Umbelopsis Isabellina Research Articles

Hormesis and Low Toxic Effects of Three Lanthanides in Microfungi Isolated from Rare Earth Mining Waste in Northwestern Russia.

The low-dose toxicity of chloride and nitrate salts of three lanthanides (La, Ce and Nd) was tested on six microfungal species. Five of them (Geomyces vinaceus, Aspergillus niveoglaucus, Pseudogymnoascus pannorum, Penicillium simplicissimum and Umbelopsis isabellina) were isolated from the loparite ore tailings on the Kola Peninsula, northwestern Russia. Sydowia polyspora was a control strain. In the case of nitrate salts, the toxicity of REEs to four of six microorganisms was significantly (p < 0.5) lower compared to chloride salts. In this case, nitrates can play the role of exogenous nutrients, compensating for the toxic effect of REEs. Interestingly, U. isabellina only showed an opposite response, indicating the highest toxicity of nitrate (IC5 = 9-20 mg/L) REEs' salts compared to chlorides (IC5 = 80-195 mg/L) at low concentration levels. In addition, treatment with lanthanides showed a "hormesis effect" on fungal growth with stimulation at low doses and inhibition at high doses. However, U. isabellina and S. polyspora demonstrated the absence of hormetic response under the treatment of REEs' nitrate salt. Taking into account the specific hormetic responses and high tolerance of P. simplicissimum and U. isabellina to lanthanides, our findings may be useful in the assessment of the potential application of the selected fungi to bioremediation and REE bioleaching.

Solid-state fermentation with Zygomycetes fungi as a tool for biofortification of apple pomace with γ-linolenic acid, carotenoid pigments and phenolic antioxidants

In the last few years, there has been a growing interest in the more efficient utilization of agricultural and food by-products. Apples are among the most processed fruits in the world that generate huge quantities of processing waste biomasses. Therefore, the objective of this study was to improve the nutritional value of apple pomaces with γ-linolenic acid (GLA) and carotenoid pigments by solid-state fermentation (SSF) using two Zygomycetes fungi (Actinomucor elegans and Umbelopsis isabellina). The impact of fermentation periods on the polyphenol content and antioxidant capacity of the bioprocessed apple pomace was also investigated. The accumulated lipids were composed primarily of neutral fractions (mostly triacylglycerols). SSF with U. isabellina yielded a 12.72% higher GLA content than with A. elegans (3.85 g GLA/kg DW of pomace). Contrary to the lipogenic capacity, A. elegans showed higher carotenoids and phenolic antioxidants productivity than U. isabellina. The maximum concentrations for β-carotene (433.11 μg/g DW of pomace-SSF with A. elegans and 237.68 μg/g DW of pomace-SSF with U. isabellina), lutein (374.48 μg/g DW- A. elegans and 179.04 μg/g DW- U. isabellina) and zeaxanthin (247.35 μg/g DW- A. elegans and 120.41 μg/g DW- U. isabellina) were registered on the 12th day of SSFs. In the case of SSF with A. elegans, the amount of total phenolics increased significantly (27%) by day 4 from the initial value (2670.38 μg of gallic acid equivalents/g DW) before slowly decreasing for the remaining period of the fungal growth. The experimental findings showed that a prolonged fermentation (between 8 and 12 days) should be applied to obtain value-added apple pomaces (rich in GLA and carotenoids) with potential pharmaceutical and functional food applications. Moreover, the SSF processes of simultaneous bioaccumulation of valuable fatty acids, carotenoids and phenolic antioxidants proposed in the present study may open up new challenges for biotechnological production of industrially important biomolecules using abundant and unexploited apple pomaces.

Tolerance of Rare-Earth Elements in Extremophile Fungus Umbelopsis isabellina from Polar Loparite Ore Tailings in Northwestern Russia

