Search Results (92)

Bamboo is a renewable and fast-growing biomass resource with limited utilization and service life owing to its susceptibility to mold. Conventional nano-modification methods, particularly two-step approaches, are limited by weak interfacial bonding between nanoparticles and the bamboo substrate, complex processing, and an inability to simultaneously enhance antimildew performance and dimensional stability. To address these limitations, we developed a one-step hydrothermal method involving the use of tannic acid (TA) for in situ fabrication of ZnO/TA/Ag composite particles on bamboo surfaces. Process parameters were optimized to 100 °C, 10 h, and a zinc acetate-to-tannic acid molar ratio of 20:1. The modified bamboo was characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and thermogravimetric analysis. We demonstrated that ZnO/TA/Ag composite particles were successfully loaded onto the bamboo surface, thus improving the all-around performance of the bamboo simultaneously. Antimildew activity against Aspergillus niger and Penicillium citrinum increased from grade 4 in untreated bamboo to grades 1 and 0, respectively; water absorption decreased by 52.85%, and anti-swelling efficiency reached 30.41%, indicating improved mold resistance and dimensional stability. Thus, our technique could serve as a green and efficient one-step in situ modification strategy for high-performance functionalization of bamboo, making it suitable for applications in humid outdoor and indoor environments. Full article

Marine endophytic fungi inhabit the internal tissues of seaweed, seagrass, and mangroves without causing harm. These fungi are known to produce extracellular enzymes, including proteases and cellulases, which play crucial roles in various biological processes and have potential applications in diverse industrial sectors. This study aimed to screen the enzymatic potential of marine endophytic fungi, identify selected isolates, and characterize their enzyme activities. A total of 20 fungal isolates were obtained, comprising 16 isolates from seaweed, three from seagrass, and one from mangrove leaves, collected from the coastal areas of the Seribu Islands (Jakarta), Sukabumi (West Java), Nusa Dua (Bali), and the Buton Islands (Southeast Sulawesi). Screening results showed that 50% of the isolates exhibited proteolytic activity on skim milk agar, while 40% demonstrated cellulolytic activity on carboxymethylcellulose (CMC) agar. Two isolates with the highest clear zone indices for protease and cellulase activity were identified as Penicillium citrinum and Fomitopsis sp., with distinct morphological characteristics including velvety colonies and filamentous hyphal structures. The specific activities of the protease and cellulase were 5475.42 ± 2724.25 U/mg protein and 620.77 ± 607.71 U/mg protein, respectively, indicating high catalytic potential. Full article

To reveal the mechanism underlying the effects of dominant spoilage fungi on wheat quality during storage and provide a theoretical basis for targeted microbial control in wheat storage, this study characterized the structural features of fungal communities on the surface of stored wheat and at different depths of the grain bulk via high-throughput sequencing. Additionally, screening was performed for stably existing dominant spoilage fungi in a wheat storage environment. Subsequently, four isolated dominant spoilage fungal strains, Fusarium lateritium, Aspergillus niger, Penicillium citrinum and Talaromyces islandicus, were back-inoculated onto wheat kernels sterilized by ⁶⁰Co gamma irradiation. Simulated storage trials were conducted at 28 °C and 80% relative humidity to investigate their impacts on wheat quality. The results show that F. lateritium and A. niger exhibited faster growth rates and were able to colonize the entire surface of wheat kernels within 8 days. After infection by these two fungi, wheat superoxide dismutase (SOD) activity decreased by 33.83 U/g and 21.90 U/g, peroxidase (POD) activity decreased by 1408 U/(g·min) and 745 U/(g·min), and electrical conductivity (EC) increased by 11.17 μS/(cm·g) and 7.74 μS/(cm·g), respectively. After 10 days of storage, A. niger significantly reduced the water absorption of wheat gluten to 175.91% and elevated the fatty acid value to 74.20 mg/100g, rendering the wheat unsuitable for storage. P. citrinum exerted the most significant effect on the solvent retention capacity (SRC) of wheat flour in water, sucrose, sodium carbonate, and lactic acid solutions. This study clarified the screening criteria for dominant spoilage fungi in stored wheat, as well as the threshold values and differential characteristics of the impacts of different dominant spoilage fungi on wheat quality, providing critical theoretical support for targeted microbial control during wheat storage. Full article

