Search Results (73)

The objective of this study was the evaluation of fungal solid-state fermentation (SSF) for the production of alginate lyase and extraction of uronic acids from Sargassum sp. For this purpose, the fungi Trichoderma asperellum, Aspergillus oryzae, and Rhizopus oryzae were applied (alone or combined) to Sargassum sp. biomass through SSF (10⁷ spores g_biomass⁻¹, 30 °C, and 7 days of treatment). In general, individual SSF with all three fungi degraded the biomass, achieving a marked synergy in the production of cellulase, laminarinase, and alginate lyase activities (especially for the last one). Trichoderma was the most efficient species in producing laminarinase, whereas Rhizophus was the best option for producing alginate lyase. However, when dual combinations were tested, the maximal values of alginate lyase activities were reached (13.4 ± 0.2 IU g_biomass⁻¹ for Aspergillus oryzae and Rhizopus oryzae). Remarkably, uronic acids were the main monomeric units from algal biomass solubilization, achieving a maximum yield of 14.4 mg_uronic g_biomass⁻¹, with the A + R condition being a feasible, eco-friendly alternative to chemical extraction of this monomer. Additionally, the application of all the fungal pretreatments drastically decreased the total phenolic content (TPC) in the biomass from 369 mg L⁻¹ to values around 44–84 mg L⁻¹, minimizing the inhibition for possible subsequent biological processes in which the residual solid can be used. Full article

Peach fruit faces severe postharvest losses due to thin epidermis and susceptibility to Rhizopus stolonifer-induced soft rot. Chemical control risks residue and resistance issues, demanding eco-friendly alternatives. This study elucidated the mechanism by which trans-2-hexenal (E2H) mitigated postharvest soft rot caused by Rhizopus stolonifer in peach (Prunus persica cv. Hujing Milu) fruit. The results demonstrated that E2H treatment significantly delayed lesion expansion by 44.7% and disease incidence by 23.9% while effectively maintaining fruit quality by delaying firmness loss, reducing juice leakage, and suppressing malondialdehyde (MDA) accumulation. E2H treatment upregulated phenylpropanoid pathway gene expression, enhancing key phenylpropanoid metabolism enzymes activities (phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), polyphenol oxidase (PPO), peroxidase (POD)), leading to the increase of total phenolics by 7.9%. E2H treatment analysis revealed significant enhancements in both chitinolytic activity (CHI) and β-1,3-glucanase (GLU) activity by 85.7% and 12.9%, indicating potentiation of the enzymatic defense system. Concurrently, E2H treatment could improve the redox modulation capacity of peach fruits through promoting catalytic efficiency of redox-regulating enzymes, increasing the accumulation of ascorbic acid (AsA) by 8.1%, inhibiting the synthesis of dehydroascorbic acid (DHA) by 18.6%, as well as suppressing the biosynthesis of reactive oxygen species (ROS). These coordinated enhancements in pathogenesis-related proteins (CHI, GLU), phenylpropanoid metabolism activation, and antioxidant systems are strongly associated with E2H-induced resistance against Rhizopus stolonifer, though contributions from other factors may also be involved. Full article

The soybean [Glycine max (L.) Merr.] plays an important role in human and animal nutrition due to its high protein and oil content. The present study was undertaken to determine the effect of different mineral nitrogen (N) rates and inoculation with Bradyrhizobium japonicum bacteria on fungal colonization of the anatomical parts of seeds (APSS) of two soybean cultivars (Aldana and Annushka). Fungi were identified with the use of the macroscopic method and the polymerase chain reaction (PCR) assay. The study demonstrated that fungal colonization was higher on soybeans cv. Annushka than cv. Aldana. The obtained results indicate that fungal colonization intensity was highest in the cotyledons, lower in the seed coat, and lowest in the embryonic axis. The APSS were colonized by pathogenic fungi belonging mostly to the genus Fusarium, as well as saprotrophic fungi represented by Alternaria alternata, Cladosporium cladosporioides, Penicillium spp., and Rhizopus nigricans. Fungal colonization intensity was highest in soybean seeds inoculated with HiStick^®Soy and in control seeds, whereas the number of fungal isolates obtained from the APSS was lower in the remaining treatments: 60 kg N ha⁻¹ + HiStick^®Soy, 30 kg N ha⁻¹ + HiStick^®Soy, Nitragina, and 60 kg N ha⁻¹. In addition, the statistical analysis revealed that fungal abundance and the biodiversity indicators of fungal communities, including relative frequency (Rf), dominance (Y), and species richness (S), differed across the analyzed APSS and years of the study, which indicates that these parameters were significantly influenced by weather conditions. The abundance of pathogenic and saprotrophic fungal species did not differ significantly between the examined soybean cultivars. Spearman’s rank correlation coefficients were calculated to assess the strength of the relationship between weather conditions and the diversity of fungal communities colonizing soybean seeds. The analysis revealed that the development of pathogenic fungi on soybean seeds was determined by temperature and precipitation on 11–30 June and 1–10 August, whereas the prevalence of saprotrophic fungi was influenced only by precipitation on 1–10 and 21–30 July and 1–10 August. The qPCR analysis demonstrated that the colonization of soybean seeds by F. graminearum and P. verrucosum was affected by all experimental factors. Full article

