Search

BACKGROUND The high cost of controlled-release urea (CRU) has prompted this study to explore whether the amount of CRU can be reduced by adding biostimulants while maintaining or increasing rice yield. A 2 year field experiment was conducted with CRU at three levels (60%, 80%, and 100% of the recommended nitrogen (N) fertilizer) and a novel biostimulant Paecilomyces variotii extract (ZNC), to investigate their synergistic effects on yield, nitrogen use efficiency (NUE), and net profitability of rice. RESULTS Controlled-release urea achieved a significantly higher gain yield and NUE than conventional urea with the same N level, which could be attributed to its N supply. Even if the N level of CRU was reduced by 40%, both rice yield and net profit were still significantly higher than for the full amount of urea. Paecilomyces variotii extract sprayed on the surface of CRU at a dose of only 87.5 mL ha-1 exhibited ultra-high effectiveness by increasing the panicles, the N accumulation, and the rice yield. Controlled-release urea enriched by ZNC achieved significantly higher gain yield than CRU alone, increasing the yield by 9.2% and 8.7%, respectively, in 2 years under the full recommended N rate. The combination of 80% CRU and ZNC showed no significant difference in rice yield from treatment with 100% CRU, indicating that the rate of CRU could be reduced by ZNC. The application of ZNC further increased NUE, N partial factor productivity, and net profit. CONCLUSION The CRU and ZNC combination provided a feasible approach for reducing N input while maintaining rice yield and agricultural sustainability. © 2021 Society of Chemical Industry.

The mycotoxin patulin is primarily produced as a secondary metabolite by numerous fungal species and predominantly by Aspergillus, Byssochlamys, and Penicillium species. It is generally associated with fungal infected food materials. Penicillium expansum is considered the only fungal species liable for patulin contamination in pome fruits, especially in apples and apple-based products. This toxin in food poses serious health concerns and economic threat, which has aroused the need to adopt effective detection and mitigation strategies. Understanding its origin sources and biosynthetic mechanism stands essential for efficiently designing a management strategy against this fungal contamination. This review aims to present an updated outline of the sources of patulin occurrence in different foods and their biosynthetic mechanisms. It further provides information regarding the detrimental effects of patulin on human and agriculture as well as its effective detection, management, and control strategies.

Melanin-containing fungi (black molds) have the capacity to thrive under extreme environmental conditions such as the elevated radiation levels inside the former Chernobyl reactors. These fungi have been hypothesized to grow toward and use gamma radiation as an energy source, but the literature does not clearly address which energies of the electromagnetic spectrum, if any, positively affect fungal growth. The goal of this work was to characterize the response of non-melanized and melanized fungi to two distinct electromagnetic wavelengths, i.e., ultraviolet (UV) and gamma ray, keeping absorption and other potentially confounding variables constant. Exposure to UV or gamma radiation induced significant changes in fungi pigmentation, but not growth rate of Cladosporium cladosporioides and Paecilomyces variotii. Specifically, increased pigmentation of both fungi was observed in samples exposed to UV, while decreased pigmentation was observed for gamma-irradiated samples. These results provide new insights into the role of electromagnetic energies on growth of fungi and provide an impetus to examine additional energies and types of radiation to develop a fundamental understanding of this phenomenon.

Fruit syrups or concentrates are sweeteners that are used in food and beverage industry as well as in the pharmaceutical industry. These fruit syrups or juice concentrates are naturally acidic products that are subjected to pasteurization to eliminate the vegetative cells of bacteria, fungi and their less heat resistant spores. There is a chance for heat resistant moulds and Alicyclobacillus spp. to grow in the product after the pasteurization due to the production of heat resistant structures such as ascospores or similar structures and bacterial spores. Byssochlamys, Talaromyces and Neosartorya have been identified frequently as heat resistant moulds in heat processed fruit products. Heat resistant moulds can cause an economical damage to the products by breaking down the texture, producing off flavors, phase separation and causing health hazards due to the ability of mycotoxins formation by some species. In order to detect heat resistant moulds it is necessary to give a selective heat treatment by the laboratory pasteurization to eliminate vegetative cells of bacteria, fungi and less heat resistant fungal spores while stimulation the activation of heat resistant spores formed by heat resistant moulds. Due to the low occurrence of the spores relatively large samples are analyzed. Most of the methods suggest a long incubation period of 30 days to mature the colonies that is too long for quality control measures in food and beverage industry. Impedance monitoring has been suggested as a rapid detection method for the detection of common heat resistant moulds such as Byssochlamys.