Three novel alkaloids, penicitrioids A–C (1–3), and two known compounds (4–5) were isolated from the ethyl acetate (EtOAc) extract of the solid fermentation of Penicillium citrinum VDL118, an endophytic fungus harbored in the leaves of Vaccinium dunalianum Wight (Ericaceae), a perennial evergreen shrub native to the southwestern regions of China, Myanmar, and Vietnam. Compounds 1 and 2 are novel pyridine alkaloids characterized by an unprecedented dihydrofuro[3,4-c]pyridine core, while 3 features a distinct pyrrolo[3,4-c]pyridine framework. Their structures were unambiguously established by comprehensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. In vitro antifungal assays revealed that compounds 1–5 exhibited moderate to potent inhibitory effects against five tested phytopathogenic fungi, with minimum inhibitory concentrations (MICs) ranging from 3.1 to 100 μg/mL. Notably, four of them (1–4) displayed broad-spectrum and potent activity against Gloeophyllum trabeum, Coriolus versicolor, Fusarium solani, and Botrytis cinerea, with MIC values as low as 3.1–12.5 μg/mL. Furthermore, a plausible biosynthetic pathway for compounds 1–3 was proposed. Full article

China has the largest strawberry cultivation area worldwide and produces substantial quantities of the fruit. However, postharvest diseases of strawberries occur frequently, limiting their safe storage. In November 2025, a localized occurrence of postharvest fruit rot affecting strawberry (cv. Hongyan) was observed in Tai’an, China. A pathogenic fungus, designated CM-RB5, was isolated from diseased fruits and identified as Penicillium citrinum based on morphological characteristics and molecular analyses. This is the first report of P. citrinum causing postharvest fruit rot in strawberry. The genome of the pathogenic fungal strain CM-RB5 was sequenced using the Illumina MiSeq II and PacBio RS III platforms. Genome assembly analysis revealed the total sequence length of P. citrinum CM-RB5 to be 32,053,718 bp, with a GC content of 46.41%. Additionally, P. citrinum CM-RB5 was found to produce ochratoxin and citrinin. These findings provide insights that may facilitate the development of effective control strategies for postharvest fruit rot in strawberry, thereby ensuring the consumption of safe, high-quality fruit and strawberry-derived products. Full article

Species of Penicillium are among the most important fungal pathogens responsible for postharvest diseases of agricultural crops worldwide. This review provides an overview of five economically important Penicillium spp., namely P. expansum, P. digitatum, P. italicum, P. citrinum, and P. oxalicum. Emphasis is placed on P. expansum, P. digitatum, and P. italicum which are the main causal agents of blue mold and green mold rots in pome fruits and citrus, commodities that dominate global fresh produce trade and long-term storage. While studies on plant-pathogenic Penicillium are mainly focused on these hosts, this review highlights reports of infections in other crops across diverse geographic regions, highlighting the broader host range of these species. The main aspects highlighted include host specificity and diversity, production of mycotoxins and other secondary metabolites, current management and control strategies, and the potential influence of climate change on disease incidence and severity. Understanding the biology and epidemiology of plant-pathogenic Penicillium species is essential, as several species are both pathogens and producers of mycotoxins, leading to quality deterioration and nutrient depletion resulting in economic losses. Full article

