Search Results (541)

Background/Objectives: Precautionary health behaviours (PHBs), such as hand-washing or self-isolation, are non-pharmaceutical interventions used to reduce SARS-CoV-2 transmission. We investigated the potential confounding by PHBs of COVID-19 vaccine effectiveness (VE) estimates in a subset of study participants enrolled in id.DRIVE. Methods: The id.DRIVE COVID-19 VE study (formerly COVIDRIVE) is a European multicentre test-negative case–control study estimating COVID-19 VE against hospitalisation due to laboratory-confirmed SARS-CoV-2 in patients with severe acute respiratory infection. All adults (≥18 y) prospectively enrolled between 16 November 2021 and 16 August 2023 at three sites were invited to complete a PHB survey capturing indicators of PHBs in the 3 months preceding admission. Fisher’s exact test with Bonferroni-adjusted threshold was used to measure the level of association between PHB indicators and both COVID-19 vaccine status and SARS-CoV-2 test result. VE estimates were generated with and without adjustment for PHBs. Results: PHBs were modified over time, with higher precautionary attitudes in the first COVID-19 vaccine booster season (2021–2022) compared to the second one (2022–2023). For the first booster season, PHBs were positively associated with exposures (vaccination status) and outcomes (case or control status). Adjusting for PHBs led to a 6 to 9 percentage-point increase in VE estimates. Conversely, no confounding by PHBs was observed in the second booster season. Conclusions: PHBs should be considered a possible confounder of COVID-19 VE studies. Further research is needed to define when PHBs should be integrated into VE models, as the level of confounding may differ according to the study population and the epidemiological context. Full article

The work is focused on the study of the influence of different types of inorganic fillers, in combination with modifiers, on the rheological, thermal, and mechanical properties of a biodegradable mixture based on PLA/PHB. Ten types of inorganic fillers based on talc, magnesium hydroxide, aluminum hydroxide, calcium carbonate, and silicon dioxide were used in the study, along with three types of modifiers. It was concluded that fillers containing reactive OH groups on their surface act as strong pro-degradants in PLA/PHB blends, and their degrading effect can be suppressed by the addition of reactive modifiers. Each modifier acts specifically with different types of fillers. Therefore, it is necessary to select a suitable filler/modifier combination not only for fillers with different chemical compositions but also for fillers with different morphologies within the same chemical type. Moreover, the preparation of PLA/PHB/magnesium hydroxide blends with suitable processing and application properties opens the possibility of developing environmentally friendly polymeric materials with a reduced flammability. The addition of talc, which has a platelet structure, can increase the barrier properties of the mixture. Full article

In the context of the urgent global transition toward sustainable materials, this study presents a comparative environmental life cycle assessment (LCA) of poly(3-hydroxybutyrate) (PHB), a biodegradable, bio-based polymer, against conventional petrochemical plastics (polystyrene—PS; polypropylene—PP) and another popular biopolymer, namely polylactic acid (PLA). The LCA was conducted using primary production data from a laboratory-scale PHB manufacturing process, integrating real-time energy consumption measurements across all production stages. Environmental indicators such as carbon footprint and energy demand were analyzed under cradle-to-gate and end-of-life scenarios. The results indicate that PHB, while offering biodegradability and renewable sourcing, currently exhibits a significantly higher carbon footprint than PP, PS, and PLA, primarily due to its energy-intensive downstream processing. However, the environmental impact of PHB can be markedly reduced—by over 67%—through partial integration of renewable energy. PLA demonstrated the lowest production-phase emissions, while PP showed the most favorable end-of-life outcomes under municipal waste management assumptions. The study highlights the critical influence of energy sourcing, production scale, and waste treatment infrastructure on the sustainability performance of biopolymers. These findings provide practical insights for industry and policymakers aiming to reduce the environmental burden of plastics and support a shift toward circular material systems. Full article

