Search Results (96)

Agar can be degraded into agar-oligosaccharides by physical, chemical, and biological methods, but the further industrial application of agar-oligosaccharides has been limited by the environmental pollution of traditional agar-oligosaccharides preparation methods and the lack of novel agarase. In this study, we reported the screening of 12 strains with agar-degrading activity from sea cucumber intestine and mucus using a combination of Gram’s iodine staining and 3,5-dinitrosalicylic acid (DNS) method, during which five fungal strains exhibited high agarase activity. Their production of different agarases and agar-oligosaccharides could be visualized by zymogram assay and thin-layer chromatography. A strain ACD-11-B with the highest agarase activity showed 99.79% similarity to Aspergillus sydowii CBS593.65 for ITS rDNA sequence. Strain ACD-11-B produced five possible agarases with predicted molecular weights of 180, 95, 43, 33, and 20 kDa, approximately. The optimal temperature and pH of the crude enzyme production by strain ACD-11-B were 40 °C and 6.0. The crude enzyme was stable at 30 °C, and Ca²⁺, K⁺, and Na⁺ could increase the activity of the crude enzyme. Its agarases demonstrated remarkable salt tolerance and substrate specificity, with neoagarobiose (NA2) identified as the main degradation product. These results indicate that the fungal strain ACD-11-B can secrete agarases with potential in industrial applications, making it a new producer strain for agarase production. Full article

Quantitative phosphoproteomics enables the comprehensive analysis of signaling pathways driven by overexpressed cancer receptors, revealing the molecular mechanisms that underpin tumor progression and therapy resistance. The glycoprotein L1 cell adhesion molecule (L1CAM) is overexpressed in high-grade serous ovarian carcinoma (HGSOC) and plays a crucial role in carcinogenesis by regulating cancer stem cell properties. Here, CRISPR–Cas9-mediated knockout of L1CAM in ovarian cancer OVCAR8 and OVCAR4 cells significantly impaired anchor-independent growth in soft agar assays and reduced clonogenic survival following external beam irradiation. In vivo, L1CAM knockout decreased cancer stem cell frequency and significantly decreased tumorigenicity. To uncover L1CAM-regulated signaling networks, we employed quantitative phosphoproteomics and proteomics. Bioinformatics analyses and validation studies revealed L1CAM-associated pathways that contribute to radioresistance through DNA repair processes and mammalian target or rapamycin complex 1 (mTORC1)-mediated signaling. In conclusion, our study established a link between L1CAM-dependent tumorigenesis and radioresistance, both hallmarks of cancer stemness, with phosphorylation of key proteins involved in DNA damage response. This study further emphasizes the value of quantitative phosphoproteomics in cancer research, showcasing its ability to enhance understanding of cancer progression and therapy resistance. Full article

In this study, we aimed to develop soy protein-derived edible porous hydrogel scaffolds for cultured meat based on mechanical anisotropy to mimic the physical and biochemical properties of muscle tissues. Based on the traditional Japanese Ito-Kanten (thread agar) freeze–thaw process, we used liquid nitrogen directional freezing combined with ion crosslinking to fabricate an aligned scaffold composed of soy protein isolate (SPI), carrageenan (CA), and sodium alginate (SA). SPI, CA, and SA were dissolved in water, heated, mixed, and subjected to directional freezing in liquid nitrogen. The frozen gel was immersed in Ca²⁺ and K⁺ solutions for low-temperature crosslinking, followed by a second freezing step and lyophilization to create the SPI/CA/SA cryogel scaffold with anisotropic pore structure. Furthermore, C2C12 myoblasts were seeded onto the scaffold. After 14 d of dynamic culture, the cells exhibited significant differentiation along the aligned structure of the scaffold. Overall, our developed anisotropic scaffold provided a biocompatible environment to promote directed cell differentiation, showing potential for cultured meat production and serving as a sustainable protein source. Full article