This study provides a combined profile of fungal isolates from fresh and dried chili peppers in markets in Guangzhou. Multilocus sequence analysis revealed a wide variety of species, seven of which were reported for the first time from chili pepper (F. annulatum, F. compactum, F. pernambucanum, F. ramsdenii, and F. tardichlamydosporum, P. citrinum and P. steckii). In this research work, quantitative determination using targeted LC–MS/MS of dried chili peppers showed a significantly higher frequency of contamination and higher toxin concentrations than fresh samples. The predominant mycotoxins in dried peppers were DON and FB₁, which were present in all the samples at mean levels of 0.56 µg/g and 0.067 µg/g, respectively. AFB₁ and OTA were present in all dried samples but were detected only occasionally in fresh peppers. ZEN and CIT were detected at lower concentrations, but more prevalent among dried products (63.6% and 81.8% of all samples, respectively). The aflatoxin B₁ (AFB₁) level of 180 µg/kg in dried chili samples was 36 times above the EU maximum limit (5 µg/kg), and the OTA level reached 54 µg/kg, exceeding the EU limit by a factor of 2.7 (20 µg/kg). Statistical analysis also showed that all six mycotoxins were statistically higher in dried pepper than in fresh pepper. In vitro evaluation demonstrated that certain Fusarium isolates synthesized FB₁. At the same time, Penicillium species, including P. citrinum and P. steckii, consistently produced citrinin, confirming the strong influence of growth substrate on toxin biosynthesis. The frequent occurrence and elevated levels of regulated mycotoxins highlight significant public health concerns and underscore the need for improved postharvest handling and drying practices. These findings provide critical baseline data linking fungal diversity with toxin production dynamics, developing essential guidance for targeted mitigation strategies. Full article

This study evaluated the potential of sawdust as an inducer of carbon for the production of lignocellulolytic (cellulase and xylanase) enzymes by filamentous fungi for biofuel applications. Fourteen soil samples were collected from a phosphate mine in Phalaborwa, South Africa. Filamentous fungi were isolated from these samples using cellulose and xylose media. These isolateswere tested qualitatively and quantitatively for endocellulase and xylanases. Four isolates were found to have promising xylanase activity and these were identified as Amesia atrobrunnea, Penicillium citrinum, Rhizopus azygosporus and Aspergillus quadrilineatus using ITS1/2 sequencing. A time-course assay for xylanase activity revealed that R. azygosporus and A. quadrilineatus exhibited the highest activity. The crude enzymes were extracted from these strains and used for the enzymatic saccharification of the untreated sawdust. The total reducing sugars were estimated using the DNS method. The results for the enzymatic saccharification showed that a high total reducing sugar concentration of 2.35 g/L was released by 20 U/g of crude xylanases from A. quadrilineatus after 60 h of hydrolysis, while the synergistic hydrolysis of sawdust with the commercial cellulase, Celic CTec2, and the crude enzyme of 6 U/g from A. quadrilineatus showed the maximum concentration of total reducing sugars of 1.41 g/L after 72 h. Sawdust proved to be an effective inducer of xylanase production, although it was less effective for cellulase. This study reports that the commercial cellulase was outperformed by the crude enzymes during hydrolysis, highlighting the possibility that commercial enzymes may be replaced by microbial enzymes, thus lowering the environmental hazards of chemical formulations. Sugar yields could potentially be improved through biomass pretreatment, enzyme purification and strain improvement. Full article

The Brazil nut production chain, which is reliant on Amazonian environmental conditions, is significantly affected by climate change, particularly extreme droughts, which decrease production and compromise sanitary quality. This study evaluated the influence of severe drought on aflatoxin concentrations and sequence toxigenic fungi in Brazil nuts harvested during the 2023 off-season. Aflatoxins were quantified using high-performance liquid chromatography, while fungal sequencing involved DNA extraction, PCR, and sequencing analysis. Findings indicated that all Brazil nut samples collected during extreme drought contained detectable aflatoxins, with 10% exceeding the legal threshold of 10 µg/kg. Phylogenetic analysis identified four isolates as Penicillium citrinum. Additional morphological and sequencing analyses identified Aspergillus species from the Circumdati and Flavi sections, although one isolate could not be taxonomically classified. These results demonstrate the aflatoxin production by fungi in Brazil nuts in an unprecedented way under drought conditions. Furthermore, the diversity of fungal species during drought underscores the risk of contamination, emphasizing the necessity for monitoring future harvests to improve management and ensure product safety. Full article