In this study, extremophile fungal species isolated from pure loparite-containing sands and their tolerance/resistance to the lanthanides Ce and Nd were investigated. The loparite-containing sands were collected at the tailing dumps of an enterprise developing a unique polar deposit of niobium, tantalum and rare-earth elements (REEs) of the cerium group: the Lovozersky Mining and Processing Plant (MPP), located in the center of the Kola Peninsula (northwestern Russia). From the 15 fungal species found at the site, one of the most dominant isolates was identified by molecular analysis as the zygomycete fungus Umbelopsis isabellina (GenBank accession no. OQ165236). Fungal tolerance/resistance was evaluated using different concentrations of CeCl3 and NdCl3. Umbelopsis isabellina exhibited a higher degree of tolerance/resistance to cerium and neodymium than did the other dominant isolates (Aspergillus niveoglaucus, Geomyces vinaceus and Penicillium simplicissimum). The fungus began to be inhibited only after being exposed to 100 mg L-1 of NdCl3. The toxic effects of Ce were not observed in fungus growth until it was subjected to 500 mg∙L-1 of CeCl3. Moreover, only U. isabellina started to grow after extreme treatment with 1000 mg∙L-1 of CeCl3 one month after inoculation. This work indicates, for the first time, the potential of Umbelopsis isabellina to remove REEs from the loparite ore tailings, making it a suitable candidate for the development of bioleaching methods.

Studies on the co-metabolism of glucose and glycerol in the fungus Umbelopsis isabellina

Over the past few years, it is observed an increased interest for oleaginous microorganisms in the perspective to produce microbial oils of great commercial interest through the consumption of low/zero cost substrates. In this paper, the physiology of the fungus Umbelopsis isabellina growing on blends of glycerol and glucose was investigated. In all experiments the fungus completely consumed glucose and produced satisfactory quantities of biomass containing reserve lipids in high percentages. However, glycerol concentration in the growth medium was negatively correlated to glucose assimilation rate, mainly during the balanced-growth phase. Nevertheless, at high initial concentrations, glycerol was partially consumed and seemed to contribute positively to the suppression of lipid degradation. Following the discovery of this complex regulatory mechanism regarding glucose and glycerol co-assimilation, the activity of three key-enzymes namely aldolase, glycerol kinase and glycerol dehydrogenase, which are implicated in glycerol and glucose assimilation, was investigated. The experiments revealed a clear preference of the fungus for glucose over glycerol. On the other hand, storage polysaccharides are degraded instead of storage lipid at the late oleaginous phase for maintenance purpose. These new biochemical features will enable the design of appropriate growth media for the co-fermentation of these two substrates by U. isabellina with the aim to maximize lipid accumulation.

Biological Synthesis of Monodisperse Uniform-Size Silver Nanoparticles (AgNPs) by Fungal Cell-Free Extracts at Elevated Temperature and pH.

Fungi’s ability to convert organic materials into bioactive products offers environmentally friendly solutions for diverse industries. In the nanotechnology field, fungi metabolites have been explored for green nanoparticle synthesis. Silver nanoparticle (AgNP) research has grown rapidly over recent years mainly due to the enhanced optical, antimicrobial and anticancer properties of AgNPs, which make them extremely useful in the biomedicine and biotechnology field. However, the biological synthesis mechanism is still not fully established. Therefore, this study aimed to evaluate the combined effect of time, temperature and pH variation in AgNP synthesis using three different fungi phyla (Ascomycota, Basidiomycota and Zygomycota) represented by six different fungi species: Cladophialophora bantiana (C. bantiana), Penicillium antarcticum (P. antarcticum), Trametes versicolor (T. versicolor), Trichoderma martiale (T. martiale), Umbelopsis isabellina (U. isabellina) and Bjerkandera adusta (B. adusta). Ultraviolet–visible (UV-Vis) spectrophotometry and transmission electron microscopy (TEM) results demonstrated the synthesis of AgNPs of different sizes (3 to 17 nm) and dispersity percentages (25 to 95%, within the same size range) using fungi extracts by changing physicochemical reaction parameters. It was observed that higher temperatures (90 °C) associated with basic pH (9 and 12) favoured the synthesis of monodisperse small AgNPs. Previous studies demonstrated enhanced antibacterial and anticancer properties correlated with smaller nanoparticle sizes. Therefore, the biologically synthesised AgNPs shown in this study have potential as sustainable substitutes for chemically made antibacterial and anticancer products. It was also shown that not all fungi species (B. adusta) secrete metabolites capable of reducing silver nitrate (AgNO3) precursors into AgNPs, demonstrating the importance of fungal screening studies.

Ecotoxicological Estimation of 4-Cumylphenol, 4-t-Octylphenol, Nonylphenol, and Volatile Leachate Phenol Degradation by the Microscopic Fungus Umbelopsis isabellina Using a Battery of Biotests.