This study investigated the effect of different culture agar media, derived from Bennett’s medium, on the antimicrobial activity of 15 Streptomyces sp. and 1 Lentzea sp. strains isolated from mining environments. The media were prepared from the standard Bennett’s medium by suppressing one, two, or three ingredients—yeast extract (YE), beef extract (BE), or casein (Cas)—while maintaining glucose (Gluc) or by substituting it with fructose (Fruc) or galactose (Gal) and keeping the same suppressions. The antimicrobial activity was investigated against Candida albicans ATCC 10231, Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 6633, and Escherichia coli K12. The antimicrobial activity of actinomycete strains was positively influenced by media modifications, though the response was actinomycete strain and target pathogen-dependent. Unexpectedly, thirteen strains exhibited poor growth on a pure agar-agar medium, including six Streptomyces strains (AS34, AS3, BS59, BS68, BS69, and DAS104) that showed notable antimicrobial activity, with inhibition zone diameters ranging from 10.75 ± 1.06 to 18.00 ± 0.00 mm. Modifications of Bennett’s medium, including replacing glucose with fructose or galactose and maintaining yeast extract or both yeast extract and beef extract, induced and enhanced the antimicrobial activity of several actinomycete strains. Notably, the new media induced antimicrobial activity in strains that showed no activity in Bennett’s medium. They led, compared to Bennett’s medium, to the detection of eight additional active strains against S. aureus, eight against B. subtilis, six against E. coli, and four against C. albicans. This study is the first to explore the modification of Bennett’s medium, either by subtraction or substitution, in order to investigate the effect on antimicrobial activity of actinomycete strains. These results highlight the importance of the composition of culture media on inducing or boosting antimicrobial activity in Streptomyces and Lentzea. Full article

Orthodontic microimplants have revolutionized anchorage in orthodontics but remain vulnerable to microbial colonization, potentially leading to infection and failure. Surface modifications incorporating silver nanoparticles (AgNPs) offer antimicrobial benefits, providing long-term protection against bacterial infections, while improving partial osseointegration. This study investigates hybrid coatings enriched with AgNPs, calcium (Ca), and phosphorus (P) to improve antimicrobial efficacy and reduce biofilm formation. Microimplants fabricated from the Ti6Al4V alloy were divided into six groups with varying surface treatments, including etching in hydrofluoric acid and hybrid layers containing 0.5 mol% AgNPs and CaP. Antibacterial activity was evaluated using agar diffusion and biofilm formation assays against S. aureus, E. coli, and S. mutans. Surface roughness was analyzed and correlated with biofilm formation. The model assessing the impact of biomaterials on S. aureus biofilm revealed a strong association (R² = 0.94), with biomaterial choice significantly influencing biofilm formation. The model for E. coli biofilm exhibited exceptional predictability (R² = 0.99). The model for S. mutans biofilm demonstrated an association (R² = 0.68). Hybrid coatings exhibited a promising antimicrobial activity. Biofilm formation was higher on microimplants with rougher surfaces. Hybrid coatings enriched with AgNPs and CaP enhance antimicrobial properties and partially reduce biofilm formation. It is suggested that the optimization of microimplant surface areas varies according to function. An enhanced performance can be achieved by maintaining a smooth surface for soft tissue contact, while incorporating a rough surface enriched with bactericidal and bioactive modifiers for bone contact areas. Full article

Rosacea is a common skin condition with quite a relevance. It currently affects at least 10% of the European population at some point after the age of 30. It is a chronic disorder that mainly affects the skin on the face and is characterized by outbreaks and remissions. Under normal circumstances, the skin face presents a wide range of commensal organisms, such as Staphylococcus epidermidis or Demodex folliculorum, but dysbiosis of the skin flora plays a relevant role in inflammatory processes and the development of the disease. Metronidazole (MD) is one of the main treatments indicated to reduce redness on the cheeks, nose, chin, or forehead and also to treat flushing, erythema, pimples, and other symptoms due in part to its anti-inflammatory action. On the other hand, clindamycin (CM) is another antibiotic used for rosacea, especially for its action against anaerobic and Gram-positive bacteria. Background/Objectives: This study aimed to develop an emulgel formulation that includes MD and CM, using excipients with non-comedogenic and non-irritating properties. Methods: The formulation was characterised physiochemically, rheological measurements were made, and short-term stability studies were carried out. In vitro release, permeation studies, toxicity an in vitro inflammation model were evaluated in a HaCaT cell model. To determine the interaction between the antibiotics, the minimum inhibitory concentration was determined separately and together using the broth microdilution method. To determine the formulation’s antimicrobial activity, an agar diffusion method was used. Results: The MD-CM-gel droplet size was measured by laser diffraction and the diameter obtained was less than 2.68 ± 0.18 µm in 50% of the particles. Suitable results was observed for the short-term stability. Release and permeation data revealed sustained drug release and adequate permeation through human skin. Non-toxicity was detected and the MD showed an anti-inflammatory effect with non-interference of CM. Also, there is no antagonism between the two antibiotics and the MD-CM-gel shows better results when compared to the formulations with the antibiotics separately and to commercial formulations. Conclusions: It is suggested that, following detailed preclinical and clinical studies, MD-CM-gel could be considered as an alternative for treating rosacea. Full article

