High pressure homogenization methods were used to fabricate oleic acid embedded lipid nanoparticles (OALNs). The in vitro and in vivo models were used to validate the physiological effect of this OALNs via various cellular and molecular approaches including cell viability essay, fluorescent staining, electron microscope, RNAseq, qPCR, Western blots, and IHC staining.
RESULTS
We successfully fabricated OALNs with enhanced stability and solubility. More importantly, lipid accumulation was successfully induced in hepatocytes via the application of OALNs in a dose-dependent manner. Overload of OALNs resulted in ROS accumulation and apoptosis of hepatocytes dose-dependently. With the help of transcriptome sequencing and traditional experimental approaches, we demonstrated that the lipotoxic effect induced by OALNs was exerted via the DDIT3/BCL2/BAX/Caspases signaling. Moreover, we also verified that OALNs induced steatosis and subsequent apoptosis in the liver of mice via the activation of DDIT3 in vivo.
CONCLUSIONS
In all, our results established a potential pathogenic model of NAFLD for further studies and indicated the possible involvement of DDIT3 signaling in abnormal steatosis process of the liver.
PubMed: 38945456
DOI: 10.1016/j.freeradbiomed.2024.06.024 -
Journal of Microbiological Methods Jun 2024The ability to acquire three-dimensional (3D) information of cellular structures without the need for fluorescent tags or staining makes holotomographic imaging a...
The ability to acquire three-dimensional (3D) information of cellular structures without the need for fluorescent tags or staining makes holotomographic imaging a powerful tool in cellular biology. It provides valuable insights by measuring the refractive index (RI), an optical parameter describing the phase delay of light that passes through the living cell. Here, we demonstrate holotomographic imaging on industrial relevant ascomycete fungi and study their development and morphogenesis. This includes conidial germination, subcellular dynamics, and cytoplasmic flow during hyphal growth in Aspergillus niger. In addition, growth and budding of Aureobasidium pullulans cells are captured using holotomographic microscopy. Coupled to fluorescence imaging, lipid droplets, vacuoles, the mitochondrial network, and nuclei are targeted and analyzed in the 3D RI reconstructed images. While lipid droplets and vacuoles can be assigned to a specific RI pattern, mitochondria and nuclei were not pronounced. We show, that the lower sensitivity of RI measurements derives from the fungal cell wall that acts as an additional barrier for the illumination light of the microscope. After cell wall digest of hyphae and protoplast formation of A. niger expressing GFP-tagged histone H2A, location of nuclei could be determined by non-invasive RI measurements. Furthermore, we used coupled fluorescence microscopy to observe migration of nuclei in unperturbed hyphal segments and duplication during growth on a single-cell level. Detailed micromorphological studies in Saccharomyces cerevisiae and Trichoderma reesei are challenging due to cell size restrictions. Overall, holotomography opens up new avenues for exploring dynamic cellular processes in real time and enables the visualization of fungi from a new perspective.
PubMed: 38945304
DOI: 10.1016/j.mimet.2024.106983 -
Chemosphere Jun 2024Antibiotics such as sulfamethoxazole (SUF), ciprofloxacin (CIP) and erythromycin (ERY) are frequently detected in water systems without being efficiently removed during...
Antibiotics such as sulfamethoxazole (SUF), ciprofloxacin (CIP) and erythromycin (ERY) are frequently detected in water systems without being efficiently removed during water treatment. This study synthesized a graphitic carbon nitride-enhanced vanadium ferrite (VFeO@g-CN) as a photocatalyst for degrading SUF, CIP and ERY in an aqueous solution. VFeO@g-CN was characterized with X-ray diffractometry (XRD), thermogravimetry analysis (TGA), ultraviolet (UV)-visible spectrophotometry, scanning electron microscope (SEM) and transmission electron microscope (TEM). The XRD characterization of VFeO@g-CN revealed diffraction patterns with a crystallite size of 22.45 nm and a bandgap energy of 1.94 eV. The SEM image revealed the surface to be rough with irregular particle shape and size. The TEM image showed an average particle size of 92.47 nm. VFeO@g-CN exhibited a degradation efficiency, which showed complete removal of SUF (100 %) from solution while the efficiency towards CIP is 94 ± 0.60 % and 90 ± 0.8 % towards ERY. The best photocatalytic performance was achieved with 0.12 g L of VFeO@g-CN and pH = 7.0 as the optimal conditions for achieving complete removal of SUF, CIP and ERY at a concentration lower than 10.00 mg L under visible-light irradiation. The photodegradation of SUF, CIP and ERY by VFeO@g-CN was found to be promoted by ROS with ˙OH and SO˙ radicals playing a significant role. VFeO@g-CN demonstrated a regeneration capacity that is above 90 % at the 10 cycle of regeneration treatment, suggesting it to be stable and reusable with the X-ray diffraction pattern remaining unchanged and no leaching of VFeO@g-CN into solution. The result from the study reveals VFeO@g-CN as a promising photocatalyst for removing antibiotics from an aqueous solution.
PubMed: 38945222
DOI: 10.1016/j.chemosphere.2024.142733 -
Journal de Mycologie Medicale Jun 2024Pathogenic fungi are a major threat to public health, and fungal infections are becoming increasingly common and treatment resistant. Chitin, a component of the fungal...
BACKGROUND & AIM
Pathogenic fungi are a major threat to public health, and fungal infections are becoming increasingly common and treatment resistant. Chitin, a component of the fungal cell wall, modifies host immunity and contributes to antifungal resistance. Moreover, chitin content is regulated by chitin synthases and chitinases. However, the specific roles and mechanisms remain unclear. In this study, we developed a cytometric imaging assay to quantify chitin content and identify the distribution of chitin in the yeast cell wall.
