Search Results (333)

The complex polysaccharide pullulan is characterized as a glucose-containing biopolymer that is both water-soluble and neutral in polarity. A variety of commercial applications exist for pullulan, including its utilization as a flocculant, a blood plasma substitute, a food additive, a dielectric material, an adhesive, or a packaging film. The fungus Aureobasidium pullulans has used several hydrolysates derived from plant biomass or starch-containing processing coproducts to support polysaccharide production. These include various plant biomass or processing coproduct streams such as lignocellulosic-containing peat, prairie grass, stalks, hulls, straw, shells, and pods or starch-containing coproducts from the processing of corn, rice, jackfruit seeds, palm kernels, cassava, and potatoes. The pullulan concentration produced by A. pullulans and the pullulan content of the polysaccharide depend on the plant hydrolysate carbon content and the strain used. If a lower-cost culture medium for fungal pullulan production were to be developed, a more economical approach to synthesizing commercial pullulan would be the utilization of plant-derived hydrolysates. This review examines the ability of selected hydrolysates of lignocellulosic plant biomass or plant-derived starch-containing processing coproducts to support A. pullulans polysaccharide synthesis in order to identify those substrates with the greatest potential for reducing the cost of commercial pullulan. Full article

The selenium-rich area of the Tibetan Plateau is located in Qinghai Province, China, at an altitude of 2200–2500 m, with selenium content exceeding 0.3 mg/kg. This study focused on the soil selenium content, physicochemical parameters, and microbial communities of selenium-rich soils in the Ping’an selenium-rich area, as part of the Tibetan Plateau. The results showed that the total selenium contents in both the Ping’an and Guide areas were significantly higher than in the control, ranging from 624.56 µg/kg to 727.48 µg/kg in Ping’an and reaching 721.74 µg/kg in Guide. Correlation analysis revealed that organic selenium content was significantly positively correlated with total phosphorus (p < 0.05), effective phosphorus (p < 0.01), and available potassium (p < 0.05) contents. Within the bacterial community, organic selenium content showed significant positive correlations with the abundance of Arthrobacter crystallopoietes (p < 0.01), Nitrosospira briensis (p < 0.01), and unclassfied Rhodobacteraceae (p < 0.01). Total selenium content was significantly negatively correlated with the abundance of Tepidisphaera mucosa (p < 0.01). RDA analysis indicated that total potassium contributed the most (30.52%), followed by total nitrogen (21.47%) and total phosphorus (15.07%). In the fungal community, organic selenium content was significantly positively correlated with the abundance of Tausonia pullulans (p < 0.01), Botryotrichum domesticum (p < 0.01), Preussia flanaganii (p < 0.05), and Enterocarpus grenotii (p < 0.01). RDA analysis showed that total phosphorus contributed the most (27.30%), followed by total potassium (21.70%) and total nitrogen (14.86%). The findings provide a scientific basis for understanding soil physicochemical properties and microbial diversity in plateau selenium-rich regions and lay a foundation for the isolation and utilization of dominant microbial species in these soils. Full article

This study reports the synthesis and detailed characterization of pullulan-isononanoate (Pull-Iso), as well as the preparation and characterization of Pull-Iso films incorporating liposomes loaded with silibinin (SB) and smoke tree (Cotinus coggygria) extract (STExt), to explore the physicochemical and functional properties of pullulan-based biomaterials for potential biomedical applications. Pullulan was successfully esterified with isononanoic acid chloride, as confirmed by ¹H and ¹³C NMR (Nuclear Magnetic Resonance) and Fourier Transform Infrared (FTIR) spectroscopy. Modification significantly reduced the glass transition temperature (Tg), indicating enhanced chain mobility due to the introduction of bulky side chains. Prepared liposomes, embedding SB and extracted smoke tree compounds, exhibited particle sizes ~2000 nm with moderate polydispersity (~0.340) and zeta potential values around –20 mV, demonstrating lower colloidal stability over 60 days, thereby justifying their encapsulation within films. Optical microscopy revealed uniform liposome dispersion in Pull-Iso film with 0.5 g of liposomes, while higher liposome loading (0.75 g of liposomes) induced aggregation and microstructural irregularities. Mechanical analysis showed a reduction in tensile strength and strain at higher liposome content. The incorporation of liposomes encapsulating STExt and SB significantly enhanced the antioxidant activity of Pull-Iso-based films in a concentration-dependent manner, as demonstrated by DPPH and ABTS radical scavenging assays. These preliminary findings suggest that pullulan esterification and controlled liposome incorporation may enable the development of flexible, bioactive-loaded films, which could represent a promising platform for advanced wound dressing applications, warranting further investigation. Full article