Background: Sodium, potassium, chloride, calcium, and magnesium in urine are useful biomarkers and are commonly evaluated in patients with different conditions. Urinary tract infections are among the most common diseases worldwide. However, their treatment poses significant challenges, particularly in hospitals, primarily due to antibiotic resistance and recurrence. Objectives: To evaluate the relationship between ion concentrations in urine and the presence of infection. Methods: A total of 175 random urine samples were collected from patients who had a request for urine culture at the Cova da Beira University Hospital Centre in Portugal. In vitro contamination was also conducted, in which ten negative urine cultures were contaminated with an Escherichia coli strain to evaluate the direct effect of its presence on the concentration of the ions. Results: In total, 61 samples were found to be positive, following a consensual quantitative definition. For Ca, there was a significant association between its concentrations in positive and negative cultures. In ten negative urine cultures experimentally contaminated with an Escherichia coli strain, bacterial growth did not seem to affect the concentration of ions. In vitro contaminated samples were also inoculated on MacConkey agar and incubated. The results showed that Gram-negative bacteria do not seem to proliferate in environments with low Ca concentrations. Conclusions: The presence of higher concentrations of Ca may facilitate the multiplication of Gram-negative bacteria, which can potentially result in depletion of Ca in vivo to putatively potentiate an inflammatory response. The concentration of Na, K, Cl, and Mg does not seem to have any relationship with UTIs. Full article

Background: Papaya leaves (PLs) are known for their therapeutic benefits and traditional use in treating inflammation, infections, and various health conditions. Rich in bioactive compounds, PLs are studied for their potential applications in functional foods. This study analyzed their nutritional, phytochemical, structural, thermal, and antimicrobial properties to evaluate their role as a health-promoting ingredient. Methods: Phytochemicals were quantified spectrophotometrically and identified via GC-MS. Antioxidant activity was assessed using DPPH and FRAP assays. Mineral content was determined using ICP-OES. Structural and thermal properties were evaluated using FTIR, XRD, and calorimetry, and antimicrobial activity was tested via the agar well diffusion method. Results: PLs contained 25.75% crude protein, 41.49% carbohydrates, and high levels of flavonoids (21.00 mg QE/g), phenolics (8.85 mg GAE/g), and tannins (430 mg TAE/g). Antioxidant assays confirmed strong free radical scavenging potential. Mineral analysis showed abundant K, Ca, Mg, Na, and Fe (4071, 1079, 789.2, 361.2, and 228.2 mg/kg, respectively). Structural and thermal analysis revealed bioactive functional groups, 23.9% crystallinity, and thermal degradation characteristics. PLs exhibited antimicrobial activity, inhibiting E. coli, S. aureus, B. subtilis, and K. pneumoniae with zones of 22.05–25.15 mm. Conclusions: PLs demonstrate strong nutritional, antioxidant, and antimicrobial properties, supporting their inclusion in functional food. Full article

Background/Objectives: Microorganisms are the leading cause of infections in the root canal system, contributing to the failure of endodontic treatments. This in vitro study aimed to compare the antimicrobial effects of four different endodontic sealers: Endomethasone N (Septodont, Saint Maur-des-Fossés, France), Sealapex (Kerr Corporation, Orange, CA, USA), AH Plus Jet (Dentsply DeTrey GmbH, Konstanz, Germany), and MTA Fillapex (Angelus, Londrina, Brazil). Methods: The sealers were tested against common oral pathogens, including Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Candida albicans, and Streptococcus mutans, using the agar diffusion method. Inhibition zones were measured at 24, 48, and 72 h to assess antimicrobial efficacy. Results: The results showed that Endomethasone was the most effective sealer against all tested microorganisms, demonstrating consistent inhibition across all time intervals. MTA Fillapex also exhibited a significant antimicrobial effect, particularly against Streptococcus mutans, with its efficacy increasing over time. AH Plus Jet displayed limited effectiveness, showing significant results only against Staphylococcus aureus. Conclusions: Overall, this study confirms the superior antimicrobial performance of Endomethasone, while the other materials, particularly MTA Fillapex and Sealapex, also showed notable effects in experimental conditions. The antimicrobial activity of all materials, except AH Plus Jet, increased over the 72-h period. Full article