Fungi can degrade grain quality, produce harmful mycotoxins, and hinder germination in the post-harvest stage, resulting in significant economic losses. Ethyl formate (EF) is an efficient and eco-friendly fumigant for controlling pest insects in grains, horticulture, and quarantine treatments. However, there is a lack of research on the antifungal activity of EF and its degradation products on barley seeds. In this study, fifteen fungal species, predominantly Alternaria infectoria, were isolated and identified from seven Australian barley samples. Efficacy results indicated that EF significantly inhibited fungal growth at a commercial concentration of 2.4 mmol/L, except for Penicillium sp. 2, Fusarium chlamydosporum, and Rhizopus arrhizus. To control these EF-tolerant fungal species, the EF concentration was increased to 5 mmol/L, which achieved a 100% inhibition rate. The degradation product of EF, formic acid, effectively inhibited all EF-tolerant fungi, requiring only 0.08 mmol/L in the in vitro study. There were no significant differences in vigor and germination rates in barley treated with EF at concentrations of 2.5, 3.7, and 5 mmol/L. Additionally, EF treatments led to a significant increase in the barley root length from an average of 9.1 cm in the control group to 13.2, 13. 6, and 12.3 cm at 2.5, 3.7, and 5 mmol/L. The findings suggest that EF could be a suitable alternative fumigant to safeguard grain from fungal infestation, particularly in the context of advancing agricultural practices and improving seed germination quality. The degradation compound, formic acid, may contribute significantly to the overall antifungal function of ethyl formate fumigation, particularly in high-humidity environments. Full article

Rice (Oryza sativa L.) is a staple food globally, providing a critical food for the majority of the Asian population. However, it exposes risks during post-harvest storage, threatening substantial losses in rice quality and quantity. Hence, this study developed a cinnamon oil–chitosan:gelatin film (CO–C:G film) with the parameters as the chitosan:gelatin ratio (C:G = 1:1 and 1:2), cinnamon oil (CO) contents (0.75, 1.0, 1.25, 2.5, and 5.0%) and thickness film levels (0.165, 0.183, and 0.287 mm) to inhibit three fungal species, Rhizopus oryzae 01, R. microsporus 01, and Syncephalastrum racemosum 01, and control rice weevil infestation on paddy rice at a variety of water activities, such as 0.71 a_w and 0.95 a_w, at room temperature. The results revealed that at 0.95 a_w, the fungal growth rate and rice weevil’s mortality were impacted significantly by all parameters of the CO–C:G film (p < 0.05). Especially, the CO–C:G film with 1.25% CO and C:G = 1:1 at a thickness film of 0.287 mm inhibited all observed fungi and rice weevils better than the CO–C:G film’s other parameters. The inhibition of the CO–C:G film for these fungi ranged from 66% to 72.6%. Likewise, 80–100% of rice weevils were mortal when paddy rice was treated with the CO–C:G film on the 12th or 15th day of treatment depending on the water activity of paddy rice grains. The findings of this study provide insights for researchers, agricultural experts, and the food industry, highlighting the need to establish effective and sustainable strategies for rice preservation. Full article