Introduction: Magnetic nanoparticles are widely investigated as multifunctional platforms for drug delivery and theranostic applications, yet their biomedical implementation is hindered by aggregation, limited colloidal stability, and insufficient biocompatibility. Hybrid biopolymer coatings can mitigate these issues while supporting drug incorporation. Aim: This study aimed to develop casein–pullulan-coated Fe₃O₄ nanocomposites loaded with xanthohumol, enhancing stability and enabling controlled release for potential theranostic use. Methods: Fe₃O₄ nanoparticles were synthesized through co-precipitation and incorporated into a casein–pullulan matrix formed via polymer complexation and glutaraldehyde crosslinking. A 3² full factorial design evaluated the influence of casein:pullulan ratio and crosslinker concentration on physicochemical performance. Nanocomposites were characterized for size, zeta potential, morphology, composition, and stability, while drug loading, encapsulation efficiency, and release profiles were determined spectrophotometrically. Molecular docking was performed to examine casein–pullulan interactions. Results: Uncoated Fe₃O₄ nanoparticles aggregated extensively, displaying mean sizes of ~292 nm, zeta potential of +80.95 mV and high polydispersity (PDI above 0.2). Incorporation into the biopolymer matrix improved colloidal stability, yielding particles of ~185 nm with zeta potentials near –35 mV. TEM and SEM confirmed spherical morphology and uniform magnetic core incorporation. The optimal formulation, consisting of a 1:1 casein:pullulan ratio with 1% glutaraldehyde, achieved 5.7% drug loading, 68% encapsulation efficiency, and sustained release of xanthohumol up to 84% over 120 h, fitting Fickian diffusion (Korsmeyer–Peppas R² = 0.9877, n = 0.43). Conclusions: Casein–pullulan hybrid coatings significantly enhance Fe₃O₄ nanoparticle stability and enable controlled release of xanthohumol, presenting a promising platform for future targeted drug delivery and theranostic applications. Full article

The food packaging industry is undergoing a paradigm shift from conventional petroleum-based materials toward sustainable biopolymer-based alternatives that offer enhanced functionality beyond mere containment and protection. This comprehensive review examines recent advances in the development of active and intelligent food packaging systems utilizing natural biopolymers including polysaccharides, proteins, and their composites. The integration of antimicrobial agents, natural colorimetric indicators, nanofillers, and advanced fabrication techniques has enabled the creation of multifunctional packaging materials capable of extending shelf life, monitoring food quality in real-time, and reducing environmental impact. This review organizes the current research on starch, chitosan-, cellulose-, pectin-, bacterial cellulose-, pullulan-, gelatin-, zein-, and dextran-based packaging systems, with particular emphasis on their physicochemical properties, functional performance, and practical applications for preserving various food products, including meat, fish, fruits, and other perishables. The challenges associated with mechanical strength, water resistance, scalability, and commercial viability are critically evaluated alongside emerging solutions involving chemical modifications, nanocomposite formulations, and innovative processing technologies. Future perspectives highlight the need for standardization, life cycle assessments, regulatory frameworks, and consumer acceptance studies to facilitate the transition from laboratory innovations to industrial-scale implementation of sustainable biopolymer packaging solutions. Full article

Microbial polysaccharides are promising components for wound-care products. This study reports the development of wound-healing antimicrobial hydrogels, based on pullulan from Aureobasidium pullulans, combined with mesenchymal cell-derived conditioned medium. Structural characterization of pullulan was confirmed by FTIR and NMR. Twenty-three formulations containing pullulan, chitosan, gelatin, citric acid, and antimicrobial agents were prepared. Physicochemical screening identified optimal hydrogels: No. 22 (1.2% pullulan, 1.2% chitosan, 0.2% citric acid, 2.4% gelatin, 0.1% conditioned medium, 0.4% glutaraldehyde) and No. 23 (2.4% pullulan, no chitosan, the remaining components identical to those in No. 22). Both exhibited pH values of 5.34 and 5.49, moisture content of 92%, swelling capacities of 175% and 213%, and dynamic viscosity between 58–120 mPa·s. Cytotoxicity testing with human mesenchymal stem cells showed no significant toxicity, with both hydrogels supporting cell adhesion and proliferation. Antimicrobial assays demonstrated inhibitory activity against Staphylococcus aureus and Escherichia coli for both formulations; only hydrogel No. 23 inhibited Pseudomonas aeruginosa. In vitro scratch assays revealed that hydrogel No. 23 significantly promoted fibroblast migration, achieving 30.25% scratch closure after 24 h. The developed formulations combine favorable physicochemical properties with antimicrobial efficacy and regenerative potential, supporting further evaluation as advanced wound-healing and anti-burn dressings. Full article