The ‘Akizuki’ pear has become increasingly popular in China in recent years. However, the ‘Akizuki’ pear often suffers from severe rot diseases during the postharvest storage period. Those during storage have not been thoroughly elucidated In this study, fungal pathogens causing postharvest decay of ‘Akizuki’ pear were identified through multi-gene phylogenetic analysis, followed by assessment of the antifungal efficacy of chlorine dioxide (ClO₂) at varying concentrations. A total of 18 strains were isolated and identified as pathogens by Koch postulates. The isolated pathogens were taxonomically identified by combining morphological characterization of hyphae/spores with multi-gene phylogeny (ITS, β-tub, tef1). The results revealed that isolates A1-A11 were identified as Alternaria alternata, D1-D3 as Diaporthe eres, P1 as Penicillium citrinum, and P2-P4 as Penicillium expansum. The strain with the strongest pathogenicity in each genus was selected as the representative strain for subsequent control experiments. ClO₂ significantly inhibited the development of the D. eres, A. alternata, and P. expansum by suppressing mycelial growth and disrupting cell membrane structure of pathogens, in which the EC50 values were 35.56 mg/L, 24.71 mg/L, and 41.98 mg/L, respectively, showing comparable antifungal activity to conventional fungicides. This has clarified the occurrence and control of postharvest decay diseases of ‘Akizuki’ pear fruit and provided more options for the practical applications in postharvest disease control of pear fruits. Full article

The continuous increase in microbial resistance to therapeutic agents has become one of the greatest challenges to global health. In this context, the present study investigated the bioactivity of 25 chroman-4-one and homoisoflavonoid derivatives—17 of which are novel—against pathogenic microorganisms, including Staphylococcus epidermidis, Pseudomonas aeruginosa, Salmonella enteritidis, Candida albicans, C. tropicalis, Nakaseomyces glabratus (formerly C. glabrata), Aspergillus flavus, and Penicillium citrinum. Antimicrobial assay was performed using the microdilution technique in 96-well microplates to determine the minimum inhibitory concentration (MIC). Thirteen compounds exhibited antimicrobial activity, with compounds 1, 2, and 21 demonstrating greater potency than the positive control, especially against Candida species. Molecular modeling suggested distinct mechanisms of action in Candida albicans: 1 potentially inhibits cysteine synthase, while 2 and 21 possibly target HOG1 kinase and FBA1, key proteins in fungal virulence and survival. Our findings indicated that the addition of alkyl or aryl carbon chains at the hydroxyl group at position 7 reduces antimicrobial activity, whereas the presence of methoxy substituents at the meta position of ring B in homoisoflavonoids enhances bioactivity. These findings highlight key structural features of these compound classes, which may aid in the development of new bioactive agents against pathogenic microorganisms. 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

