Search Results (210)

The majority of studies of fungal utilization of chitosan are associated with the production of a specific enzyme, chitosanase, which catalyzes the hydrolytic cleavage of the macrochain. In our opinion, the development of approaches to obtaining materials with new functional properties based on non-destructive chitosan transformation by living organisms and their enzyme systems is promising. This study was conducted using a wide range of classical and modern methods of microbiology, biochemistry, and physical chemistry. The ability of the ascomycete Fusarium oxysporum Schltdl. to modify films of chitosan with average-viscosity molecular weights of 200, 450, and 530 kDa was discovered. F. oxysporum was shown to use chitosan as the sole source of carbon/energy and actively overgrew films without deformations and signs of integrity loss. Scanning electron microscopy (SEM) recorded an increase in the porosity of film substrates. An analysis of the FTIR spectra revealed the occurrence of oxidation processes and crosslinking of macrochains without breaking β-(1,4)-glycosidic bonds. After F. oxysporum growth, the resistance of the films to mechanical dispersion and the degree of ordering of the polymer structure increased, while their solubility in the acetate buffer with pH 4.4 and sorption capacity for Fe²⁺ and Cu²⁺ decreased. Elemental analysis revealed a decrease in the nitrogen content in chitosan, which may indicate its inclusion into the fungal metabolism. The film transformation was accompanied by the production of extracellular hydrolase (different from chitosanase) and peroxidase, as well as biosurfactants. The results obtained indicate a specific mechanism of aminopolysaccharide transformation by F. oxysporum. Although the biochemical mechanisms of action remain to be analyzed in detail, the results obtained create new ways of using fungi and show the potential for the use of Fusarium and/or its extracellular enzymes for the formation of chitosan-containing materials with the required range of functional properties and qualities for biotechnological applications. Full article

Biogenic silver nanoparticles (AgNPs) were synthesized via a green chemistry strategy using wheat extract and subsequently functionalized with a carboxymethyl chitosan–cinnamaldehyde (CMC=CIN) conjugate through covalent imine bonding. The resulting nanohybrid (AgNP–CMC=CIN) was extensively characterized to confirm successful biofunctionalization: UV–Vis spectroscopy revealed characteristic cinnamaldehyde absorption peaks; ATR-FTIR spectra confirmed polymer–terpene bonding; and TEM analysis evidenced uniform nanoparticle morphology. Dynamic light scattering (DLS) measurements indicated an increase in hydrodynamic size upon coating (from 59.46 ± 12.63 nm to 110.17 ± 4.74 nm), while maintaining low polydispersity (PDI: 0.29 to 0.27) and stable surface charge (zeta potential ~ −30 mV), suggesting colloidal stability and homogeneous polymer encapsulation. Antifungal activity was evaluated against Fusarium oxysporum, Penicillium citrinum, Aspergillus niger, and Aspergillus brasiliensis. The minimum inhibitory concentration (MIC) against F. oxysporum was significantly reduced to 83 μg/mL with AgNP–CMC=CIN, compared to 708 μg/mL for uncoated AgNPs, and was comparable to the reference fungicide tebuconazole (52 μg/mL). Seed priming with AgNP–CMC=CIN led to improved germination (85%) and markedly reduced fungal colonization, while maintaining a favorable phytotoxicity profile. These findings highlight the potential of polysaccharide-terpene-functionalized biogenic AgNPs as a sustainable alternative to conventional fungicides, supporting their application in precision agriculture and integrated crop protection strategies. Full article

A fungal strain with comparably high chitosan yield was isolated from the Shivaganga hills and identified as Aspergillus versicolor AD07 through molecular characterization. Later, the strain was cultivated on Sabouraud Dextrose Broth (SDB) and wild jackfruit-based media to evaluate its potential for chitosan production. Among the various media formulations, the highest chitosan yield (178.40 ± 1.76 mg/L) was obtained from the jackfruit extract medium with added peptone and dextrose. The extracted chitosan was characterized through FTIR, XRD (reported a crystallinity index of 55%), TGA/DTG, and DSC analysis, confirming the presence of key functional groups and high thermal resistance. The extracted chitosan was fabricated into a sheet incorporated with 1% lemongrass oil; the sheet exhibited strong antibacterial activity against Escherichia coli (30 mm) and Bacillus megaterium (48 mm). The biodegradation studies reported a weight loss of 38.93 ± 0.51% after 50 days of soil burial. Further, the chitosan film was tested as a packaging material for paneer, demonstrating better preservation by maintaining nutritional quality and reducing microbial load over a 14-day storage period. These findings highlight the potential of A. versicolor AD07-derived chitosan, cultivated on a waste substrate medium, as a sustainable biopolymer for food packaging applications. Full article