Extremotolerant fungi inhabit environments with multiple overlapping stressors, yet most studies examine stresses individually. We tested whether preconditioning with salt, cold, or both improves survival after desiccation and freezing, and whether combined salinity and temperature effects on growth are additive or synergistic. We studied Aureobasidium pullulans, Aureobasidium subglaciale, Aureobasidium melanogenum, and Hortaea werneckii (haploid and diploid). All preconditioning treatments significantly increased long-term desiccation survival in A. pullulans, reflecting its generalist capacity to activate cross-protective responses. H. werneckii displayed smaller improvements, consistent with a specialist strategy. Freezing survival without cryoprotectants remained ~100% in both species, indicating high intrinsic tolerance. Growth analyses revealed synergistic effects of salinity and temperature in Aureobasidium spp. Species differed in salinity sensitivity (A. melanogenum > A. pullulans > A. subglaciale) and thermal preferences. A. melanogenum and A. pullulans grew faster at higher temperatures, while A. subglaciale showed the opposite trend. In H. werneckii, salinity governed growth. Haploids slowed as salinity increased, while the diploid remained unaffected. This is the first confirmation of the long-standing suggestion that hybrid diploid genomes of many H. werneckii are an adaptation to osmotic stress. These findings illustrate two pathways to extremotolerance: inducible flexibility in Aureobasidium versus constitutive halotolerance in H. werneckii. Full article

Background/Objectives: Breast cancer remains one of the leading causes of cancer-related mortality. Still, limited drug delivery systems for genistein, a powerful natural anticancer agent, draw significant attention. We aimed to develop a co-therapeutic/synergistic dual-compartment system; genistein-loaded pumpkisome nanovesicles (GNS-PKs) incorporated into pullulan microneedle patches (MNs), and to explore its anticancer activity. Methods: GNS-PKs were prepared and characterized for particle size (P.S), polydispersity (PDI), zeta potential (Z.P), encapsulation efficiency (E.E%), and stability. Afterward, they were embedded in pullulan-dissolving microneedle arrays and characterized for release kinetics, mechanical strength, and in vitro cytotoxicity. The in vivo efficacy was evaluated in mice with solid Ehrlich Ascites Carcinoma (EAC), focusing on tumor volume, oxidative stress, inflammatory cytokines, Epidermal Growth Factor (EGFR) expression biomarkers, and histopathological analysis. Results: The optimized nanovesicles had a particle size of 170 nm, a zeta potential of −42 mV, and an entrapment efficiency of up to 92%. Pullulan microneedles demonstrated significantly high mechanical strength and effective deep penetration. In addition to, it markedly decreased MCF-7 cellular viability (IC₅₀ = 3.5 µg/mL). Besides, it had a 76% reduction in tumor volume, significantly increased the antioxidant activity (SOD, CAT, GSH), decreased the levels of inflammatory biomarkers (IL-6, COX-2, NF-κB), and markedly downregulated the EGFR expression (p < 0.0001). Histological study revealed decreased mitotic activity and large tumor cells, with minimal systemic damage. Conclusions: GNS-PKs-pullulan microneedle system offers a hope for an innovative, potent, effective, and non-invasive strategy for breast cancer treatment with high antitumor efficacy. Full article

This study presents an energy-efficient, room-temperature synthesis and characterization of methacrylated pullulan (Pull-MA) hydrogel developed for controlled nutrient delivery in agricultural applications. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) analyses confirmed the successful functionalization of pullulan with methacrylate groups, accompanied by a decrease in thermal transition temperatures, indicative of increased polymer chain mobility. The synthesized Pull-MA hydrogel exhibited a high swelling capacity, reaching an equilibrium swelling ratio of 1068% within 5 h, demonstrating its suitability as a carrier matrix. The room-temperature synthesis approach enabled the in situ incorporation of microbial inoculant into the hydrogel network, preserving microbial viability and activity. SEM analysis performed under the different magnifications (1000, 2500, 5000, 10,000, 25,000×) has confirmed brittle nature of xerogels and increasing in structural irregularities with increasing in cultivation broth content.The biological performance of the fertilizer-loaded hydrogels was evaluated through seed germination assays using maize and pepper as model crops. The optimized formulation, T2 (Pull-MA: cultivation broth 1:5 w/w), significantly improved germination efficiency, as evidenced by increased relative seed germination (RSG), root growth rate (RRG), and germination index (GI) compared to both the control and the low-fertilizer formulation (T1, 1:2.5 w/w). These findings highlight the potential of Pull-MA hydrogels as bioactive seed-coating materials that enhance early seedling development through controlled nutrient release. The results lay a solid foundation for further optimization and future application of this system under real field conditions. Full article