Marine Bacteroidota are recognized bacterial producers of bioactive metabolites, yet their biosynthetic potential remains cryptic under standard laboratory conditions. Here, we developed chemically defined media for Fulvivirga kasyanovii 48LL (Cytophagia) and Tenacibaculum mesophilum fLL (Flavobacteriia) to evaluate the effect of environmentally relevant carbon sources on growth and secondary metabolism. F. kasyanovii utilized 31 of 34 tested carbon sources whereas T. mesophilum grew on only five substrates, underscoring a distinct nutritional preferences. Substrate significantly influenced the antibacterial activity of F. kasyanovii extracts. Growth on β-1,3-glucan, glycerol, poly(β-hydroxybutyrate) (PHB), fish gelatin, or pectin resulted in extracts generating the largest inhibition zones (10–13 mm) against Bacillus subtilis or Rossellomorea marisflavi. Genome analysis revealed F. kasyanovii to be enriched in biosynthetic gene clusters (BGCs), notably harboring a ~570 kb genomic island comprising five large NRPS/PKS-type clusters. Quantitative PCR confirmed carbon-source-dependent regulation of these operons: glucose induced BGC1, BGC3, and BGC4, while κ-carrageenan and PHB upregulated BGC2. Conversely, yeast–peptone medium (analogous to standard marine broth) repressed transcription across all active clusters. These findings demonstrate that naturally occurring carbon sources can selectively activate cryptic BGCs and modulate antibacterial activity in F. kasyanovii, suggesting that similar strategy can be used for natural-product discovery in marine Bacteroidota. Full article

P(3HB) is a biodegradable and biocompatible polymer, which can replace petroleum-derived plastics. Previous studies have shown that Azotobacter vinelandii strain OP-PhbP3⁺, which overexpresses the phasin protein PhbP3, produces high concentrations of P(3HB) and undergoes early autolysis, facilitating polymer release. The aim of the present study was to evaluate the performance of this strain for P(3HB) production in 3 L bioreactors and assess the feasibility of a simplified recovery process. After 36 h of cultivation, rapid cell lysis was observed, resulting in a ~50% decrease in the protein content of the cell dry weight, without reducing P(3HB) concentration, which reached 4.6 g L⁻¹. Flow cytometry analysis revealed significant morphological changes during cultivation, which was consistent with the strain’s lytic behavior. The biomass recovered at 36 h was washed with SDS, obtaining a yield of 92.5% (respect to P(3HB) initial) and a purity of 97.6%. An alternative extraction procedure using the non-halogenated solvent cyclohexanone (CYC) resulted in an even higher yield of 97.8% with a purity of 99.3% of P(3HB). Notably, the weight average molecular weight of the polymer remained stable at 8000 kDa during the entire process. Overall, the combination of PhbP3 over-expression and environmentally friendly solvents, such as CYC, enabled efficient P(3HB) production with high yield and purity while preserving polymer quality. Full article

Biocompatible nanofibrous dressings integrating bioactive compounds with antioxidative and antimicrobial properties offer a promising solution for effective wound healing. In the presented study, we developed a novel dual-delivery system by combining forcespun nanofibres with poly(3-hydroxybutyrate) (PHB)-liposomes to enhance bioavailability and enable targeted release of bioactive agents (eugenol, thymol, curcumin, ampicillin, streptomycin, gentamicin). These agents exhibited notable antioxidant activity (2.27–2.33 mmol TE/g) and synergistic or partially synergistic antimicrobial effects against E. coli, M. luteus, S. epidermidis, and P. aeruginosa ( Fractional Inhibitory Concentration index 0.09–0.73). The most potent combinations, particularly thymol, eugenol, and ampicillin, were encapsulated in the nanofibre–liposomal matrix. The successful preparation of a new combined delivery system was confirmed by structural analysis using Electron and Fluorescence Microscopy. The dual-composite materials retained the antimicrobial properties of the individual compounds upon release, with the highest increases of ~73.56% against S. epidermidis. Cell viability and in vitro immunology assays using the human keratinocyte cell line (HaCaT) showed a slight decrease in viability and immune response stimulation, while not impairing wound re-epithelisation. These findings highlight the potential of firstly reported novel carrier utilising both PHB-nanofibres and PHB-liposomes, exhibiting simultaneous antioxidant and antimicrobial activity as promising candidates for the treatment of infected wounds under oxidative stress. Full article