Environmental pollution from metal toxicity is a widespread concern. Certain bacteria hold promise for bioremediation via the conversion of toxic chromium compounds into less harmful forms, promoting environmental cleanup. In this study, we report the isolation and detailed characterization of a highly chromium-tolerant bacterium, Bacillus tropicus CRB14. The isolate is capable of growing on 5000 mg/L Cr (VI) in an LB (Luria Bertani) agar plate while on 900 mg/L Cr (VI) in LB broth. It shows an 86.57% reduction ability in 96 h of culture. It can also tolerate high levels of As, Cd, Co, Fe, Zn, and Pb. The isolate also shows plant growth-promoting potential as demonstrated by a significant activity of nitrogen fixation, phosphate solubilization, IAA (indole acetic acid), and siderophore production. Whole-genome sequencing revealed that the isolate lacks Cr resistance genes in their plasmids and are located on its chromosome. The presence of the chrA gene points towards Cr(VI) transport, while the absence of ycnD suggests alternative reduction pathways. The genome harbors features like genomic islands and CRISPR-Cas systems, potentially aiding adaptation and defense. Analysis suggests robust metabolic pathways, potentially involved in Cr detoxification. Notably, genes for siderophore and NRP-metallophore production were identified. Whole-genome sequencing data also provides the basis for molecular validation of various genes. Findings from this study highlight the potential application of Bacillus tropicus CRB14 for bioremediation while plant growth promotion can be utilized as an added benefit. Full article

This study is aimed at the development of a fermented cashew nut cheese alternative supplemented with Chondrus crispus and Porphyra sp. and the evaluation of the impact of seaweed supplementation through analysis of physicochemical, microbiological, and organoleptic properties of the developed food products. The total lipid content decreased with the supplementation with seaweeds. Crude protein content also slightly decreased, while elemental analysis showed that mineral and trace element (Ca, K, Mg, Na, Fe, I, Se, and Zn) content increased when C. crispus was added to the paste. The analyses of color and textural (TPA) attributes showed that these were significantly influenced by adding seaweeds to the cashew paste. Generally, the microbiological results comply with the different European guidelines for assessing the microbiological safety of ready-to-eat foods placed on the market, except for aerobic mesophilic bacteria and marine agar counts. Flash Profile analysis allowed for distinguishing sample attributes, showing an increased flavor complexity of the plant-based cheese alternatives supplemented with seaweeds. Overall, the study indicates that seaweed enrichment mainly influenced the physicochemical and sensory characteristics of plant-based cheese alternatives. Full article

Background: Fosfomycin (FOS) is an older antimicrobial agent newly rediscovered as a possible treatment for infections with limited therapeutic options (e.g., Gram-negative bacteria with difficult-to-treat resistance, DTR), especially in intravenous form. However, for correct usage of FOS, it is necessary to have a reliable susceptibility testing method suitable for routine practice and robust interpretation criteria. Results: The results were interpreted according to 2023 interpretation criteria provided by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). DTR Gram-negatives were more likely to be resistant to FOS (45% in Enterobacterales and 20% in P. aeruginosa) than non-DTR (10% and 6.7%, resp.). All isolates of S. aureus were susceptible to FOS. In Gram-negatives, all agreement values were unacceptable. Etest^® performed better in the DTR cohort (categorical agreement, CA, 80%) than in the non-DTR cohort (CA 45.7%). There were no very major errors (VREs) observed in P. aeruginosa. S. aureus had surprisingly low essential agreement (EA) rates (53% for MRSA and 47% for MSSA) for Etest^®, but categorical agreement was 100%. Methods: A total of 130 bacterial isolates were tested and compared using the disc diffusion method (DD) and gradient strip method (Etest^®) with the reference method (agar dilution, AD). The spectrum of isolates tested was as follows: 40 Enterobacterales (20 DTR vs. 20 non-DTR), 30 Pseudomonas aeruginosa (15 DTR vs. 15 non-DTR), and 60 Staphylococcus aureus (30 methicillin-susceptible, MSSA, vs. 30 methicillin-resistant, MRSA). Conclusions: Neither one of the tested methods was identified as a suitable alternative to AD. It would be beneficial to define more interpretation criteria, at least in some instances. Full article