This study aimed to develop and characterize an eco-friendly facial mask based on the pullulan biopolymer incorporating grape seed flour extract, a sustainable source of polyphenols. The extract was characterized by its phenolic content, antioxidant capacity, enzyme inhibition and antimicrobial activity. High total phenolic and flavonoid contents, along with the presence of trans-resveratrol, conferred strong antioxidant activity. The extract effectively inhibited tyrosinase and elastase enzymes, indicating its anti-aging potential, and exhibited antimicrobial effects particularly against Staphylococcus aureus. The incorporation of the extract in pullulan films increased thickness and coloration while maintaining transparency and improving barrier properties. The bioactive films showed strong antioxidant activity and displayed selective antibacterial activity against S. aureus, including MRSA strains. A facial mask prototype was successfully produced, demonstrating flexibility, solubility, and potential for topical applications. Overall, the developed pullulan–grape seed extract films exhibit multifunctional cosmeceutical potential combining antioxidant, antimicrobial, and anti-aging effects with sustainable valorization of wine industry by-products. Full article

This study investigates electrospinning methodologies using distilled water as an environmentally friendly and non-toxic solvent for fabricating nanofibers composed of fish collagen (COL) and pullulan (PUL). The underlying hypothesis is that incorporating PUL will enhance the spinnability of the electrospun solution through the formation of hydrogen bonds with COL, thereby facilitating improved fiber development within an aqueous system. This study examined the interactions between COL and PUL molecules, focusing on hydrogen bonding and the consequential alterations in secondary structural conformation, to elucidate their effects on the spinnability and stability of COL in water-based solutions. Furthermore, this study emphasizes the advantages of needle-free electrospinning, which enables the efficient production of nanofibers and offers scalability potential for industrial applications. The architecture and properties of the resultant ultra-thin COL/PUL fibers were comprehensively characterized, underscoring their suitability for various biomedical applications. The development of PUL-based skin nanofibers represents a significant advancement in the field of biomaterials, offering a biocompatible and biodegradable alternative for dermatological applications, including skin regeneration, wound healing, drug delivery, tissue engineering, and cosmetic science. The benefits of needle-free electrospinning, such as enhanced production efficiency and scalability, are particularly emphasized, demonstrating its potential for the large-scale commercial manufacturing of biocompatible nanofibers. This study aimed to address the research gap regarding the use of distilled water as an eco-friendly and safe solvent for electrospinning nanofibers made from collagen and pullulan. This study aimed to investigate the unexplored potential of distilled water for this application. Full article

Extreme environments are a largely unexplored reservoir of microbial diversity, with a remarkable potential to be exploited in agriculture. One hundred and seventeen yeast isolates, derived from different ecosystems in Italy, Sweden, Algeria, and France, were molecularly identified, and the most represented genus was Aureobasidium (57%). A phylogenetic analysis based on a multi-locus sequence typing (ITS, ELO, EF-1alpha) was conducted to characterize the black yeasts’ population. To investigate A. pullulans extremophilic and extremotolerant behaviour, different temperatures and pH, together with the enzymatic production, were evaluated. The strains were tested by in vitro and in vivo assays against the postharvest fungal pathogen Monilinia fructicola as potential biocontrol agents (BCAs). Results displayed a great ecological variability concerning strains’ growth and cell production depending on different culture conditions. However, a remarkable thermotolerance aptitude was detected in almost all the strains. In particular, the strains belonging to Group 2 (Algerian Desert) and 3 (Alto Adige Region) showed, respectively, higher thermotolerance and biocontrol ability. These findings showed how some extreme environments could represent a promising source for new potential BCAs. However, further studies are needed to investigate the mechanisms of action of these putative BCAs for application during the postharvest phase. Full article