This work is devoted to the electrospinning of biocompatible fibrous matrixes for microbial wound therapy. The problem of treating staphylococcal-infected wounds remains urgent. In this study, we propose a new approach to the use of the chlorophyll (Chl) and poly-3-hydroxybutyrate (PHB) composite system in the treatment of infected wounds. The structure and properties of the electrospun polymer matrix based on PHB modified with various concentrations of Chl was investigated by SEM, confocal microscopy, DSC, EPR. The release rate, fluorescence, and antimicrobial activity of Chl incorporated into PHB were studied. The high efficiency of the developed materials was shown with the participation of laboratory animals. Full article

Skin repair is essential in the treatment of burns and wounds. After an injury, the concept of tissue engineering emerges to restore skin function and facilitate wound healing. This field often involves the use of biodegradable and biocompatible materials as a primary scaffold for tissue regeneration. In this study, a PHB/Collagen wound dressing mat loaded with the antimicrobial peptide LL37 was developed via electrospinning. The polymer solutions were prepared by dissolving polyhydroxybutyrate (PHB) biopolymer extracted from Cereibacter sphaeroides, commercial PHB, and marine collagen in hexafluoroisopropanol (HFIP). The resulting nanofibers were characterized using Field-Emission Scanning Electron Microscopy (FE-SEM), Thermogravimetric Analysis (TGA), X-Ray Diffractometry (XRD), and an Optical Tensiometer. Antibacterial activity assessments were conducted against Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922). Degradability studies were carried out in DMEM medium, cytotoxicity tests were performed on the L929 fibroblast cell line, and the wound healing effect was investigated on the HS2 keratinocyte cell line. To evaluate the properties of the designed material under in vitro conditions, the morphology of cells on the nanofiber was examined using an inverted light microscope. The findings demonstrated that the nanofibers were biocompatible in vitro and exhibited no toxic effects. And, compared to the control groups, the 5.56 nmol LL37-loaded PHB/Collagen nanofibers significantly enhanced wound closure by 15–30% and effectively reduced the viability of S. aureus and E. coli by 20–25% and approximately 80–85%, respectively. These results highlight the therapeutic potential of LL37-loaded PHB/Collagen nanofibers for use in wound healing applications. Full article

Background/Objectives: Colorectal cancer (CRC) remains a leading cause of cancer-related deaths, with notable sex-specific differences in its incidence, diagnosis, and outcomes. Our previous work identified casein kinase 2 alpha (CK2α) as being capable of impairing DNA mismatch repair (MMR) via phosphorylation of MLH1, thereby increasing the tumor mutational burden. This study aimed to investigate sex-specific differences in CK2α protein expression in CRC. Methods: Immunohistochemical (IHC) analysis was performed on 161 CRC tumors and adjacent normal tissues to quantify the CK2α protein levels. A multi-cohort meta-analysis of proteomic and clinical data was conducted to validate our findings and assess the correlations with age, sex, and relevant signaling pathways. Results: Female CRC patients exhibited significantly higher CK2α expression than male patients, which was confirmed in two independent cohorts. Additionally, CK2α expression was positively correlated with age in female but not male patients. Cross-cohort correlation analyses linked CK2α levels with key proteins involved in estrogen receptor signaling and aging, including DEAD-box helicase 5 (DDX5), histone deacetylase 1 (HDAC1), proliferating cell nuclear antigen (PCNA), prohibitin-2 (PHB2), H/ACA ribonucleoprotein complex subunit 2 (NHP2), and dual-specificity mitogen-activated protein kinase kinase 3 (MAP2K3). Conclusions: CK2α is significantly overexpressed in the tumor tissue of female CRC patients and shows a strong age-related correlation. These findings suggest a sex- and age-specific regulatory mechanism potentially influenced by estrogen signaling or menopause. Such dimorphisms underscore the need for sex-specific strategies in CRC biomarker development and therapy. Full article