The phenolic xenobiotics nonylphenol (NP), 4-tert-octylphenol (4-t-OP), and 4-cumylphenol (4-CP) have the potential to seriously disrupt the endocrine system. Volatile phenols (VPs), especially those present in landfill leachate, also adversely affect the health of numerous organisms. Microbial degradation of xenobiotics can result in the formation of intermediates with higher toxicity than the precursor substrates. Therefore, the main aim of this study was to assess the changes in environmental ecotoxicity during the biotransformation of nonylphenol, 4-tert-octylphenol, 4-cumylphenol and volatile phenols by Umbelopsis isabellina using a battery of biotests. The application of bioindicators belonging to different taxonomic groups and diverse trophic levels (producers, consumers, and reducers) indicated a significant reduction in toxicity during the cultivation of fungus cultures both for nonylphenol, 4-tert-octylphenol, 4-cumylphenol and volatile phenols. The rate of toxicity decline was correlated with the degree of xenobiotic biotransformation. Removal of 4-cumylphenol and 4-tert-octylphenol also led to a decrease in the anti-androgenic potential. Moreover, this is the first report demonstrating the anti-androgenic properties of 4-cumylphenol. The results showed that U. isabellina is an attractive tool for the bioremediation and detoxification of contaminated environments.

Strategy to increase the lipid stability of the microbial oil produced by Umbelopsis isabellina for food purposes: Use of microencapsulation by external ionic gelation

Oleaginous microorganisms, including the fungus Umbelopsis isabellina, have emerged as a biotechnological alternative to obtain polyunsaturated fatty acid-rich oils, which are strongly linked to energy purposes (biofuel) than the food industry. Considering the composition of microbial oil and its use by the food industry, it is necessary to investigate strategies that increase its lipid stability. Ergo, this pioneering study aimed to microencapsulate the oil produced by Umbelopsis isabellina and evaluate its oxidative stability throughout the storage period against factors such as temperature and luminosity. The microbial oil was microencapsulated through the external ionic gelation technique, producing an encapsulation efficiency of 80% and proving to be a suitable method because it maintained oil composition. Combining microencapsulation and refrigerated storage led to the best effects on storage time, increasing the evaluated lipid stability through the peroxide values and conjugated diene formation. Moreover, saturated and monounsaturated fatty acid content increased, and polyunsaturated fatty acid content decreased during storage for both the free and microencapsulated oil, regardless of storage temperature, although microencapsulation reduced the changes. The results primarily demonstrate how microencapsulation prolongs the oxidative stability and unsaturated fatty acid content of the microbial oil by reducing its reactions to external environmental factors, thus facilitating its use in the food industry.

Mycobiota of the upper layer of pine forests litter in the parks of Surgut in the environmental assessment of anthropogenic impact on these territories

The paper studies mycobiota of the upper layer of pine forests litter in the parks of Surgut: Za Saimoy, Energetikov, Kedrovy Log, Neftyanik. The author identified 52 isolates of soil microscopic fungi belonging to 14 genera. Most of the isolates anamorphic (mitospore) fungi are represented by 9 genera: Acremonium, Annellosporium, Aspergillus, Fusarium, Humicola, Penicillium, Trichoderma, Ulocladium, Verticillium. Zygomycetes belong to three genera Absidia, Mucor and Umbelopsis. Ascomycetes are represented by two genera: Eupenicillium and Talaromyces. The author also isolated Mycelia sterilia group. Representatives of the genera Absidia, Trichoderma, Fusarium and Penicillium are found in the mycocenoses of the studied parks. The genera Trichoderma, Fusarium and Penicillium also dominate by the number of isolates. Umbelopsis isabellina species is abundant in the Kedrovy Log park. Species of the genus Trichoderma are abundant in the Neftyanik park. Light-colored micromycetes of the group Mycelia sterilia are found and abundant only in the Za Saimoy park. Cellulolytics of the genus Trichoderma and the species Annellosporium nemorosum are abundant in the Energetikov park. Thus, mycobiota of the upper layer litter of the studied parks is close to the mycobiota of the background podzolic soils. It contains fungal species typical of the background soils. Fungi resistant to anthropogenic influences dark-colored micromycetes Ulocladium alternarie and phytopathogenic species Verticillium dahlia var. longisporum. were found in the minority only in the Energetikov park. The obtained data allow us to conclude that the anthropogenic influence on the structure of the mycocenosis of the Energetikov park is more pronounced, but in general it does not have a significant effect on the mycobiota of the upper layer litter of the studied parks.