Luteolin is a naturally occurring flavonoid with growing interest for its senolytic properties. However, its poor water solubility and low bioavailability limit clinical application. This study aimed to develop and compare two types of nanocarriers, liposomes and polymeric nanoparticles, for the efficient delivery of luteolin in senolytic therapies. Liposomes with luteolin were prepared using the lipid film hydration method, followed by sonication and extrusion. Polymeric nanoparticles were developed via the nanoprecipitation method using pullulan acetate, a hydrophobic derivative obtained by chemical functionalization of pullulan. Pullulan was biosynthesized over 72 h using the microorganism Aureobasidium pullulans ICCF 36 (from CMII–INCDCF-ICCF). The formulation used a polymer-to-luteolin ratio of 10:1 (g/g) and Pluronic F127 as a stabilizer. Nanoprecipitation was carried out under controlled conditions: stirring at 700 rpm and dropwise addition at 0.5 mL/min. Luteolin was successfully encapsulated in both delivery systems. Liposomes showed an encapsulation efficiency of 85.07 ± 0.09% and nanoscale diameter. Polymeric nanoparticles demonstrated an encapsulation efficiency of 74.87 ± 0.05%, nanometric size and a formulation yield of 73.29 ± 0.09%. Both liposomal and polymeric nanoparticle systems effectively encapsulated luteolin, with high efficiency and yield. The formulations present promising potential for use in senolytic therapies, targeting age-related cellular dysfunction. Further studies will assess their release kinetics, biological activity, and senolytic effects in vitro and in vivo. Full article

This study aims to enhance the oxidative stability of fish oil through encapsulation in pullulan/sodium caseinate (PUL/NaCAS) nanofibers. Electrospinning was employed to produce three formulations: control (0% fish oil) and samples with 5% and 10% fish oil. Characterization of the emulsions showed that increasing oil content led to larger droplet size and reduced viscosity. Scanning electron microscopy (SEM) analysis revealed surface imperfections and a gradual increase in fiber diameter with higher oil loading. Fourier transform infrared (FTIR) spectroscopy confirmed molecular interactions, and fibers with 10% fish oil showed a shift toward a more amorphous structure. Fish oil incorporation also enhanced hydrophobicity and thermal stability, as indicated by thermal and wettability measurements. Antioxidant assays include 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and total phenolic content (TPC), which showed the highest bioactivity at 5% fish oil, with a slight decrease at 10%, likely due to structural saturation. Encapsulation at 5% fish oil significantly reduced lipid oxidation during storage (hydroperoxide values decreased from 8.6 to 4.8 mM at 60 °C/15 days), demonstrating the protective effect of the nanofiber matrix. Docking and density functional theory (DFT) analyses confirmed stable DHA/EPA–caseinate interactions and increased electronic stability, supporting the experimental results. Compared with conventional carriers such as spray-dried or maltodextrin-based systems, PUL/NaCAS nanofibers offered superior oxidative stability, bioactivity, and a biodegradable matrix. Overall, the 80PUL:20NaCAS:5% fish oil formulation represents a versatile platform for stabilizing omega-3 oils, with potential applications in food preservation, nutraceutical delivery, and functional packaging. Full article

In this study, the electrospinning technique was employed to encapsulate mountain germander (MG) polyphenolic extract into pullulan/zein (PUL:ZE) delivery systems stabilized with sunflower lecithin. The rheological and physical properties of the pullulan (PUL), PUL:ZE, and zein (ZE) polymer solutions were evaluated to assess their electrospinnability potential. Fabricated nanofibers were then characterized for their morphology, physicochemical, and thermal properties, as well as encapsulation efficiency and simulated in vitro digestion. The elastic component of the polymer solution, quantified by the Deborah number, showed a strong correlation with nanofiber diameter (r = 0.75). FT-IR spectra confirmed the role of sunflower lecithin as a mediator in the formation of hydrogen and hydrophobic interactions among PUL, ZE, and polyphenols. The circular dichroism spectra confirmed the influence of the MG extract on the change in the secondary conformation of the protein structure. The PUL:ZE delivery matrix proved to be suitable for the retention of phenylethanoid glycosides (encapsulation efficiency > 73%). The formulation 50PUL:50ZE was found to have the highest potential for prolonged release of polyphenols under gastrointestinal in vitro conditions. These findings propose a water-based electrospinning approach for designing polyphenolic delivery systems stabilized with lecithin for potential applications in active food packaging or nutraceutical products. Full article