In order to impart the properties of cementitious material to the Tibetan Agar soil, two high-temperature activation mechanisms (HTMA, HTMB) were designed in this study, and the products and hydration-hardening properties of Tibetan Agar soil high-temperature activation mechanism were analyzed by means of SEM, XRD, and XRF. The results show that the main components of Tibetan Aga soil are calcite and quartz; Aga soil is activated by HTMA high-temperature activation, forming the main products of CaO, C₂S, CaSiO₃, and CaAl₂Si₂O₈, and its products have both air-hardening and water-hardening characteristics; Aga soil is activated by HTMB high-temperature activation, and when the temperature reaches 1250 °C when the clinker is not found in the CaO, the generation of C₂S, C₃S, C₃A, C₄AF, and Mg₂SiO₄ minerals with good water-hardening cementitious properties occurs when the temperature rises to 1350 °C, although the formation of some inert minerals that do not have the cementitious properties, but this temperature activation products of the thermodynamic properties of the best; Enhancing the value of lime saturation degree (KH) and silicon rate (SM) can promote the formation of the products of the C₂S and C₃S, increase the reactivity of the Aga soil activation products, and increase the hydration heat as well as compressive and flexural strength, combined with the results of the hydration heat and mechanical test, KH is recommended to be 0.9~0.94, SM is recommended to be 1.8~2.4, and alumina ratio (IM) is recommended to be 1.8~2.4 when Aga soil is used with raw materials. Full article

Methyl gallate (MG) and gallic acid (GA) are natural compounds with potent activity against methicillin-resistant Staphylococcus aureus (MRSA), a significant global health concern. In this study, MG and GA were incorporated into cellulose acetate (CA) blended with poly(vinyl alcohol) (PVA) to create electrospun nanofibers aimed at combating both methicillin-susceptible S. aureus (MSSA) and MRSA. Key electrospinning parameters—DC voltage, injection flow rate, and syringe tip–collector distance—were optimized, with the best conditions being a 1.5 mL/h flow rate, 30 cm distance, and 20 kV voltage. The resulting nanofiber mats were characterized by SEM, FTIR, DSC, tensile strength testing, contact angle measurement, swelling behavior, and release profiling. Antibacterial properties were assessed using the agar diffusion test. The obtained nanofibers had diameters ranging from 879.33 to 906.13 nm. Among the samples, MG-GA-CA/PVA exhibited the highest tensile strength, good flexibility, and improved stiffness, which was related to enhanced thermal stability and chemical interactions as shown by DSC and FTIR analyses. This formulation also displayed excellent hydrophilicity, swelling properties, and a consistent release profile over 8 to 24 h. Furthermore, MG-GA-CA/PVA showed superior antibacterial activity against both MSSA and MRSA, suggesting its potential as a strong, flexible, and effective anti-S. aureus material. Full article

The aim of the present study was the isolation of high exopolysaccharide (EPS) producers, Lactic Acid Bacteria (LAB) strains, from three types of milk: goat, sheep, and camel milk. Among 112 LAB isolates tested for their ability to produce EPS on MRS-sucrose agar, only 11 strains were able to produce EPS and only three higher producers’ strains were identified by 16S rRNA gene sequencing as two strains of Lactococcus lactis subsp. lactis (SP255, SP257) isolated from camel milk and one strain of Weissella cibaria (SP213) isolated from goat milk. The physicochemical characterization of the purified EPSs revealed a significant sugar yield, with concentrations ranging from 2.17 to 2.77 g/L, while the protein content remained relatively low (0.03 g/L). The UV-visible spectrum showed high Ultra Violet (UV) absorption at 240–280 nm and the Fourier-Transform Infrared (FTIR) spectra showed the presence of a large number of functional groups, including hydroxyl (-OH), carbonyl (-C=O), and methyl groups (-CH3). The EPS solubility indicated their hydrophilic properties and the investigation of interfacial properties indicated that these EPSs could be used as natural emulsifiers and stabilizers in both acidic and neutral emulsions. Moreover, a new type of emulsion system was developed by the utilization of EPSs in the formation of multilayer interfaces in oil-in-water (O/W) emulsions stabilized by sodium caseinate (CAS). Thus, the impact of an EPS addition on the particle size distribution and electrical charge has been studied. At pH 3, the studied EPSs adhered to the surfaces of caseinate-coated droplets and the stability of O/W emulsions was improved by adding certain concentrations of EPSs. The minimum concentration required to stabilize multilayer emulsions for EPSs SP255, EPS SP257, and EPS SP213 was 1.5, 1.5, and 1.7 g/L, respectively. These findings reveal a new EPS with significant potential for industrial use, particularly as an emulsion stabilizer. Full article