Four new carotane sesquiterpenoids, byssocarotins A-D (

It is trite to say that dried foods must be kept dry, heat processed foods must be heated enough to inactivate all relevant spores, and preservative concentrations must be high enough to inhibit all fungi. The science of preserving foods, like so many other disciplines, requires compromise. Really dry foods, i.e. of a safe aw, may be impossible to obtain for climatic or economic reasons, or be unacceptable to the consumer; a sufficient heat process may destroy desirable flavours; and permitted preservative levels are set by law. Some fungi, by virtue of specific attributes, simply cannot be processed out of certain types of foods. Of particular importance are Xeromyces bisporus and Zygosaccharomyces rouxii — extreme xerophiles which grow in concentrated foods; Byssochlamys spp. and Neosartorya fischeri with ascospores of very high heat resistance which can survive heat processing and grow in heat processed acid foods; and Zygosaccharomyces bailii, a preservative resistant yeast. Making foods safe from these fungi requires that they be absent from raw materials or destroyed by pasteurisation, and then excluded from the processing and packing lines.

Polymicrobial co-fermentation is among the distinct character of high-temperature Daqu. However, fungal communities in the three types of high-temperature Daqu, namely, white high-temperature Daqu, black high-temperature Daqu, and yellow high-temperature Daqu, are yet to be characterized. In this study, the fungal diversity, taste, and aroma profiles in the three types of high-temperature Daqu were investigated by Illumina MiSeq high-throughput sequencing, electronic tongue, and electronic nose, respectively. Ascomycota and Basidiomycota were detected as the absolute dominant fungal phylum in all types of high-temperature Daqu samples, whereas Thermomyces, Thermoascus, Aspergillus, Rasamsonia, Byssochlamys, and Trichomonascus were identified as the dominant fungal genera. The fungal communities of the three types of high-temperature Daqu differed significantly (p < 0.05), and Thermomyces, Thermoascus, and Monascus could serve as the biomarkers in white high-temperature Daqu, black high-temperature Daqu, and yellow high-temperature Daqu, respectively. The three types of high-temperature Daqu had an extremely significant difference (p < 0.01) in flavor: white high-temperature Daqu was characterized by sourness, bitterness, astringency, richness, methane, alcohols, ketones, nitrogen oxides, and sulfur organic compounds; black high-temperature Daqu was characterized by aftertaste-A, aftertaste-B, methane-aliph, hydrogen, and aromatic compounds; and yellow high-temperature Daqu was characterized by saltiness, umami, methane, alcohols, ketones, nitrogen oxides, and sulfur organic compounds. The fungal communities in the three types of high-temperature Daqu were significantly correlated with taste but not with aroma, and the aroma of high-temperature Daqu was mainly influenced by the dominant fungal genera including Trichomonascus, Aspergillus, Thermoascus, and Thermomyces. The result of the present study enriched and refined our knowledge of high-temperature Daqu, which had positive implications for the development of traditional brewing technique.

Fungi that degrade B20 biodiesel in storage tanks have also been linked to microbiologically influenced corrosion (MIC). A member of the filamentous fungal genus Byssochlamys, and a yeast from the genus Wickerhamomyces were isolated from heavily contaminated B20 storage tanks from multiple Air Force bases. Although these taxa were linked to microbiologically influenced corrosion in situ, precise measurement of their corrosion rates and pitting severity on carbon steel was not available. In the experiments described here, we directly link fungal growth on B20 biodiesel to higher corrosion rates and pitting corrosion of carbon steel under controlled conditions. When these fungi were growing solely on B20 biodiesel for carbon and energy, consumption of FAME and n-alkanes was observed. The corrosion rates for both fungi were highest at the interface between the B20 biodiesel and the aqueous medium, where they acidified the medium and produced deeper pits than abiotic controls. Byssochlamys produced the most corrosion of carbon steel and produced the greatest pitting damage. This study characterizes and quantifies the corrosion of carbon steel by fungi that are common in fouled B20 biodiesel through their metabolism of the fuel, providing valuable insight for assessing MIC associated with storage and dispensing B20 biodiesel.IMPORTANCEBiodiesel is widely used across the United States and worldwide, blended with ultralow sulfur diesel in various concentrations. In this study we were able to demonstrate that the filamentous fungi Byssochlamys AF004 and the yeast Wickerhamomyces SE3 were able to degrade fatty acid methyl esters and alkanes in biodiesel causing increases in acidity. Both fungi also accelerated the corrosion of carbon steel, especially at the interface of the fuel and water, where their biofilms were located. This research provides controlled, quantified measurements and the localization of microbiologically influenced corrosion caused by common fungal contaminants in biodiesel fuels.