We present the case of a 60-year-old immunocompromised man who presented with two pruritic pink–red indurated nodules with overlying scale and focal areas of ulceration on his left dorsal and left medial forearm, which evolved over a 2-month period. The pathology showed numerous fungal hyphae present that were pauci-septate with various branched angles and variable hyphal thickness. Fungal cultures grew Rhizopus species and a universal fungal PCR detected the Rhizopus oryzae complex. Based on the clinicopathologic correlation, the diagnosis of cutaneous mucormycosis was made. Cutaneous mucormycosis is an aggressive fungal infection of the Mucorales family occurring after the inoculation of fungal spores in disrupted skin. It usually presents as a necrotic eschar but can also present as cellulitis that evolves into a necrotic ulcer. A prompt diagnosis is critical for the effective management of cutaneous mucormycosis. The treatment includes an immediate systemic treatment with amphotericin B and a surgical debridement of the necrotic regions. Given the wide range of presenting symptoms, clinical suspicion for this emergent condition must remain high in immunocompromised and diabetic patients. Full article

Certain species of Mucorales have been identified as causative agents of mucormycosis, a rare yet often lethal fungal infection. Notably, these fungi exhibit intrinsic resistance to common azole drugs, which target lipids. Given the pivotal role of lipids in drug resistance and their contribution to innate resistance to azoles, this study provides a comprehensive overview of key lipid classes, including sphingolipids (SLs), glycerophospholipids (GPLs), and sterols, in Rhizopus delemar 99-880, a well-characterized reference strain among Mucorales. Using shotgun lipidomics as well as liquid- and gas-chromatography-based mass spectrometric analyses, we identified the lipid intermediates and elucidated the biosynthetic pathways of SLs, PGLs, and sterols. The acidic SLs were not found, probably because the acidic branch of the SL biosynthesis pathway terminates at α-hydroxy phytoceramides, as evident by their high abundance. Intermediates in the neutral SL pathway incorporated higher levels of 16:0 fatty acid compared to other pathogenic fungi. A strikingly high phosphatidylethanolamine (PE)/phosphatdylcholine (PC) ratio was observed among GPLs. Ergosterol remains the major sterol, similar to other fungi, and our analysis confirms the existence of alternate ergosterol biosynthesis pathways. The total lipidomic profile of R. delemar 99-880 offers insights into its lipid metabolism and potential implications for studying pathogenesis and drug resistance mechanisms. Full article

Live-cell imaging generally requires pretreatment with fluorophores to either monitor cellular functions or the dynamics of intracellular processes and structures. We have recently introduced full-field optical coherence tomography for the label-free live-cell imaging of fungi with potential clinical applications for the diagnosis of invasive fungal mold infections. While both the spatial resolution and technical set up of this technology are more likely designed for the histopathological analysis of tissue biopsies, there is to our knowledge no previous work reporting the use of a light interference-based optical technique for direct mycological examination and monitoring of intracellular processes. We describe the first application of dynamic full-field optical transmission tomography (D-FF-OTT) to achieve both high-resolution and live-cell imaging of fungi. First, D-FF-OTT allowed for the precise examination and identification of several elementary structures within a selection of fungal species commonly known to be responsible for invasive fungal infections such as Candida albicans, Aspergillus fumigatus, or Rhizopus arrhizus. Furthermore, D-FF-OTT revealed the intracellular trafficking of organelles and vesicles related to metabolic processes of living fungi, thus opening new perspectives in fast fungal infection diagnostics. Full article

This study aimed to examine fungi diversity in dried beef meat sold in Ekiti State, characterize the isolated fungi, and determine the aflatoxin-producing ability of the Aspergillus fungi in the samples. Dried beef meat was collected from different markets in Ekiti State and screened for the presence of filamentous fungi using molecular methods. Samples were cultured aseptically on potato dextrose agar (PDA) for fungi isolation, and molecular identification was performed using DNA extraction, Polymerase chain Reaction (PCR), ITS-1/ITS-4 primer pair, and nucleotide sequencing. The results obtained indicated a range of filamentous fungi genera including Aspergillus, Rhizopus, Penicillium, Fusarium, Cladosporium, Alternaria, and other fungi species contaminating the dried meat at (43%), (42%), (3%), (2%), (2%), (1%), and (7%), respectively. High incidences were recorded for Aspergillus flavus, Aspergillus niger, and Aspergillus fumigatus in most of the screened samples. Aspergillus flavus accounted for (24.7%) of all the Aspergillus species isolated with the presence of the gene needed for aflatoxin production. The occurrences of these filamentous fungal species pose a cause for concern, as most of these fungal species are known producers of certain toxic substances. Maximum likelihood phylogenetic analysis showed a high similarity index score, which indicated a good relationship between isolated Aspergillus Species and the closely related strains from GenBank, isolated from different sources and countries. The implication of this study is that consumer health may be at risk through exposure to contaminated dried meat. Full article