Several species of Fusarium are reported to infect inflorescences of high-THC-containing cannabis (Cannabis sativa L.) plants grown in greenhouses in Canada. These include F. graminearum, F. sporotrichiodes, F. proliferatum, and, to a lesser extent, F. oxysporum and F. solani. The greatest concern surrounding the infection of cannabis by these Fusarium species, which cause symptoms of bud rot, is the potential for the accumulation of mycotoxins that may go undetected. In the present study, both naturally infected and artificially infected inflorescence tissues were tested for the presence of fungal-derived toxins using HPLC-MS/MS analysis. Naturally infected cannabis tissues were confirmed to be infected by both F. avenaceum and F. graminearum using PCR. Pure cultures of these two species and F. sporotrichiodes were inoculated onto detached inflorescences of two cannabis genotypes, and after 7 days, they were dried and assayed for mycotoxin presence. In these assays, all Fusarium species grew prolifically over the tissue surface. Tissues infected by F. graminearum contained 3-acetyl DON, DON, and zearalenone in the ranges of 0.13–0.40, 1.18–1.91, and 31.8 to 56.2 μg/g, respectively, depending on the cannabis genotype. In F. sporotrichiodes-infected samples, HT2 and T2 mycotoxins were present at 13.9 and 10.9 μg/g in one genotype and were lower in the other. In F. avenaceum-inoculated tissues, the mycotoxins enniatin A, enniatin A1, enniatin B, and enniatin B1 were produced at varying concentrations, depending on the isolate and cannabis genotype. Unexpectedly, these tissues also contained detectable levels of 3-acetyl DON, DON, and zearalenone, which was attributed to apre-existing natural infection by F. graminearum that was confirmed by RT-qPCR. Beauvericin was detected in tissues infected by F. avenaceum and F. sporotrichiodes, but not by F. graminearum. Naturally infected, dried inflorescences from which F. avenaceum was recovered contained beauvericin, enniatin A1, enniatin B, and enniatin B1 as expected. Uninoculated cannabis inflorescences were free of mycotoxins except for culmorin at 0.348 μg/g, reflecting pre-existing infection by F. graminearum. The mycotoxin levels were markedly different between the two cannabis genotypes, despite comparable mycelial colonization. Tall fescue plants growing in the vicinity of the greenhouse were shown to harbor F. avenaceum and F. graminearum, suggesting a likely external source of inoculum. Isolates of both species from tall fescue produced mycotoxins when inoculated onto cannabis inflorescences. These findings demonstrate that infection by F. graminearum and F. avenaceum, either from artificial inoculation or natural inoculum originating from tall fescue plants, can lead to mycotoxin accumulation in cannabis inflorescences. However, extensive mycelial colonization following prolonged incubation of infected tissues under high humidity conditions is required. Inoculations with Penicillium citrinum and Aspergillus ochraceus under these conditions produced no detectable mycotoxins. The mycotoxins alternariol and tentoxin were detected in several inflorescence samples, likely as a result of natural infection by Alternaria spp. Fusarium avenaceum is reported to infect cannabis inflorescences for the first time and produces mycotoxins in diseased tissues. Full article

Malaria remains a public health issue across the world. Different methods have been analyzed to achieve this disease’s elimination, such as the vector control of Anopheles spp. Control strategies include the use of different classes of insecticides, although the accelerated evolution of vectors resistant to them makes the development of alternative control methods necessary. Therefore, entomopathogenic fungi have been considered to be promising biopesticides, given that they are safe for human beings and the environment. This study aimed to evaluate the entomopathogenic activity of fungi collected in the Amazon Rainforest against adult female Anopheles aquasalis mosquitoes. Females were exposed to four different species of fungi and observed daily to evaluate their survival rate. Also, fungi species’ behavior was analyzed through scanning electron microscopy (SEM). Those exposed to Trichoderma harzianum and Penicillium citrinum had their survival rate reduced. SEM confirmed the development of fungi on the mosquitoes after 48 h. The findings suggest that the entomopathogenic potential of the fungi used in this study should be considered, given the reduction in the survival rate of Anopheles aquasalis mosquitoes. Full article

The application of chemical additives in poultry litter management aims to control the microbial population and reduce harmful gases. We conducted in vitro analyses to determine and compare the minimum inhibitory concentration (MIC) of commercial chemical additives of calcium oxide, aluminum sulphate, and copper sulphate on bacteria such as Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa; yeast (Candida albicans); and fungi (Aspergillus flavus and Penicillium citrinum). The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were also evaluated. Chemical additive solutions were prepared at a concentration of 0.1 g/mL and diluted up to 0.00078 g/mL, corresponding to concentrations from 10 kg/m² to 0.07 kg/m² when the additives were applied to the litter. In general, aluminum sulphate inhibited the growth of bacterial and fungal strains at a concentration of 0.62 kg/m² (6.25%). On the other hand, additives based on copper sulphate and calcium oxide showed an inhibitory effect on bacterial and fungal strains at dosages above 2.5 kg/m² and 5 kg/m², respectively. Research into commercially available poultry products is rare but important for determining the correct dosage of chemical additives to control the microbial and fungal population of poultry litter. The use of a correct dosage can prevent microbial resistance to chemical additives. This study continues to analyze the use of additives on commercial farms. Full article