Background/Objectives: There is an increasing incidence of fungal infections in conjunction with the rise in resistance to medical treatment. Antimicrobial resistance is frequently associated with virulence factors such as adherence and the capacity of biofilm formation, which facilitates the evasion of the host immune response and resistance to drug action. Novel therapeutic strategies have been developed to overcome antimicrobial resistance, including the use of different type of nanomaterials: metallic (Au, Ag, Fe₃O₄ and ZnO), organic (e.g., chitosan, liposomes and lactic acid) or carbon-based (e.g., quantum dots, nanotubes and graphene) materials. The objective of this study was to evaluate the action of nanoparticles of different synthesis and with different coatings on fungi of medical interest. Methods: Literature research was conducted using PubMed and Google Scholar databases, and the following terms were employed in articles published up to June 2025: ‘nanoparticles’ in combination with ‘fungal biofilm’, ‘Candida biofilm’, ‘Aspergillus biofilm’, ‘Cryptococcus biofilm’, ‘Fusarium biofilm’ and ‘dermatophytes biofilm’. Results: The utilization of nanoparticles was found to exert a substantial impact on the reduction in fungal biofilm, despite the presence of substantial variability in minimum inhibitory concentration (MIC) values attributable to variations in nanoparticle type and the presence of capping agents. It was observed that the MIC values were lower for metallic nanoparticles, particularly silver, and for those synthesized with polylactic acid compared to the others. Conclusions: Despite the limited availability of data concerning the stability and biocompatibility of nanoparticles employed in the treatment of fungal biofilms, it can be posited that these results constitute a significant initial step. Full article

Honey, propolis or royal jelly are considered natural remedies with therapeutic properties since antiquity. Many papers explore the development of antimicrobial biomaterials based on individual bee products, but there is a lack of studies on their synergistic effects. Combining honey, propolis and royal jelly with silver nanoparticles in a biopolymer matrix offers a synergistic strategy to combat antibiotic-resistant bacterial infections. This approach supports progress in wound healing, soft tissue engineering and other domains where elimination of the microorganisms is needed like food packaging. In this study we have obtained antimicrobial films based on bee products and silver nanoparticles (AgNPs) incorporated in an alginate–chitosan blend. The novel biomaterials were analyzed by UV-Vis, fluorescence and FTIR spectroscopy or microscopy, SEM and thermal analysis. Antibacterial tests were conducted against both Gram-positive and Gram-negative bacteria, while the antifungal properties were tested against Candida albicans. The diameters for growth inhibition zones were up to 10 mm for bacterial strains and 8 mm for the fungal strain. Additionally, cytotoxicity assays were performed to evaluate the biocompatibility of the materials, the results indicating that the combination of honey, propolis, royal jelly and AgNPs does not produce synergistic toxicity. Full article

Apple pomace, a by-product from the production of concentrated juice, is a major contributor to global food waste. Despite its beneficial nutritional profile, apple pomace is predominantly disposed of in landfills. Rapid fermentation and spoilage caused by microorganisms are compounding factors in this demise, despite significant research into upcycling strategies. Thus, there is an unmet need for economical approaches that allow for the preservation of pomace during storage and transportation to centralized processing facilities from regional hubs. To address this challenge, we investigated the potential of different preservatives for preventing microbial growth and the spoilage of apple pomace, including antimicrobials (natamycin and iodine), polysaccharides (chitosan and fucoidan), and acetic acid. Spread plates for total microbial and fungal counts were employed to assess the effectiveness of the treatments. High concentrations (10,000 ppm) of chitosan were effective at reducing the microbial load and inhibiting growth, and in combination with antimicrobials, eliminated all microbes below detectable levels. Nevertheless, acetic acid at an equivalent concentration to commercial vinegar displayed the highest economic potential. Apple pomace submerged in 0.8 M acetic acid (3 kg pomace per liter) resulted in a five-log reduction in the microbial colony-forming units (CFUs) out to 14 days and prevented fermentation and ethanol production. These results provide a foundation for the short-term storage and preservation of apple pomace that could contribute to its upcycling. Full article