Isolation and Identification of Fungi Associated with Decay of Quercus mongolica

The Quercus mongolica has a high utilization value in industrial economic sector. The species is distributed throughout Korea, however, the damage caused by deterioration such as discoloration and decay is severe. For this reason, the deterioration of Q. mongolica is an obstacle to its use as wood, but research on deterioration factors is insufficient. In this study, we focused on fungi as a factor influencing the deterioration of Q. mongolica, and isolated and identified the fungi from the deteriorated Q. mongolica. In additions, in order to confirm whether the identified fungi actually affects wood deterioration, enzyme activities of the identified fungi were evaluated and related mass loss of wood treated with the fungi was measured by wood decay test. As a result of sequencing analysis using the ITS region of the genomic DNA of the fungi isolated from Q. mongolica, Mucor circinelloides, Cunninghamella elegans, and Umbelopsis isabellina 3 species belonging to Mucoromycota phylum, and Ophiostoma piceae and Aureobasidium melanogenum 2 species belonging to Ascomycota phylum were identified. These five fungi had enzyme (i.e. cellulase, laccase) activities related to wood decay and reduced the mass of heartwood and sapwood of Q. mongolica in practice. In particular, O. piceae and A. melanogenum, which have both cellulase and laccase activities, showed 6.9% and 1.5% mass loss, respectively. These results indicated that five fungi identified in this study influence the deterioration of Q. mongolica and are wood decaying fungi for Q. mongolica potentially.

Enzymatic Synthesis of Glucose Fatty Acid Esters Using SCOs as Acyl Group-Donors and Their Biological Activities

Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in food, cosmetic and pharmaceutical industries. In this research, the fatty acid moieties derived from polyunsaturated fatty acids containing single-cell oils (SCOs) (i.e., those produced from Cunninghamella echinulata, Umbelopsis isabellina and Nannochloropsis gaditana, as well as from olive oil and an eicosapentaenoic acid (EPA) concentrate) were converted into GEs by enzymatic synthesis, using lipases as biocatalysts. The GE synthesis was monitored using thin-layer chromatography, FTIR and in situ NMR. It was found that GE synthesis carried out using immobilized Candida antarctica B lipase was very effective, reaching total conversion of reactants. It was shown that EPA-GEs were very effective against several pathogenic bacteria and their activity can be attributed to their high EPA content. Furthermore, C. echinulata-GEs were more effective against pathogens compared with U. isabellina-GEs, probably due to the presence of gamma linolenic acid (GLA) in the lipids of C. echinulata, which is known for its antimicrobial activity, in higher concentrations. C. echinulata-GEs also showed strong insecticidal activity against Aedes aegypti larvae, followed by EPA-GEs, olive oil-GEs and N. gaditana-GEs. All synthesized GEs induced apoptosis of the SKOV-3 ovarian cancer cell line, with the apoptotic rate increasing significantly after 48 h. A higher percentage of apoptosis was observed in the cells treated with EPA-GEs, followed by C. echinulata-GEs, U. isabellina-GEs and olive oil-GEs. We conclude that SCOs can be used in the synthesis of GEs with interesting biological properties.

Animal Fat as a Substrate for Production of n-6 Fatty Acids by Fungal Solid-State Fermentation.

The method of solid-state fermentation (SSF) represents a powerful technology for the fortification of animal-based by-products. Oleaginous Zygomycetes fungi are efficient microbial cell factories used in SSF to valorize a wide range of waste and rest cereal materials. The application of this fermentation technique for utilization and biotransformation of animal-based materials represents a distinguished step in their treatment. In this study, for the first time, the strain Umbelopsis isabellina CCF2412 was used for the bioconversion of animal fat by-products to the fermented bioproducts enriched with n-6 polyunsaturated fatty acids, mainly γ-linolenic acid (GLA). Bioconversion of both cereals and the animal fat by-product resulted in the production of fermented bioproducts enriched with not just GLA (maximal yield was 6.4 mg GLA/g of fermented bioproduct), but also with high yields of glucosamine. Moreover, the fermentation on the cornmeal matrix led to obtaining bioproduct enriched with β-carotene. An increased amount of β-carotene content improved the antioxidant stability of obtained fermented bioproducts. Furthermore, the application of Fourier-transform infrared spectroscopy for rapid analysis and characterization of the biochemical profile of obtained SSF bioproducts was also studied.