Paecilomyces rot of apples is a postharvest disease caused by

Paecilomyces variotii xylanase was, produced in stirred tank bioreactor with yield of 760 U/mL and purified using 70% ammonium sulfate precipitation and ultra-filtration causing 3.29-fold purification with 34.47% activity recovery. The enzyme purity was analyzed on sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) confirming its monomeric nature as single band at 32 KDa. Zymography showed xylan hydrolysis activity at the same band. The purified enzyme had optimum activity at 60 °C and pH 5.0. The pH stability range was 5–9 and the temperature stability was up 70 °C. Fe2+and Fe3+ exhibited inhibition of xylanase enzyme while Cu2+, Ca2+, Mg2+ and Mn2+ stimulated its activity. Mercaptoethanol stimulated its activity; however, Na2-EDTA and SDS inhibited its activity. The purified xylanase could hydrolyze beechwood xylan but not carboxymethyl cellulose (CMC), avicel or soluble starch. Paecilomyces variotii xylanase Km and Vmax for beechwood were determined to be 3.33 mg/mL and 5555 U/mg, respectively. The produced xylanase enzyme applied on beech xylan resulted in different types of XOS. The antioxidant activity of xylo-oligosaccharides increased from 15.22 to 70.57% when the extract concentration was increased from 0.1 to 1.5 mg/mL. The enzyme characteristics and kinetic parameters indicated its high efficiency in the hydrolysis of xylan and its potential effectiveness in lignocellulosic hydrolysis and other industrial application. It also suggests the potential of xylanase enzyme for production of XOS from biomass which are useful in food and pharmaceutical industries.

Orientadores: Pilar Rodriguez de Massaguer, Amauri Rosenthal Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Resumo: A patulina é uma micotoxina produzida por fungos pertencentes aos gêneros Penicillium, Aspergillus e Byssochlamys. Penicillium expansum se destaca por ser potencial produtor de patulina nas maçãs, enquanto Byssochlamys nivea e B.fulva se destacam pela potencial produção desta micotoxina em sucos de maçãs pasteurizados. À patulina tem sido atribuídos diversos efeitos agudos e crônicos adversos à saúde humana. No presente estudo determinou-se quantitativamente o risco dos níveis de patulina no suco de maçã ultrapassar o limite de 50ppb estabelecido pela Organização Mundial de Saúde (OMS) e a probabilidade de produção da patulina por bolores termoresistentes sobreviventes à pasteurização do produto. Para isto, i) avaliou-se a ocorrência de bolores termoresistentes e patulina em amostras pertencentes à 5 diferentes lotes de suco de maçã provenientes de uma unidade produtora localizada no sudeste do Brasil; ii) avaliou-se a capacidade de produção da patulina por cepas de B.fulva (IOC 4518) e B.nivea (ATCC 24008 e FRR 4421) em suco de maçã armazenado à 21ºC e à 30ºC (consideradas temperaturas médias anuais das regiões tropicais e subtropicais do Brasil); iii) determinou-se a cepa Byssochlamys produtora de patulina mais termoresistente dentre as três estudadas, em suco de maçã; iv) determinou-se a resistência térmica através do método dos tubos TDT (thermal death tubes) da cepa mais termoresistente; v) Estabeleceu-se o efeito da pasteurização em sistema contínuo (UHT), simulando as condições industriais, sobre a cepa de Byssochlamys spp mais termoresistente produtora de patulina; vi) determinou-se a probabilidade de produção de patulina pela cepa mais termoresistente produtora de patulina em suco clarificado de maçã variando-se a temperatura de estocagem (21ºC e 30ºC), com carga remanescente pós-processo de 10º e 101 esporos / 100 mL e vii) determinou-se quantitativamente o risco da patulina em suco clarificado de maçã a partir de 15 cenários que relacionados a diferentes cargas de esporos sobreviventes e temperatura de estocagem do suco pós-pasteurização, utilizando-se a modelagem de Monte Carlo, feita através do software @RISK versão 4.5 for students com 1 simulação e 10000 iterações. Os resultados revelaram que a ocorrência de bolores termoresistentes nas amostras de suco de maçã é baixa (

Corn dry milling provides a mature model for lignocellulose biorefinery process. To copy this technical success, a crucial step is to transform lignocellulose into starch-like carbohydrates (SLC), similar to milled corn grain and in a similar fashion to corn dry milling. The transformation process should be zero wastewater generation and sufficient fermentable sugar conservation; the product should be in solid particle form, free of toxic residues, and high enzymatic hydrolysis yield and fermentability. Here we designed and verified a SLC transformation process by (i) biodegradable oxalic acid-catalyzed pretreatment, and (ii) simultaneous biodegradation of inhibitors and oxalic acid catalyst. The oxalic acid catalyst was effective on disrupting the lignocellulose structure and also biodegradable at low pH value. The biodetoxification fungus Paecilomyces variotii FN89 was capable of degrading the furan/phenolic aldehydes and oxalic acid simultaneously and ultimately, while the fermentable sugars were well preserved. The obtained SLC from wheat straw and corn stover were similar to dry milled corn meal in terms of morphological properties, fermentable sugar contents, enzymatic hydrolysis yield, elemental contents, and free of inhibitors and acid catalyst. The bioconversion of starch-like wheat straw and corn stover produced 78.5 and 75.3 g/L of ethanol (9.9% and 9.5%, v/v) with the yield of 0.47 and 0.45 g ethanol/g cellulose/xylose, respectively, compared with 78.7 g/L (10.0%, v/v) from corn meal and the yield of 0.48 g ethanol/g starch. Mass balances suggest that the ethanol yield, wastewater generation, and elemental recycling of the SLC from lignocellulose were essentially the same as those of corn meal.