Valorization of ricotta cheese exhausted whey (RCEW), a dairy by-product generated in large quantities worldwide, is essential to mitigate its environmental impact and unlock its economic potential. This study explores the use of RCEW as a substrate for polyhydroxyalkanoate (PHA) production by Azohydromonas lata DSM 1123. The substrate was characterized by low protein and fat contents and a relevant lactose concentration (3.81%, w/v). Due to A. lata’s inability to directly metabolize lactose, β-galactosidase supplementation was necessary. Mineral supplementation of pasteurized RCEW significantly improved both microbial biomass and PHA synthesis, achieving up to 25.94% intracellular PHA content, whereas pre-adaptation trials failed to enhance strain performance. Moderate nitrogen limitation in the substrate (C/N ratio 44) favored PHA synthesis (0.55 g/L) and 32.74% intracellular accumulation. Thermal treatments decreased initial microbial contamination, hence a balanced mixture of pasteurized–sterilized (75:25) substrate was used to modulate RCEW protein content without the inclusion of additional technological or chemical processing steps and without lactose loss or dilution. Bioreactor trials using optimized RCEW pre-treatment conditions led to a further increase in biomass (2.36 g/L) and PHA production (0.88 g/L), especially under fed-batch conditions. The extracted polymer was confirmed to be polyhydroxybutyrate (PHB), with high thermal stability and a molecular weight of 5.9 KDa. Full article

Adipose tissue exhibits dynamic metabolic and structural changes in response to environmental stimuli, including temperature fluctuations. While continuous cold exposure has been extensively studied, the molecular effects of prolonged intermittent cold exposure (ICE) remain poorly characterized. Here, we present a proteomic analysis of inguinal white adipose tissue (IWAT) from mice subjected to a 16-week regimen of short-term daily ICE (6 °C for 6 h, 5 days per week) without compensatory caloric intake. Mass spectrometry identified 1108 proteins, with 140 differentially expressed between experimental and control groups. ICE significantly upregulated mitochondrial proteins associated with lipid and carbohydrate catabolism, the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, and lipogenesis, including LETM1, AIFM1, PHB, PHB2, ACOT2, NDUA9, and ATP5J. These changes reflect enhanced metabolic activity and mitochondrial remodeling. In contrast, proteins linked to oxidative stress, insulin resistance, inflammation, and extracellular matrix remodeling were downregulated, such as HMGB1, FETUA, SERPH1, RPN1, and AOC3. Notably, gamma-synuclein (SYUG), which inhibits lipolysis, was undetectable in ICE-treated samples. Our findings support the hypothesis that ICE promotes thermogenic reprogramming and metabolic rejuvenation in subcutaneous fat through activation of futile cycles and mitochondrial restructuring. This study offers molecular insights into adaptive thermogenesis and presents intermittent cold exposure as a potential strategy to mitigate adipose tissue aging. Full article

This study highlights a new avenue to improve polyhydroxybutyrate (PHB) productivity by optimizing genes related to arginine catabolism, which influences nitrogen metabolism in cyanobacteria based on the carbon/nitrogen metabolism balance. In the Synechocystis sp. PCC 6803 wild type (WT) and its adc1 mutant (Δadc1), the native putA gene, responsible for the oxidation of proline to glutamate, was overexpressed to create the OXPutA and OXPutA/Δadc1 strains, respectively. PHB accumulation was considerably higher in OXPutA and OXPutA/Δadc1 under the nitrogen-deprived condition than in strains that overexpressed the proC gene, involved in proline synthesis. The increased transcript level of glgX, associated with glycogen degradation, confirmed that glycogen served as the primary carbon source for PHB synthesis under nitrogen stress without any carbon source addition. Furthermore, proline and glutamate level changes helped cells deal with nitrogen stress and considerably improve intracellular carbon/nitrogen metabolism. As indicated by elevated levels of proA and argD transcripts as well as chlorophyll a accumulation, this impact was most noticeable in strains that overexpressed putA, which was crucial for the synthesis of glutamate, a precursor for important metabolic pathways that respond to nitrogen stress. Therefore, our metabolic model presents PHB-producing strains as promising candidates for biomaterial biotechnology applications in medical and agricultural fields. Full article