Candida auris is an emerging multidrug-resistant fungal pathogen with a high affinity for skin colonization and significant potential for nosocomial transmission. This study aimed to develop and evaluate chitosan-based hydrogels loaded with nystatin and propolis as a topical antifungal strategy for skin decolonization of C. auris. The formulations were selected based on our previous results and optimized for cutaneous application. The internal structure of the hydrogels was investigated by polarized light microscopy, confirming the amorphous nature of propolis and the partial dispersion of nystatin. The antifungal activity was assessed against ten fluconazole-resistant C. auris strains. The CS-NYS-PRO1 formulation demonstrated the highest antifungal performance in the agar test, also reducing viable cell counts to undetectable levels within 6 h. Time–kill assays and SEM imaging confirmed the rapid fungicidal effect and revealed severe membrane disruption and cytoplasmic leakage. Molecular docking analyses indicated the strong binding of nystatin to both sterol 14α-demethylase (CYP51) and dihydrofolate reductase (DHFR) from C. auris, suggesting complementary membrane and intracellular mechanisms of action. These findings support the use of such hydrogels as a local, non-invasive, and biocompatible strategy for managing C. auris colonization, with promising implications for clinical use in infection control and the prevention of skin-mediated transmission in healthcare settings. Full article

This study reports, for the first time, the successful application of chitosan oligosaccharide (COS) and 2-hydroxyethyl cellulose (HEC) coatings on electrospun poly(3-hydroxybutyrate) (PHB) materials for the immobilization of non-conventional yeast strains with fungal biocontrol potential. The coatings enhanced the surface wettability of PHB fibers, facilitating efficient yeast adhesion and viability maintenance. Among the tested strains, Pichia acaciae YD6 was newly isolated and characterized, while Pichia fermentans YP6 and Zygosaccharomyces bailii YE1 had previously been identified as endophytic colonizers. All three strains demonstrated high adaptability, efficient immobilization, and antagonistic activity, confirming their potential for biocontrol applications. COS-coated PHB fibers promoted greater colony expansion than those coated with HEC. Antifungal assays of the yeast-containing biocarriers showed significant inhibition of F. graminearum growth. These findings underscore the potential of PHB-based fibrous materials as sustainable, bioactive carriers for yeast immobilization, with desirable biological properties. This approach offers a promising and eco-friendly strategy for pest control and bioactive agent delivery in agricultural applications. Full article

This study is an effort to optimize the thermal properties of refined, bleached, and deodorized (RBD) oil by incorporating bionanoparticles. This study investigates the impact on thermal conductivity and thermal diffusivity by incorporating chitosan nanoparticles (CS-NPs) at different temperatures with varying weight fractions of NPs. To the best of our knowledge, these synthesized CS-NPs from oyster mushrooms (Pleurotus ostreatus) and commercial marine-sourced CS-NPs are used for the first time to prepare nanofluids. These nanofluids offer high potential for industrial applications due to their biodegradability, biocompatibility, and nontoxicity. Fungal-sourced chitosan is a vegan-friendly alternative and does not contain allergic compounds, such as marine-sourced chitosan. The CS-NPs were synthesized using a chemical and mechanical treatment process at three different amplitudes, and CS-NPs at amplitude 80 were selected to prepare the nanofluid. Chitin, chitosan, and CS-NPs were characterized by the FTIR-ATR method, while the size and morphology of the CNs were analyzed by SEM. Thermal conductivity and thermal diffusivity of nanofluids and base fluid were measured using a multifunctional thermal conductivity meter (Flucon LAMBDA thermal conductivity meter) by ASTM D7896-19 within the temperature range 40–160 °C with step size 20. The thermal conductivity values were compared between commercial CS-NPs and synthesized CS-NPs treated with RBD palm olein with different weight percentages (0.01, 0.05, and 0.1 wt.%). It was confirmed that the thermal properties were enhanced in both kinds of nanoparticles added to RBD palm olein, and higher enhancement was observed in fungal-sourced CS-NPs treated with RBD palm olein. Maximum enhancement of thermal conductivity of commercial and synthesized CS-NPs treated with RBD palm olein were 4.28% and 7.33%, respectively, at 0.05 wt.%. Enhanced thermal conductivity of RBD palm olein by the addition of CS-NPs facilitates more effective heat transfer, resulting in quicker and more consistent cooking and other potential heat transfer applications. Full article