Fungi produce secondary metabolites that are not directly involved in their growth, but often contribute to their adaptation to extreme environmental stimuli and enable their survival. Conidial pigment or melanin is one of the secondary metabolites produced naturally by a polyketide synthesis (PKS) gene cluster in several filamentous fungi and is known to protect these fungi from extreme radiation conditions. Several pigmented or melanized fungi have been shown to grow under extreme radiation conditions at the Chernobyl nuclear accident site. Some of these fungi, including Paecilomyces variotii, were observed to grow towards the source of radiation. Therefore, in this study, we wanted to identify if the pigment produced by P. variotii, contributes to providing protection against radiation condition. We first identified the PKS gene responsible for synthesis of pigment in P. variotii and confirmed its role in providing protection against UV irradiation through CRISPR-Cas9 mediated gene deletion. This is the first report that describes the use of CRISPR methodology to create gene deletions in P. variotii. Further, we showed that the pigment produced by this fungus, was not inhibited by DHN-melanin pathway inhibitors, indicating that the fungus does not produce melanin. We then identified the pigment synthesized by the PKS gene of P. variotii, as a naptho-pyrone Ywa1, by heterologously expressing the gene in Aspergillus nidulans. The results obtained will further aid in understanding the mechanistic basis of radiation resistance.

Background Several fungal taxa, including Aspergillus, Byssochlamys, and Penicillium species produce the mycotoxin patulin in contaminated food materials. Patulin is an unsaturated heterocyclic lactone that strongly reacts with thiol groups of macromolecules and causes serious health problems in humans and animals. Due to the high toxicity of patulin, many toxicological regulatory organizations around the world have set a maximum limit for patulin levels in foods. Thus, several research groups are involved in diverse studies on patulin, including the development of new technologies for its detection and effective neutralization and elucidation of its toxicological effects. Scope and approach Investigators are currently primarily focusing on the key role of patulin toxicity at the molecular level in various cell lines and animal models. The current review article discusses the effects of patulin on cells, organelles, tissues, organs, and the molecular regulation of macromolecules like proteins and nucleic acids. Key findings and conclusions Patulin primarily damages vital organs such as kidneys, liver, gastrointestinal tract, organs of the immune system, and endocrine glands. It also induces overproduction of intracellular reactive oxygen species, which perform a key function in mitochondrial and endoplasmic reticulum stress. Patulin induces DNA damage that leads to cell cycle arrest, consequently inhibiting the activity of cell survival proteins and promoting cell death by apoptosis. Patulin significantly affects the expression of several key proteins involved in cell junctions, membrane potential, protein synthesis, cell signaling, and gene expression.

Paecilomyces rot of apples is a postharvest disease caused by the thermotolerant fungus Paecilomyces niveus (Byssochlamys nivea). The etiology of disease and the activity of fungicides against P. niveus are not yet well understood. This study evaluated the ability of P. niveus to infect ‘Gala’ apples growing in a conventionally managed orchard. In addition, the sensitivity of P. niveus isolates to postharvest fungicides difenoconazole, fludioxonil, and pyrimethanil was characterized for isolates from both agricultural and nonagricultural environments. Apples were wounded and mock-inoculated or inoculated with P. niveus in early July. At the time of harvest, 8 weeks after wounding, the inoculated apples had significantly larger lesions than mock-inoculated apples (P < 0.005). The average diameter of lesions on wound-inoculated apples was 11.17 mm ± 6.82 SD, while the average diameter of mock-inoculated lesions was 3.34 mm ± 1.85 SD. Disease symptoms in the orchard were similar to postharvest symptoms of Paecilomyces rot. Symptoms included a brown, flattened, circular lesion with faint concentric rings. The necrosis of mesocarp was firm and roughly U-shaped. Baseline isolates of P. niveus, from nonagricultural environments, were used to determine the effective fungicide dose at which growth was inhibited by 50% (EC50). Furthermore, fungicide sensitivity of P. niveus isolates was examined using relative growth assays at the mean baseline EC50 values to compare baseline isolates with isolates obtained from commercial apple orchards where they were likely exposed to fungicides. Among the exposed isolates, reduced sensitivity to all fungicides was observed, but significant differences between baseline and exposed isolates were only observed with fludioxonil (P < 0.0001). This is the first report demonstrating that P. niveus can infect apples that are wound-inoculated in the orchard and that isolates from agricultural environments are less sensitive to common fungicides, especially fludioxonil. This finding may have implications for the control of this postharvest diseases. Whether natural infections of apples by P. niveus is initiated in the orchard or during postharvest has yet to be determined.