Candida albicans and Staphylococcus aureus are opportunistic pathogens that cause life-threatening infections. This study focused on using photodynamic inactivation (PDI) to eliminate mixed biofilms of C. albicans–S. aureus formed on poly (urethane) (PU) discs functionalized with a nanocomposite layer containing phloxine B (PhB). Additionally, the effect of PDI on the ALS3 and HWP1 genes of C. albicans was examined in mixed biofilms. Spectral analysis showed a continuous release of PhB from the nanocomposite in Mueller–Hinton broth within 48 h, with a released amount of PhB < 5% of the total amount. The anti-biofilm effectiveness of the light-activated nanocomposite with PhB showed a reduction in the survival rate of biofilm cells to 0.35% and 31.79% for S. aureus and C. albicans, respectively, compared to the control biofilm on PU alone. Scanning electron microscopy images showed that the nanocomposite effectively reduced the colonization and growth of the mixed biofilm. While PDI reduced the regulation of the ALS3 gene, the HWP1 gene was upregulated. Nevertheless, the cell survival of the C. albicans–S. aureus biofilm was significantly reduced, showing great potential for the elimination of mixed biofilms. Full article

Burdock (Arctium lappa L.) is a medicinal and edible homologous plant whose roots contain many bioactive substances such as polysaccharides and phenolics. This study explored the integration of burdock powder and lactic acid bacteria fermentation to enhance the nutritional quality, sensory attributes, and flavor profiles of duck sausages. Three bacterial strains, Lacticaseibacillus casei, L. helveticus, and L. plantarum, were selected based on sensory analysis, and their effects on sausage properties were evaluated through combined fermentation trials. The results demonstrated that duck sausages fermented with L. plantarum and L. helveticus and supplemented with 3% burdock powder (PHB group) exhibited > 1.5-fold higher antioxidant activity (ABTS at 85.2 μmol trolox/g and DPPH at 92.7 μmol trolox/g, respectively; p < 0.05) and 15% increase in total phenolic content (8.24 mg gallic acid/g) compared to non-fermented counterparts. The PHB formulation also enhanced color stability (lightness, redness, yellowness), textural characteristics (hardness, springiness, cohesiveness), and sensory acceptability. Volatile compound analysis revealed a reduction in off-odor aldehydes (hexanal, (E)-2-octenal, (E)-2-decenal, and (E,E)-2,4-decadienal) and increased production of desirable aromatic compounds like tetramethyl-pyrazine. These findings highlight the potential of combining lactic acid bacteria fermentation with burdock powder to develop functional duck sausages with improved nutritional and sensory properties. Full article

The environmental burden of conventional plastics has sparked interest in sustainable alternatives such as polyhydroxyalkanoates (PHAs). However, despite ample research in bioprocess development and the use of inexpensive waste streams, production costs remain a barrier to widespread commercialization. Complementary to this, genetic engineering offers another avenue for improved productivity. Cupriavidus necator stands out as a model host for PHA production due to its substrate flexibility, high intracellular polymer accumulation, and tractability to genetic modification. This review delves into metabolic engineering strategies that have been developed to enhance the production of poly(3-hydroxybutyrate) (PHB) and related copolymers in C. necator. Strategies include the optimization of central carbon flux, redox and cofactor balancing, adaptation to oxygen-limiting conditions, and fine-tuning of granule-associated protein expression and the regulatory network. This is followed by outlining engineered pathways improving the synthesis of PHB copolymers, PHBV, PHBHHx, and other emerging variants, emphasizing genetic modifications enabling biosynthesis based on unrelated single-carbon sources. Among these, enzyme engineering strategies and the establishment of novel artificial pathways are widely discussed. In particular, this review offers a comprehensive overview of promising engineering strategies, serving as a resource for future strain development and positioning C. necator as a valuable microbial chassis for biopolymer production at an industrial scale. Full article