Investigating the quality of bee products obtained across different geographical regions and analyzing their antimicrobial activity is of significant interest to various scientific disciplines. This study focuses on comparing the antimicrobial activity of honey and propolis samples from different areas of Alba County, Romania. The quality parameters of five samples of two types of bee products (honey and propolis) were assessed. Then, the samples were tested to comparatively determine their antimicrobial properties against 12 species of bacteria (Escherichia coli, Salmonella typhimurium, Salmonella enteritidis, Salmonella anatum, Salmonella choleraesuis, Pseudomonas aeruginosa, Pseudomonas fluorescens, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis, and Listeria monocytogenes) and 7 fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, Rhizopus stolonifer, Fusarium oxysporum, and Alternaria alternata). Of the bacterial strains, the most sensitive to the action of honey samples were the two strains of Staphylococcus followed by P. fluorescens. The two strains of Pseudomonas and L. monocytogenes were the most sensitive to the activity of propolis. Of the fungal strains, F. oxysporum was the most sensitive to the actions of both honey and propolis, followed by P. chrysogenum in the case of honey samples and the two Aspergillus strains in the case of propolis. These findings indicate that bee products are rich sources of bioactive compounds exhibiting strong antimicrobial properties and significant potential for the development of new phytopharmaceutical products. Full article

Rice-flavor baijiu is a distilled Chinese spirit prepared from Xiaoqu culture. However, its dull taste may be a market limitation. In order to enhance the flavor profile of rice-flavor baijiu, two ester-producing yeast strains (Saccharomyces cerevisiae and Cyberlindnera fabianii) were inoculated for fermentation. At the end of the fermentation, the total alcohol and ester contents had also increased by 43.3% and 29.8%, respectively, and the number of ester species had increased by eight. Additionally, eleven flavor substances had significant contributions in the inoculated fermentation process, including several different esters and alcohols. A macrogenomic analysis revealed that the majority of the gene abundances associated with the alcohol, acid, and ester pathways were elevated by the third day of inoculated fermentation, and greater abundances of Saccharomyces cerevisiae, Cyberlindnera fabianii, Lichtheimia ramosa, Rhizopus delemar, and Rhizopus oryzaefive, annotated with these genes, were observed from either the pre-fermentation stage or post-fermentation stage. The results demonstrate that two added strains are associated with an increase in the content of the flavor substances. These findings may prove beneficial in enhancing the quality of rice-flavor baijiu through using inoculated fermentation with ester-producing yeast. Full article

The fruit processing industry is responsible for disposing of huge amounts of byproducts, especially fruit peels (FPs), which are often discarded in landfills. Using FPs in biotechnological processes contributes to a circular economy, reducing the environmental burden of FPs and increasing the revenue of the fruit processing industry. This study was focused on upgrading the nutritional value of orange (OPs) and banana (BPs) peels by solid-state fermentation (SSF) with filamentous fungi. SSF factors (moisture, fermentation time, inoculum size, ammonium sulfate (AS), and corn steep liquor (CSL)) and fungi species (Aspergillus ibericus and Rhizopus oryzae) were studied by a variable screening Plackett–Burman design. Both fungi grew on untreated FPs, increasing their protein content and antioxidant activity. Moisture, AS, and CSL were further studied by a Box–Behnken design with A. ibericus. Fermented OPs at 70% moisture and 0.005 g/g AS increased their protein content by 200%, whereas BPs at 70% moisture and 0.005 g/g CSL increased by 123%. Fermented peels were enriched in protein, fiber, and minerals, with a low content of carbohydrates and soluble sugars. Fermented OPs and BPs showed higher antioxidant activity than unfermented peels. The SSF of these FPs is an innovative approach that contributes to obtaining rich nutrient-fermented peels for food. Full article