Wheat-originated microbes play an important role in shaping the quality of high-temperature Daqu which is commonly used as a starter for producing sauce-flavor Baijiu. However, the shifts of microbiota from raw material to fresh Daqu and then to mature Daqu remain unclear. Hence, in the present study, the inner and outer of fresh and mature Daqu were collected to explore the correlation between microbiota and metabolites as well as the source of the microbiota in Daqu. Results indicated that the activities of amylase and protease between the inner and outer of fresh Daqu varied significantly while both parts became similar after maturation. The predominant bacteria shifted from Saccharopolyspora (outer) and Staphylococcus (inner) to Kroppenstedtia (both outer and inner), while the predominant fungi shifted from Thermoascus (both outer and inner) to Byssochlamys (outer) and Fusarium (inner). A combining analysis of headspace solid-phase micro extraction-gas chromatography-mass spectrometry, headspace gas chromatography-ion mobility spectrometry, and nuclear magnetic resonance was employed to detect the metabolites. The network analysis was conducted to perform the relationships between microbes and metabolites. The results showed that the bacteria, especially Saccharopolyspora, Bacillus, and Acinetobacter, had a strong correlation with the productions of esters, amino acids and their derivatives, and sugars and their derivatives, while most fungi such as Thermoascus, were negatively correlated with the phenylalanine, trimethylamine n-oxide, and isovalerate. SourceTracker analysis indicated that wheat was the important source of the Daqu microbiota, especially, the microorganisms in the inner of Daqu might be the drivers of the microbial succession during maturation. This study provided a comprehensive exploration to understand the microbial sources and shifts in high-temperature Daqu during maturation.

The effect of ultrasound treatment (100 W, 30 kHz; 50 and 100% amplitudes) on inactivation of

Mycetoma is a progressively mutilating infectious disease of the subcutaneous tissue that affects the skin and deep structures, which is poorly responsive to chemotherapy. Here, we report a skin mycetoma caused by Paecilomyces variotii, an uncommon fungus of human infections, and the therapeutic approach that resulted in a complete cure of the patient.

Contamination by spores is often the cause of fungal food spoilage. Some distinct strains of the food spoilage fungus Paecilomyces variotii are able to produce airborne conidia that are more heat-resistant than similar species. These ellipsoid asexual spores can vary in size between strains, but also within strains. Here, we compared four measurement techniques to measure conidia size and distribution of five heat-sensitive and five heat-resistant P. variotii strains. Light microscopy (LM), Scanning Electron Microscopy (SEM) and Coulter Counter (CC) were used to measure and compare the spherical equivalent diameter, while CC and flow cytometry were used to study spore size distributions. The flow cytometry data was useful to study spore size distributions, but only relative spore sizes were obtained. There was no statistic difference between the method used of spore size measurement between LM, SEM and CC, but spore size was significantly different between strains with a 2.4-fold volume difference between the extremes. Various size distribution and shape parameters were correlated with conidial heat resistance. We found significant correlations in mean spore size, aspect ratio, roundness and skewness in relation to heat resistance, which suggests that these parameters are indicative for the conidial heat resistance of a P. variotii strain.

Patulin, one of the most common mycotoxins produced primarily by the Penicillium, Aspergillus and Byssochlamys species, is often associated with fruits and fruit-based products. Biodegradation by microbes is an effective method to remove or detoxify mycotoxins. In this study, a bacterial strain with patulin degradation capability was selectively isolated using oxindole, an analogue to patulin, as the sole carbon source, and identified as Pseudomonas poae JSU-Y1 by phylogenetic analysis on the basis of 16S rRNA sequence. This isolated bacterium could inhibit the growth of Penicillium expansum both on plate medium and apple fruit with inhibition ratio of 30.3% and 44.9%, respectively. Up to 87.7% of the initial patulin (2.5 μg/mL) was removed after incubation with Pseudomonas poae JSU-Y1 in liquid medium at 30 °C for 72 h. When challenged with apple juice, 79% of patulin could be degraded by this isolated strain. Additionally, ascladiol was tentatively identified as the patulin degradation intermediate by LC-MS analysis. Taken together, the experiment results indicated that the isolated Pseudomonas poae JSU-Y1 would be a promising bacterial resource to control patulin contamination and toxigenic fungal growth in agricultural products.