METHODS
The Candida albicans SC5314 and Nakaseomyces glabratus (ex. C. glabrata) ATCC2001 reference strains, as well as 106 clinical isolates, were used. Chitin content, distribution, and morphological parameters were analysed in 12 yeast species. Moreover, machine learning statistical software was used to evaluate the ability of the cytometric imaging assay to predict yeast species using the values obtained for these parameters.
RESULTS
Our imaging-cytometry assay was repeatable, reproducible, and sensitive to variations in chitin content in C. albicans mutants or after antifungal stimulation. The evaluated parameters classified the yeast species into the correct clade with an accuracy of 85 %.
CONCLUSION
Our findings demonstrate that this easy-to-use assay is an effective tool for the exploration of chitin content in yeast species.
PubMed: 38945044
DOI: 10.1016/j.mycmed.2024.101493 -
Journal of Hazardous Materials Jun 2024Biodegradation of polyethylene (PE) plastics is environmentally friendly. To obtain the laccases that can efficiently degrade PE plastics, we generated 9 ancestral...
Biodegradation of polyethylene (PE) plastics is environmentally friendly. To obtain the laccases that can efficiently degrade PE plastics, we generated 9 ancestral laccases from 23 bacterial three-domain laccases through ancestral sequence reconstruction. The optimal temperatures of the ancestral laccases were between 60 °C-80 °C, while their optimal pHs were at 3.0 or 4.0. Without substrate pretreatment and mediator addition, all the ancestral laccases can degrade low-density polyethylene (LDPE) films at pH 7.0 and 60 °C. Among them, Anc52, which shared low sequence identity (18 %-41.7 %) with the reported PE-degrading laccases, was the most effective for LDPE degradation. After the catalytic reactions at 90 °C for 14 h, Anc52 (0.2 mg/mL) induced clear wrinkles and deep pits on the PE film surface detected by scanning electron microscope, and its carbonyl and hydroxyl indices reached 2.08 and 2.42, respectively. Then, we identified the residues 203 and 288 critical for PE degradation through site-directed mutation on Anc52. Moreover, Anc52 be activated by heat treatment (60 °C and 90 °C) at pH 7.0, which gave it a high catalytic efficiency (k/K= 191.73 mM·s) and thermal stability (half-life at 70 °C = 13.70 h). The ancestral laccases obtained here could be good candidates for PE biodegradation.
PubMed: 38944993
DOI: 10.1016/j.jhazmat.2024.135012 -
Food Chemistry Jun 2024Based on the three typical gels under KCl substitution groups, the effect of partial substitution of NaCl by KCl (groups: T 1:0.6 M NaCl; T 2: 0.3 M NaCl +0.3 M KCl;...
Based on the three typical gels under KCl substitution groups, the effect of partial substitution of NaCl by KCl (groups: T 1:0.6 M NaCl; T 2: 0.3 M NaCl +0.3 M KCl; T 3: 0.2 M NaCl +0.4 M KCl; T 4:0.6 M KCl) on the aggregation behavior and gel characteristics of myosin was evaluated. The significant changes in hydrophobicity and sulfhydryl content (P < 0.05) indicate KCl substitution enhances myosin aggregation through hydrophobic interactions and disulfide bonds. According to Ca-ATP, scanning electron microscopes (SEM) and the rheological results, T2 had a smoother network structure at about 75 °C. Noticeably, T3 had high water holding capacity (WHC), but its gel had some visible cavities. T4 had a gel structure with several irregular aggregates due to a greater aggregation rate. Thus, appropriate partial substitution of NaCl by KCl could enhance beef myosin gel properties and heat-induced aggregation behavior.
PubMed: 38944923
DOI: 10.1016/j.foodchem.2024.140178 -
Journal of Structural Biology Jun 2024Developments in direct electron detector technology have played a pivotal role in enabling high-resolution structural studies by cryo-EM at 200 and 300 keV. Yet,...
Developments in direct electron detector technology have played a pivotal role in enabling high-resolution structural studies by cryo-EM at 200 and 300 keV. Yet, theory and recent experiments indicate advantages to imaging at 100 keV, energies for which the current detectors have not been optimized. In this study, we evaluated the Gatan Alpine detector, designed for operation at 100 and 200 keV. Compared to the Gatan K3, Alpine demonstrated a significant DQE improvement at these voltages, specifically a ∼ 4-fold improvement at Nyquist at 100 keV. In single-particle cryo-EM experiments, Alpine datasets yielded better than 2 Å resolution reconstructions of apoferritin at 120 and 200 keV on a ThermoFisher Scientific (TFS) Glacios microscope fitted with a non-standard SP-Twin lens. We also achieved a ∼ 3.2 Å resolution reconstruction for a 115 kDa asymmetric protein complex, proving its effectiveness with complex biological samples. In-depth analysis revealed that Alpine reconstructions are comparable to K3 reconstructions at 200 keV, and remarkably, reconstruction from Alpine at 120 keV on a TFS Glacios surpassed all but the 300 keV data from a TFS Titan Krios with GIF/K3. Additionally, we show Alpine's capability for high-resolution data acquisition and screening on lower-end systems by obtaining ∼ 3 Å resolution reconstructions of apoferritin and aldolase at 100 keV and detailed 2D averages of a 55 kDa sample using a side-entry cryo holder. Overall, we show that Gatan Alpine performs well with the standard 200 keV imaging systems and may potentially capture the benefits of lower accelerating voltages, possibly bringing smaller sized particles within the scope of cryo-EM.
PubMed: 38944401
DOI: 10.1016/j.jsb.2024.108108