Single Cell Oil (SCO)-Based Bioactive Compounds: I-Enzymatic Synthesis of Fatty Acid Amides Using SCOs as Acyl Group Donors and Their Biological Activities.

Fatty acid amides (FAAs) are of great interest due to their broad industrial applications. They can be synthesized enzymatically with many advantages over chemical synthesis. In this study, the fatty acid moieties of lipids of Cunninghamella echinulata ATHUM 4411, Umbelopsis isabellina ATHUM 2935, Nannochloropsis gaditana CCAP 849/5, olive oil, and an eicosapentaenoic acid (EPA) concentrate were converted into their fatty acid methyl esters and used in the FAA (i.e., ethylene diamine amides) enzymatic synthesis, using lipases as biocatalysts. The FAA synthesis, monitored using in situ NMR, FT-IR, and thin-layer chromatography, was catalyzed efficiently by the immobilized Candida rugosa lipase. The synthesized FAAs exhibited a significant antimicrobial activity, especially those containing oleic acid in high proportions (i.e., derived from olive oil and U. isabellina oil), against several human pathogenic microorganisms, insecticidal activity against yellow fever mosquito, especially those of C. echinulata containing gamma-linolenic acid, and anticancer properties against SKOV-3 ovarian cancer cell line, especially those containing EPA in their structures (i.e., EPA concentrate and N. gaditana oil). We conclude that FAAs can be efficiently synthesized using microbial oils of different fatty acid composition and used in specific biological applications.

Maximization of microbial oil containing polyunsaturated fatty acid production by Umbelopsis (Mortierella) isabellina

Abstract Filamentous fungi, such as Umbelopsis isabellina, produce oils rich in monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), which are essential nutrients that regulate the physiological processes necessary for human health and development. Therefore, this study aimed to optimize the microbial oil production of Umbelopsis isabellina by maximizing lipid and PUFA production under different forms of cultivation. The best production conditions in shake flasks (250 mL) were evaluated by analyzing three different culture medium components (yeast extract, peptone, and sucrose) and three fermentation parameters (stirring rate, temperature, and pH). In this cultivation form, the optimal condition had a lipid yield of 31.77%, of which 16.68% were PUFA. Subsequently, to assess the best condition in a 2.5 L agitated tank bioreactor (STR), stirring and aeration rates were also evaluated using a central composite rotatable design (CCRD), and the optimized condition resulted in a lipid yield of 36.58%, of which 14.88% are PUFA. Fifteen fatty acids were identified, and the main ones (decreasing order) were oleic (47%), palmitic (27%), linoleic (11%), and γ-linolenic (5%) acids. The microbial oil produced has a good fatty acid profile with prominent presence of fatty acids of the n-6 family (linoleic and γ-linolenic acids), and also presence of n-3 family (α-linolenic (ALA), eicosapentaenoic (EPA), and docosahexaenoic acids (DHA)), demonstrating the potential of large-scale lipid production with great potential for use in developing food additives and nutraceutical ingredients.

Production of high-value bioproducts enriched with \u03b3-linolenic acid and \u03b2-carotene by filamentous fungi Umbelopsis isabellina using solid-state fermentations

Solid-state fermentation is a useful tool for utilizing different plant-based materials as cultivation substrates in order to produce potentially high-value fermented bioproducts. The aim of the present study was to successfully prepare various types of such bioproducts, using a zygomycetous strain Umbelopsis isabellina CCF2412. Various legume and cereal substrates were utilized effectively, while a few of them were obtained from agricultural waste, which is particularly advantageous from ecological and economic point of view. A common feature of the produced fermented materials was the increased content of different polyunsaturated fatty acids and carotenoid pigments in these bioproducts. Subsequent to the optimization of the solid-state fermentation process using cornmeal as the cultivation substrate, bioproducts enriched with γ-linolenic acid (11.45 mg γ-linolenic acid per gram of bioproduct), β-carotene (50.90 μg β-carotene per gram of bioproduct), and various microbial sterols were obtained. Appropriate n–6/n–3 acid ratio and enrichment of other microbial substances, such as the pigments and sterols mentioned above, in the fermented bioproducts widens the applicability of these bioproducts in different industries. The fermented cereal bioproducts produced in the present study from fermented wheat bran substrate were used for evaluating their application as feed for broiler chicken, and satisfactory results were obtained. Therefore, the present study creates novel opportunities for improving the quality of fermented bioproducts obtained during solid-state fermentation processes, especially for application in the feed industry.