Objectives To provide a basis for clinical management decisions in Paecilomyces variotii infection. Methods Unpublished cases of invasive P. variotii infection from the FungiScope® registry and all cases reported in the literature were analysed. Results We identified 59 cases with P. variotii infection. Main baseline factors were presence of indwelling devices in 29 cases (49.2%), particularly peritoneal catheters (33.9%) and prosthetic heart valves (10.2%), haematological or oncological diseases in 19 (32.2%), major surgery in 11 (18.6%), and diabetes mellitus in 10 cases (16.9%). The most prevalent infection sites were peritoneum (n = 20, 33.3%) and lungs (n = 16, 27.1%). Pain and fever were frequent (n = 35, 59.3% and n = 33, 55.9%, respectively). Diagnosis was established by culture in 58 cases (98.3%). P. variotii caused breakthrough infection in 8 patients. Systemic antifungals were given in 52 patients (88.1%). Amphotericin B was administered in 39, itraconazole in 15, and posaconazole in 8 patients. Clinical isolates were frequently resistant to voriconazole, whereas the above-mentioned antifungals showed good in vitro activity. Infections of the blood and CNS caused high mortality. Overall mortality was 28.8% and death was attributed to P. variotii in 10 cases. Conclusions P. variotii causes life-threatening infections, especially in immunocompromised and critically ill patients with indwelling devices. Patients undergoing peritoneal dialysis are at particular risk. Multidisciplinary management is paramount, including molecular techniques for diagnosis and treatment with efficacious systemic antifungals. Amphotericin B, itraconazole and posaconazole are regarded as treatments of choice. Combination with flucytosine may be considered. Surgical debridement and removal of indwelling devices facilitate favourable outcome.

The global challenge to prevent fungal spoilage and mycotoxin contamination on foods and feeds require the development of new antifungal strategies. Filamentous fungi encode diverse antifungal proteins (AFPs), which offer a great potential for the control of contaminant fungi. In this study, four AFPs from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC) belonging to classes A, B and C, were tested against a representative panel of mycotoxin-producing fungi. They included a total of 38 strains representing 32 different species belonging to the genera Alternaria, Aspergillus, Byssochlamys, Fusarium and Penicillium. PeAfpA exhibited a potent antifungal activity, since the growth of all tested fungi was completely inhibited by concentrations ranging from 0.5 to 16 μg/mL. PdAfpB and PeAfpB, although less effective than PeAfpA, showed significant activity against most of the mycotoxigenic fungi tested. Importantly, PeAfpC previously described as inactive, showed a powerful inhibition against B. spectabilis strains, which are important spoilage and mycotoxin fungi in pasteurized foods. Although less effective than in liquid media, AFPs affected fungal growth on solid media. This study also underlines the potential of these AFPs, in particular PeAfpA, as future antifungal agents for applications in foods, on growing crops or during postharvest storage.

The horizontal transfer of large gene clusters by mobile elements is a key driver of prokaryotic adaptation in response to environmental stresses. Eukaryotic microbes face similar stresses; however, a parallel role for mobile elements has not been established. A stress faced by many microorganisms is toxic metal ions in their environment. In fungi, identified mechanisms for protection against metals generally rely on genes that are dispersed within an organism's genome. Here, we discover a large (∼85 kb) region that confers tolerance to five metal/metalloid ions (arsenate, cadmium, copper, lead, and zinc) in the genomes of some, but not all, strains of a fungus, Paecilomyces variotii. We name this region HEPHAESTUS (Hφ) and present evidence that it is mobile within the P. variotii genome with features characteristic of a transposable element. HEPHAESTUS contains the greatest complement of host-beneficial genes carried by a transposable element in eukaryotes, suggesting that eukaryotic transposable elements might play a role analogous to bacteria in the horizontal transfer of large regions of host-beneficial DNA. Genes within HEPHAESTUS responsible for individual metal tolerances include those encoding a P-type ATPase transporter-PcaA-required for cadmium and lead tolerance, a transporter-ZrcA-providing tolerance to zinc, and a multicopper oxidase-McoA-conferring tolerance to copper. In addition, a subregion of Hφ confers tolerance to arsenate. The genome sequences of other fungi in the Eurotiales contain further examples of HEPHAESTUS, suggesting that it is responsible for independently assembling tolerance to a diverse array of ions, including chromium, mercury, and sodium.