Citrus fruits are major economic and nutritional crops that are sometimes subjected to serious attacks by many fungal phytopathogens after harvesting. In this study, we focus on the structures of potential antifungal nanocomposites from artichoke leaf extract (Art), Art-mediated nanosilver (AgNPs), and their nanoconjugates with chitosan nanoparticles (Cht) to eradicate the blue mold fungus (Penicillium italicum) and preserve oranges during storage via nanocomposite-based edible coatings (ECs). The biosynthesis and conjugation of nanomaterials were verified using UV and infrared (FTIR) spectroscopy, electron microscopy (TEM and SEM) analysis, and DLS assessments. Art could effectually biosynthesize/cap AgNPs with a mean size of 10.35 nm, whereas the average size of Cht was 148.67 nm, and the particles of their nanocomposites had average diameters of 203.22 nm. All nanomaterials/composites exhibited potent antifungal action toward P. italicum isolates; the Cht/Art/AgNP nanocomposite was the most effectual, with an inhibition zone of 31.1 mm and a fungicidal concentration of 17.5 mg/mL, significantly exceeding the activity of other compounds and the fungicide Enilconazole (24.8 mm and 25.0 mg/mL, respectively). The microscopic imaging of P. italicum mycelia treated with Cht/Art/AgNP nanocomposites emphasized their action for the complete destruction of mycelia within 24 h. The orange (Citrus sinensis) fruit coatings, with nanomaterial-based ECs, were highly effectual for preventing blue mold development and preserved fruits for >14 days without any infestation signs; when the control infected fruits were fully covered with blue mold, the infestation remarks covered 12.4%, 5.2%, and 0% of the orange coated with Cht Art/AgNPs and Cht/Art/AgNPs. The constructed Cht/Art/AgNP nanocomposites have potential as effectual biomaterials for protecting citrus fruits from fungal deterioration and preserving their quality. Full article

Microalgae–fungal pellets (MFPs) effectively degrade pollutants in high-density aquaculture wastewater; however, their structural instability limits their long-term applicability. This study evaluated the effects of three crosslinking agents, sodium alginate (SA), chitosan (CTS), and polyvinyl alcohol (PVA), on enhancing the stability of MFPs. The results demonstrated that the initial 20 g/L SA-crosslinked MFP sample (SMFP₀) exhibited significantly improved structural stability, maintaining superior mechanical hardness (57.05 g) after 9 days. Further analysis revealed that SMFP₀ exhibited a more negative absolute Zeta potential (−13.05 mV), increased fluorescence intensity (0.020) in its tightly bound extracellular polymeric substances (TB-EPSs), and significantly higher protein (PN, 64.22 mg/L) and polysaccharide (PS, 56.99 mg/L) concentrations compared with the control (p < 0.05). These findings suggest that SMFP₀ possesses physicochemical properties that are conducive to microalgae–fungal aggregation. A scanning electron microscopy (SEM) analysis confirmed that the SA gel network enhanced the system’s stability by strengthening the microalgae–fungal interfacial adhesion and maintaining a porous, light-permeable structure. In practical wastewater treatment, SMFP₀ achieved superior removal rates for COD (84.19%), ammonia nitrogen (95.29%), total nitrogen (89.50%), and total phosphorus (93.46%) compared with non-crosslinked MFPs (p < 0.05). After 9 days of continuous operation (SMFP₉), the pollutant removal efficiencies remained comparable to those observed in the initial stage of the non-crosslinked system, indicating improved structural durability for extended practical application. Full article