High diversity of fungi associated with altered wood materials in the hunting lodge of “La Muette”, Saint-Germain-en-Laye, France

“La Muette” is an eighteenth-century hunting lodge located in the forest of Saint-Germain-en-Laye, France. This study consisted in the implementation of multidisciplinary analytical tools to characterize the fungal biocontamination of woods inside the monument. The fungal colonization was first mapped by macroscopic visual observation of all the rooms. Brown rot and white rot present in different rooms and fruiting bodies of Serpula lacrymans were observed on the first and second floors in localized areas. At the same time, air sampling was carried out, and the volatile organic compounds (VOCs) specific to the activity of fungi were analysed by gas chromatography. The analysis of the VOCs confirmed the presence of active developments of moulds and S. lacrymans in the pavilion. Wood samples were collected from areas with visible fungal colonization and subjected to culturing, extraction of DNA and analysis of the ITS sequences after PCR amplification. Culturing and microscopic observation revealed the presence of several moulds: Penicillium sp., Cladosporium sp., Acremonium sp., Humicola sp., Rhizopus sp. and Mucor sp. Isolates not identified by this approach were identified by analysing ITS sequences as Trichoderma atroviride, Engyodontium album and Umbelopsis isabellina. The presence of additional Ascomycota (Acremonium charticola, Aspergillus conicus, Chaetomium elatum, Lecanicillium sp.) and of the Basidiomycota Coprinellus aff. radians was revealed after DNA extraction, amplification and analysis of ITS sequences directly on wood samples. In conclusion, a high fungal diversity including moulds, S. lacrymans and C. aff. radians was demonstrated in association with altered wood in the monument.

Simultaneous enrichment of grape pomace with γ-linolenic acid and carotenoids by solid-state fermentation with Zygomycetes fungi and antioxidant potential of the bioprocessed substrates

Two filamentous fungi (Actinomucor elegans and Umbelopsis isabellina), were tested for their ability to enrich white grape pomace simultaneously with both γ-linolenic acid (GLA) and carotenoids through solid-state fermentation (SSF) processes. U. isabellina presented higher ability to produce GLA-rich lipids (composed mainly of neutral fractions) than A. elegans (the 6-th day of SSF: 378.85 mg/100 g of pomace –U. isabellina and 193.36 mg/100 g of pomace– A. elegans). The amounts of β-carotene and lutein for both SSFs gradually increased until the end of the fermentation processes. The effect of fermentation time on the phenolic content and antioxidant activity of grape pomace was also studied. The SSF with A. elegans increased significantly total phenolic and flavonoid contents and DPPH scavenging activity of grape popmace.These bioprocessed grape pomaces with significant amounts of carotenoids and GLA-rich lipids (>94% nutritionally-valuable polyunsaturated fatty acids at the sn-2 position) could be very attractive for food industry.

Mycological Diversity Description II

ABSTRACT Here, Quambalaria fabacearum and Neopestalotiopsis brasiliensis are introduced as new species from Brazil, isolated as endophyte from Mimosa tenuiflora and causing post-harvest rot disease on fruits of Psidium guajava, respectively. Diaporthe inconspicua is emended to include a more detailed morphological description. Neopestalotiopsis egyptiaca is reported as new to the Americas and as causing post-harvest rot disease on fruits of Psidium guajava, while Umbelopsis isabellina is reported as endophyte.

Detoxification and simultaneous removal of phenolic xenobiotics and heavy metals with endocrine-disrupting activity by the non-ligninolytic fungus Umbelopsis isabellina.