One new chromone, lawsozaheer (

Heat-resistant moulds (HRMs) pose great challenges to processors of fruit-based products due to their thermal resistance and ability to grow across a broad range of conditions. Therefore, the quantification of the effect of inhibitory factors (conditions) on the growth of HRMs is very important to be used to prevent spoilage during shelf-life. This study assessed the minimum temperature and maximum sugar content (°Brix) for the growth of six HRMs (Byssochlamys spp. and Neosartorya spp.) previously isolated from fruit products. In addition, the time to form a visible colony (tv, days) was determined to assess biological variability of individual ascospores within same population. Heat activated ascospores (10 min at 80 °C) were spread plated (±100 spores) on acidified Potato Dextrose Agar (aPDA, pH 3.5) plates from which the °Brix was adjusted with fructose-glucose (1:1) to levels between 44 and 59 °Brix followed by incubation at 30 °C. To assess the effect of temperature, inoculated plates of aPDA were incubated at 4, 7, 8, 10, 12 and 14 °C. Three replicates (= 3 aPDA plates) were prepared per condition evaluated. The number of visible colonies were counted daily for up to two months. Probability distribution functions were then fitted in @Risk to the cumulative tv's. With regards to cold tolerance, B. nivea was the most cold sensitive as it had the least ability to germinate and form visible colonies at low temperatures (no growth when T ≤ 10 °C). On the other hand, N. hiratsukae was the most cold tolerant, being able to form visible colonies at temperatures ≥ 7 °C. Likewise, B. nivea was the most sensitive to increased °Brix values, whilst N. udagawae was able to grow out at the highest °Brix evaluated (59°/aw = 0.86). The tolerance of potential spoilage HRMs to high sugar levels and their ability to grow under chilled conditions represent a challenge for the microbial stability of high-sugar fruit products. Differences in individual tv's were mostly observed under conditions at the growth/no growth regions. For instance, individual tv's of B. nivea ascospores ranged from 24 to 46 days at 12 °C and those of N. udagawae ranged from 20 to 45 days at 59°Brix. The tv's data from each HRM and condition evaluated were then fitted to different statistical distributions (Exponential, Normal, Lognormal, Weibull, Logistic or Pareto) to allow the use of the obtained data in further Quantitative Microbial Spoilage Risk Assessment work for pasteurized fruit products.

Heat resistance of fungi is determined by their sexual spores—ascospores. Their ability to survive common conservation (70 °C 30 min) is of concern for public health and economy as well. Byssochlamys spp., Neosartorya fischeri, and Talaromyces flavus are predominant heat resistant molds. We isolated some more rare representatives from soil: Eupenicillium spp., other Talaromyces spp., including Dichotomomyces cejpii. Byssochlamys spp. are able to synthetize a mycotoxin patulin, often found in canned fruit products together with a wide spectrum of decomposing enzymes. Tremorgenic mycotoxins, byssochlamic acid, etc., might occur in moldy matrices as well. So far, Ag nanoparticles (NPs) and magnetic graphene oxide nanocomposite were successfully applied to eliminate heat resistant fungi from the samples treated. Accurate nanomaterial-assisted aptasensors with CeO2, Au, Ag, and ZnONPs or nanotubes were introduced for ochratoxin A analysis in the last years. Paper-based low-cost sensors as alternatives to conventional methods for field analysis of fungi are emerging recently as well.

Patulin, a poisonous compound produced by Aspergillus, Byssochlamys, and Penicillium, is widely existed in fruits. The control of patulin has always been an important aspect in fruit products processing. As a kind of probiotic, lactic acid bacteria have been usually applied to the fermentation of many kinds of fruit juice, and exhibit promising access on patulin control for its high efficiency and safety. This article aims to screen probiotic strains that have a good capacity for patulin control during juice fermentation. In this study, six LAB strains were used for the fermentation of apple juice, and their ability for the removal of patulin in apple juice fermentation and in vitro digestive model were evaluated. The results indicated that all tested strains were eligible for apple juice fermentation. During this process, 53.14 % of patulin in apple juice (500 μg/L) can be detoxified by Lactobacillus pentosus (DSM 20314) in 24 h and that of the other strains were in the ranging of 13.3%–30.34 %. And in vitro digestive model, all the strains reduced 17.6%–44.2 % of patulin. The stability testing further determined that the removal of patulin was mainly carried out by degradation. Based on this, the optimized test results revealed that with the inoculation proportion of 5 % and shaking incubation, patulin spiked in apple juice can be effectively degraded by L. pentosus (DSM 20314), which has a good fermentation performance and exhibits a great potential in patulin control during apple juice fermentation and digestion.