Drought and metal pollution severely impact plant growth. Root-associated extremophilic fungi can improve plant performance, and their encapsulation improves protection and effectiveness. This study optimized the encapsulation conditions for an extremophilic fungus with plant growth-promoting traits using alginate–chitosan capsules. An endophytic fungus was isolated from the roots of Neltuma chilensis from the Atacama Desert and identified via internal transcribed spacer (ITS) sequencing. Its plant growth-promoting traits, including exopolysaccharide, ammonium, siderophore, and indole acetic acid production and phosphorus solubilization, were evaluated. Freeze-dried Penicillium nalgiovense was encapsulated using jet-breaking extrusion, and capsule morphology and fungal survival were assessed via scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM), and viability tests. Using Taguchi’s design, optimal conditions for sphericity (0.914 ± 0.002) and mean size (3.232 ± 0.087 mm) were achieved with 1% chitosan, a 5 cm distance to the gelation bath, and a 40 Hz vibration frequency. CLSM analysis confirmed the presence of the chitosan outer layer, revealing the capsule’s coating material encapsulating the fungus P. nalgiovense. The encapsulated fungus remained viable across disinfection times, demonstrating effective protection and gradual release. These findings emphasize the need for precise parameter control in fungal encapsulation, providing a basis for developing robust bioinoculants to support plant resilience in extreme environments. Full article

The Colletotrichum genus is one of the ten most relevant pathogenic fungi in the post-harvest sector owing to its high infection rate in tropical fruits; however, the search for alternatives to synthetic fungicides is crucial because of their adverse effects on health and the environment. This study evaluated the efficacy of chitosan (CH), citral (CT), and hexanal (HX) against Colletotrichum asianum, as well as the toxicological potential of these treatments. In in vitro tests, 1.0% CH, 0.03% CT, and 0.06% HX significantly inhibited fungal development in parameters of radial growth, sporulation, fungal biomass, and germination by 78–100% (p < 0.05). Furthermore, the toxicity index was low to moderate for most concentrations using cucumber and tomato seed germination as a study model. Toxicokinetic predictions suggest that CH, CT, and HX molecules do not pose a danger to human consumption, suggesting that they are promising alternatives to chemical fungicides for the control of phytopathogenic fungi. Full article

Fungal diseases represent a significant threat to global agriculture, leading to substantial crop losses and endangering food security worldwide. Conventional chemical fungicides, while effective, are increasingly criticized for their detrimental environmental impacts, including soil degradation, water contamination, and the disruption of non-target organisms. Additionally, the overuse of these fungicides has accelerated the emergence of resistant fungal strains, further challenging disease management strategies. In response to these issues, bio-nanofungicides and nano-biofungicides have emerged as a cutting-edge solution, combining biocompatibility, environmental safety, and enhanced efficacy. These advanced formulations integrate bio-based agents, such as microbial metabolites or plant extracts, with nanotechnology to improve their stability, controlled release, and targeted delivery. Chitosan, silica, and silver nanoparticles were extensively studied for their ability to encapsulate bioactive compounds or because of their outstanding antifungal activity, while minimizing environmental residues. Recent studies demonstrated the potential of nano-based fungicides to address critical gaps in sustainable agriculture, with promising applications in integrated pest management systems. Here, we summarize the last advances in the development of bio-nanofungicides and nano-biofungicides and analyze the main differences between them. In addition, challenges such as large-scale production, regulatory approval, and comprehensive risk assessments are discussed. Full article

In the field, substantial quantities of insect pathogenic fungal conidia (5 × 10¹²/ha) are usually applied for the control of pests. In this regard, attempts are being made to obtain higher yields of conidia to make the process viable. One of the approaches is to induce microcycle conidia (MC) production. In a solid-state fermentation on rice, the SYB-grown inoculum with more pseudomycelia of B. bassiana enhanced MC production almost 5 times compared to the aerial conidia (AC) within 10 days. A chitosan (CNP) and alginate–chitosan (ACNP) nanocoating of MC increased the overall temperature and UV stability. The % cumulative mortalities of Spodoptera litura larvae over 10 d were 83 ± 8.0, 90 ± 5.0, 83 ± 5.0, and 90 ± 6 for AC-, MC-, CNP- coated MC and ACNP-coated MC, respectively. Using probit analysis, the LT₅₀ values were 5.8, 6.0, 7.5, and 6.3 d for AC, MC, CNPs-MC, and ACNPs-MC, respectively. It was observed that chitin deacetylase (CDA) plays a significant role in increasing MC formation. The higher relative proportion of total CDA over chitosanase activity (higher CDA: chitosanase activity ratio) was found to be correlated with the microcycle conidiation. Full article