Organic and inorganic pollutants well known to interfere with the major functions of the endocrine system co-occur widely in contaminated ecosystems. The aim of the study was to evaluate the ability of Umbelopsis isabellina fungus to simultaneously remove and detoxify multiple environmentally significant endocrine disruptors: the heavy metals Cd(II), Zn(II), Mn(II), Pb(II) and Ni(II) and the phenolic xenobiotics nonylphenol (t-NP), 4-cumylphenol (CP) and 4-tert-octylphenol (4-t-OP). The effects of the metals on fungal growth and efficiency of single-metal uptake were also investigated. U. isabellina exhibited considerable tolerance to Zn(II), Mn(II), Pb(II) and Ni(II), with IC50/24 values ranging from 5.08 for Ni(II) to 13.1 mM for Zn(II). In the presence of CP, the maximum efficiency of Pb(II) removal increased 25% relative to that of the control. Supplementation with Mn(II) or Zn(II) enhanced the 4-t-OP degradation by 18 or 9%, respectively, after 6 h of cultivation. Ecotoxicological assays monitoring bioindicators from different aquatic ecosystems revealed detoxification coinciding with the removal of metals and organic xenobiotics from binary mixtures. This work indicates the potential of a single microorganism, U. isabellina, to remove both heavy metals and organic xenobiotics from co-contaminated sites, making it a suitable candidate for the development of bioremediation strategies.

2,4-dichlorophenoxyacetic acid-induced oxidative stress: Metabolome and membrane modifications in Umbelopsis isabellina, a herbicide degrader.

The study reports the response to herbicide of the 2,4-dichlorophenoxyacetic acid (2,4-D)–degrading fungal strain Umbelopsis isabellina. A comparative analysis covered 41 free amino acids as well as 140 lipid species of fatty acids, phospholipids, acylglycerols, sphingolipids, and sterols. 2,4-D presence led to a decrease in fungal catalase activity, associated with a higher amount of thiobarbituric acid-reactive substances (TBARS). Damage to cells treated with the herbicide resulted in increased membrane permeability and decreased membrane fluidity. Detailed lipidomic profiling showed changes in the fatty acids composition such as an increase in the level of linoleic acid (C18:2). Moreover, an increase in the phosphatidylethanolamine/phosphatidylcholine ratio was observed. Analysis of fungal lipid profiles revealed that the presence of 2,4-D was accompanied by the accumulation of triacylglycerols, a decrease in ergosterol content, and a considerable rise in the level of sphingolipid ceramides. In the exponential phase of growth, increased levels of leucine, glycine, serine, asparagine, and hydroxyproline were found. The results obtained in our study confirmed that in the cultures of U. isabellina oxidative stress was caused by 2,4-D. The herbicide itself forced changes not only to membrane lipids but also to neutral lipids and amino acids, as the difference of tested compounds profiles between 2,4-D—containing and control samples was consequently lower as the pesticide degradation progressed. The presented findings may have a significant impact on the basic understanding of 2,4-D biodegradation and may be applied for process optimization on metabolomic and lipidomic levels.

Inhibition of virulent and hypovirulent Cryphonectria parasitica growth in dual culture by fungi commonly isolated from chestnut blight cankers

Chestnut blight cankers, caused by the fungus Cryphonectria parasitica, are prone to invasion by other microorganisms as the canker ages. This microbial community has the potential to alter canker expansion, which may influence the probability that the canker girdles the infected stem. Hypoviruses infect the pathogen mycelium directly and are known to decrease pathogen virulence (i.e. hypovirulent). These viral infections can slow pathogen growth, decreasing the rate of canker expansion and lowering the probability of girdling. Saprophytic fungi also invade the expanding canker and may antagonize C. parasitica leading to reduced pathogen growth. The combined effects of fungal antagonism and a hypovirulent pathogen could work in combination to reduce the probability of girdling the infected stem. We assessed the ability of different fungal taxa, isolated from low severity cankers, to inhibit the growth of virulent and hypovirulent forms of C. parasitica in dual culture tests on two cultural media. Percent growth inhibition of virulent C. parasitica by potentially antagonistic fungi ranged from 2 % to 34 %, while inhibition of hypovirulent C. parasitica ranged from 18 % to 54 %. Only one isolate, identified as Umbelopsis isabellina (UmbelopsisWS) inhibited the virulent form of the pathogen more than the hypovirulent form. All three Trichoderma isolates caused the greatest growth inhibition of virulent C. parasitica, but they, like all other fungal isolates tested, inhibited the hypovirulent form of the pathogen more than the virulent form. These results suggest that commonly occurring fungi in chestnut blight cankers, including Trichoderma, may inhibit the hypovirulent C. parasitica more than virulent C. parasitica. Thus, the presence of other fungi in cankers may not enhance the effect of hypovirulent C. parasitica to delay cankers from girdling a stem but instead intensify canker development.