Low-energy electron beam was investigated as an intervention strategy for the reduction of spores of food-spoiling fungi. Inactivation kinetics of five strains from the genera Aspergillus, Byssochlamys, Eurotium and Penicillium were determined. A two-dimensional membrane was used as a model system to exclude matrix effects. Raisins were incorporated into the study as an example of a three-dimensional food surface structure that is regularly being affected by spoilage through moulds. Complete inactivation could be attained on the model system after a maximum dose of 6 kGy, whereas between 1.04 and 1.71 log reductions were achieved on raisins. This novel application of low-energy electron beam was shown to reduce mould spores even on challenging food surfaces, paving the way for implementation in food industry., Food Control, 92

The major aims of this study were to assess inter- and intra-species variability of heat resistant moulds (HRMs), Byssochlamys fulva and Byssochlamys nivea, with regards to (i) heat resistance and (ii) effect of heat treatment intensity on subsequent outgrowth. Four-week-old ascospores were suspended in buffered glucose solution (13° Brix, pH 3.5) and heat treated in a thermal cycler adjusted at 85 °C, 90 °C and 93 °C. Two variants of the Weibull model were fitted to the survival data and the following inactivation parameters estimated: b (inactivation rate, min-1), n (curve shape) and δ (the time taken for first decimal reduction, min). In addition to the assessment of heat resistance, outgrowth of Byssochlamys sp. from ascospores heated at 70 °C, 75 °C, 80 °C, 85 °C and 90 °C for 10 min and at 93 °C for 30 and 70 s was determined at 22 °C for up to 30 days. The Baranyi and Roberts model was fitted to the growth data to estimate the radial growth rates (μmax, mm.day-1) and lag times (λ, days). Inter-species variability and significant differences (p < 0.05) were observed for both inactivation and growth estimated parameters among B. fulva and B. nivea strains. The effect of heat treatment intensity on outgrowth of B. fulva strains was more apparent at the most intense heat treatment evaluated (90 °C/10 min), which was also the condition in which greater dispersion of the estimated kinetic parameters was observed. On the other hand, B. nivea strains were more affected by heating, resulting in greater variability of growth parameters estimated at different heating intensities and in very long lag phases (up to 25 days). The results show that inter- and intra-species variability in the kinetic parameters of Byssochlamys sp. needs to be taken into account for more accurate spoilage prediction. Furthermore, the effect of thermal treatments on subsequent outgrowth from ascospores should be explored in combination with other relevant factors such as °Brix and oxygen to develop thermal processes and storage conditions which can prevent the growth of HRMs and spoilage of heat treated food products.

Bysspectin A (1), a polyketide-derived octaketide dimer with a novel carbon skeleton, and two new precursor derivatives, bysspectins B and C (2 and 3), were obtained from an organic extract of the endophytic fungus Byssochlamys spectabilis that had been isolated from a leaf tissue of the traditional Chinese medicinal plant Edgeworthia chrysantha, together with a known octaketide, paecilocin A (4). Their structures were determined by HRMS, 1D and 2D NMR spectroscopic analysis. A plausible route for their biosynthetic pathway is proposed. Compounds 1–3 were tested for their antimicrobial activities. Only compound 3 was weakly active against Escherichia coli and Staphyloccocus aureus with MIC values of 32 and 64 μg/mL, respectively. Further, the inhibitory effects on human carboxylesterases (hCE1, hCE2) of compounds 1 and 4 were evaluated. The results demonstrated that bysspectin A (1) was a novel and highly selective inhibitor against hCE2 with the IC50 value of 2.01 μM. Docking simulation also demonstrated that active compound 1 created interaction with the Ser-288 (the catalytic amino-acid in the catalytic cavity) of hCE2 via hydrogen bonding, revealing its highly selective inhibition toward hCE2.

Fungal community and non-volatile metabolites changes during the pile-fermentation are key factors to organoleptic qualities of dark green tea. However, the correlation between fungal succession and non-volatile compounds has never been satisfactorily explained. The purpose of the present study was to investigate fungal succession and its correlation with flavor compounds by multi-omics. Illumina Miseq sequencing of ITS1 region was conducted to analyze the fungal succession, a total of 78 OTUs which consisted of one phyla, nine classes, 15 orders, 26 families, 37 genera were identified, with Ascomycota as dominant phyla. Cluster analysis and non-metric multidimensional scaling of samples demonstrated the distribution of OTUs in multi-dimensional space, the pile-fermentation process of dark green tea can be divided into four periods according to the generated trajectory of fungal population, S0, S1-S3, S4-S5, and S6. Aspergillus is the dominant genus. Penicillium, Cyberlindnera, Debaryomyces, Candida, Thermomyces, Rasamsonia, Thermoascus, and Byssochlamys appear in different periods. three alkaloids, seven catechins, nine amino acids, five organic acids, five flavones and flavonoid glycosides were identified by UPLC-QTOF-MS/MS, and the contents were all decreasing. Caffeine, EGC, EGCG, L-theanine, kaempferitrin, L-phenylalanine, gallic acid, and myricetin-3-O-galactoside are important ingredients which contribute to the flavor of dark green tea. This study demonstrated the fungal succession, non-volatile flavor compounds and their relationships during pile-fermentation of dark green tea, and provides new insights into evaluating pivotal role of fungal succession in the manufacturing process of dark green tea.