Bioactivity and Mycochemical Profile of Extracts from Mycelial Cultures of Ganoderma spp.

Fungal mycelium cultures are an alternative to natural sources in order to obtain valuable research materials. They also enable constant control and adaptation of the process, thereby leading to increased biomass growth and accumulation of bioactive metabolites. The present study aims to assess the biosynthetic potential of mycelial cultures of six Ganoderma species: G. adspersum, G. applanatum, G. carnosum, G. lucidum, G. pfeifferi, and G. resinaceum. The presence of phenolic acids, amino acids, indole compounds, sterols, and kojic acid in biomass extracts was determined by HPLC. The antioxidant and cytotoxic activities of the extracts and their effects on the inhibition of selected enzymes (tyrosinase and acetylcholinesterase) were also evaluated. The total content of phenolic acids in the extracts ranged from 5.8 (G. carnosum) to 114.07 mg/100 g dry weight (d.w.) (G. pfeifferi). The total content of indole compounds in the extracts ranged from 3.03 (G. carnosum) to 11.56 mg/100 g d.w. (G. lucidum) and that of ergosterol ranged from 28.15 (G. applanatum) to 74.78 mg/100 g d.w. (G. adspersum). Kojic acid was found in the extracts of G. applanatum and G. lucidum. The tested extracts showed significant antioxidant activity. The results suggest that the analyzed mycelial cultures are promising candidates for the development of new dietary supplements or pharmaceutical preparations.

Assessing the Fungal Simultaneous Removal Efficiency of Carbamazepine, Diclofenac and Ibuprofen in Aquatic Environment

Unused pharmaceutical compounds (PhCs) discharged into the aquatic environment have been regarded as emerging pollutants due to potential harmful effects on humans and the environment. Microbial bioremediation is considered as a viable option for their removal from wastewater. The aim of this study was to assess the simultaneous removal of carbamazepine (CBZ), diclofenac (DCF) and ibuprofen (IBP) by previously isolated fungi (Aspergillus niger, Mucor circinelloides, Trichoderma longibrachiatum, Trametes polyzona, and Rhizopus microsporus). The tolerance to PhCs was conducted by tracking the fungal mycelium mat diameters in solid media and its dry biomass in liquid media, at the drug concentration range of 0.1 to 15 mg/L. The fungal enzymatic activities were determined for lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase (Lac), respectively. The PhC removal efficiency of the fungi was assessed in aerated batch flasks and the drug concentrations and intermediate compounds formation were determined by using SPE-UPLC/MS. A tolerance over 70% was recorded for all the fungi at drug concentration of 0.1 mg/L. Manganese peroxidase was produced by all the fungi with very low amount of LiP, while all the enzymes were produced by T. polyzona. The pH of 4.3, temperature 37 ± 1.5°C and incubation time of 6 days were the optimum parameters for the fungal enzymatic activities. The best removal of CBZ (87%) was achieved by R. microsporus after 10 days. Between 78 and 100% removal of DCF was observed by all the fungi after 24 h, while 98% of IBP was removed after 2 days by M. circinelloides. Only a few intermediate compounds were identified after 3 days and disappeared after 10 days of incubation. This study demonstrated that apart from the basidiomycetes, the ascomycetes and zygomycetes are also producers of ligninolytic enzymes and have the ability to biodegrade emerging pollutants such as PhCs.

Membrane lipid and osmolyte readjustment in the alkaliphilic micromycete Sodiomyces tronii under cold, heat and osmotic shocks

Previously, we showed for the first time that alkaliphilic fungi, in contrast to alkalitolerant fungi, accumulated trehalose under extremely alkaline conditions, and we have proposed its key role in alkaliphilia. We propose that high levels of trehalose in the mycelium of alkaliphiles may promote adaptation not only to alkaline conditions, but also to other stressors. Therefore, we studied changes in the composition of osmolytes, and storage and membrane lipids under the action of cold (CS), heat (HS) and osmotic (OS) shocks in the obligate alkaliphilic micromycete Sodiomyces tronii. During adaptation to CS, an increase in the degree of unsaturation of phospholipids was observed while the composition of osmolytes, membrane and storage lipids remained the same. Under HS conditions, a twofold increase in the level of trehalose and an increase in the proportion of phosphatidylethanolamines were observed against the background of a decrease in the proportion of phosphatidic acids. OS was accompanied by a decrease in the amount of membrane lipids, while their ratio remained unchanged, and an increase in the level of polyols (arabitol and mannitol) in the fungal mycelium, which suggests their role for adaptation to OS. Thus, the observed consistency of the composition of membrane lipids suggests that trehalose can participate in adaptation not only to extremely alkaline conditions, but also to other stressors – HS, CS and OS. Taken together, the data obtained indicate the adaptability of the fungus to the action of various stressors, which can point to polyextremotolerance.