Essential oils (EOs) are natural products widely used in sustainable agrochemistry, not only because they are biodegradable and safe but also because they are regarded as alternatives to chemical fungicides against fungal species that attack crops. Allelopathy, another field of study, falls within the most recent and sustainable strategies applied to weed suppression to replace synthetic herbicides. Therefore, this study reports the chemical composition and allelopathic and antifungal effects of the EOs extracted from Calyptranthes concinna dried leaves (Cc-EO) and its pure major constituent elemicin. Their antifungal activities were evaluated by the disk diffusion method (DDM) at doses between 0.05 mg/mL and 0.4 mg/mL of Cc-EO and elemicin. The allelopathic effect was evaluated by studying the inhibition of germination and the growth of Lactuca sativa seeds. The chemical composition of Cc-EO was determined by GC-MS and GC-FID analyses. The major constituents of Cc-EO were elemicin (60.5%), α-cadinol (9.0%) and caryophyllene oxide (8.3%). Cc-EO and elemicin were assayed in vitro against 17 fungi of agronomic interest (Aspergillus niger, A. flavus, A. nomius, Penicillium digitatum, P. expansum, Sclerotinia sclerotiorum, S. rolfsii, S. minor, Fusarium graminearum, Myrothecium verrucaria, Corynespora cassiicola, Erwinia psidii, Colletotrichum musae, Alternaria carthami, Rhizoctonia solani, Rhizopus stolonifer and Macrophomina phaseolina). The concentration of Cc-EO (0.4 mg/mL) inhibited 100% of the mycelium growth of seven strains, equal to the fungicide fluazinam, which was used as a positive control. Elemicin showed antifungal activity against all fungi at all concentrations under investigation (above 50%). A strong allelopathic effect was recorded for Cc-EO and elemicin at the dose of 0.28 mg/mL, with the almost total inhibition of germination. This study revealed, for the first time, the strong and remarkable fungicidal and allelopathic effects of Cc-EO and elemicin, an important finding for the agrochemical field. Full article

Wound-invasive fungal diseases (WIFDs), especially mucormycosis, have emerged as life-threatening infections during recent military combat operations. Many combat-relevant fungal pathogens are refractory to current antifungal therapy. Therefore, animal models of WIFDs are urgently needed to investigate new therapeutic solutions. Our study establishes combat-relevant murine models of wound mucormycosis using Rhizopus arrhizus and Lichtheimia corymbifera, two Mucorales species that cause wound mucormycosis worldwide. These models recapitulate the characteristics of combat-related wounds from explosions, including blast overpressure exposure, full-thickness skin injury, fascial damage, and muscle crush. The independent inoculation of both pathogens caused sustained infections and enlarged wounds. Histopathological analysis confirmed the presence of necrosis and fungal hyphae in the wound bed and adjacent muscle tissue. Semi-quantification of fungal burden by colony-forming units corroborated the infection. Treatment with liposomal amphotericin B, 30 mg/kg, effectively controlled R. arrhizus growth and significantly reduced residual fungal burden in infected wounds (p < 0.001). This study establishes the first combat-relevant murine model of wound mucormycosis, paving the way for developing and evaluating novel antifungal therapies against combat-associated WIFDs. Full article

The degradation of the complex structure of lignocellulosic biomass is important for its further biorefinery to value-added bioproducts. The use of effective fungal species for the optimised degradation of biomass can promote the effectiveness of the biorefinery of such raw material. In this study, the optimisation of processing parameters (temperature, time, and s/w ratio) for cellulase activity and reducing sugar (RS) production through the hydrolysis of sugar beet pulp (SBP) by edible filamentous fungi of Aspergillus, Fusarium, Botrytis, Penicillium, Rhizopus, and Verticillium spp. was performed. The production of RS was analysed at various solid/water (s/w) ratios (1:10–1:20), different incubation temperatures (20–35 °C), and processing times (60–168 h). The Aspergillus niger CCF 3264 and Penicillium oxalicum CCF 3438 strains showed the most effective carboxymethyl cellulose (CMC) degrading activity and also sugar recovery (15.9–44.8%) from SBP biomass in the one-factor experiments. Mathematical data evaluation indicated that the highest RS concentration (39.15 g/100 g d.w.) and cellulolytic activity (6.67 U/g d.w.) could be achieved using A. niger CCF 3264 for the degradation of SBP at 26 °C temperature with 136 h of processing time and a 1:15 solid/water ratio. This study demonstrates the potential of fungal degradation to be used for SBP biorefining. Full article