State of the art, recent advances, and challenges in the field of fungal mycelium materials: a snapshot of the 2021 Mini Meeting

Material development based on fungal mycelium is a fast-rising field of study as researchers, industry, and society actively search for new sustainable materials to address contemporary material challenges. The compelling potential of fungal mycelium materials is currently being explored in relation to various applications, including construction, packaging, “meatless” meat, and leather-like textiles. Here, we highlight the discussions and outcomes from a recent 1-day conference on the topic of fungal mycelium materials (“Fungal Mycelium Materials Mini Meeting”), where a group of researchers from diverse academic disciplines met to discuss the current state of the art, their visions for the future of the material, and thoughts on the challenges surrounding widescale implementation.

Microbiological activity in the soils of pingos and thermokarst depressions in the south of the Vitim Plateau (Transbaikalia, Eastern Siberia)

The intensity of microbiological processes in soils of pingos and thermokarst depressions in the south of the Vitim Plateau was studied. The number of dominant groups of microorganisms (Fungi; Bacteria, and Actinomycetes as a separate group) in Haplic Chernozems (Stagnic, Turbic) and Calcaric Gleyic Phaeozems were identified. Carbon accumulation in microbial biomass in soils of pingos and thermokarst depressions varies considerably in comparison with background soils. Bacterial microflora has been proven to prevail in soils under the study. The maximum indicators of actinomycete and fungal mycelium were found in the soils of thermokarst depressions. Microbiological activity for all studied parameters is higher in Calcaric Gleyic Phaeozems.

Qualitative and Quantitative Characteristics of Soil Microbiome of Barents Sea Coast, Kola Peninsula

The soil microbiome of the Barents Sea coast of the Kola Peninsula is here characterized for the first time. The content of copies of ribosomal genes of archaea, bacteria, and fungi was determined by real-time PCR. Reserves and structure of biomass of soil microorganisms such as total biomass of fungi and prokaryotes, length and diameter of mycelium of fungi and actinomycetes, proportion of mycelium in biomass, number of spores and prokaryotic cells, proportion of small and large fungal propagules, and morphology of mycobiota spores were determined. The largest number of ribosomal gene copies was found for bacteria (from 6.47 × 109 to 3.02 × 1011 per g soil). The number of copies of ribosomal genes of fungi and archaea varied within 107–109 copies of genes/g soil. The biomass of microorganisms (prokaryotes and fungi in total) varied from 0.023 to 0.840 mg/g soil. The share of mycobiota in the microbial biomass ranged from 90% to 97%. The number of prokaryotes was not large and varied from 1.87 × 108 to 1.40 × 109 cells/g of soil, while the biomass of fungi was very significant and varied from 0.021 to 0.715 mg/g of soil. The length of actinomycete mycelium was small—from 0.77 to 88.18 m/g of soil, as was the length of fungal hyphae—an order of magnitude higher (up to 504.22 m/g of soil). The proportion of fungal mycelium, an active component of fungal biomass, varied from 25% to 89%. Most (from 65% to 100%) of mycobiota propagules were represented by specimens of small sizes, 2–3 microns. Thus, it is shown that, despite the extreme position on the mainland land of Fennoscandia, local soils had a significant number of microorganisms, on which the productivity of ecosystems largely depends.

Pathogenic fungi infection attributes of malarial vectors Anopheles maculipennis and Anopheles superpictus in central Iran

Background Due to the effect of synthetic and commercial insecticides on non-target organisms and the resistance of mosquitoes, non-chemical and environmentally friendly methods have become prevalent in recent years. The present study was to isolate entomopathogenic fungi with toxic effects on mosquitoes in natural larval habitats. Methods Larvae of mosquitoes were collected from Central, Qamsar, Niasar, and Barzok Districts in Kashan County, Central Iran by standard dipping method, from April to late December 2019. Dead larvae, live larvae showing signs of infection, and larvae and pupae with a white coating of fungal mycelium on the outer surface of their bodies were isolated from the rest of the larvae and sterilized with 10% sodium hypochlorite for 2 min, then washed twice with distilled water and transferred to potato-dextrose-agar (PDA) and water-agar (WA) media and incubated at 25 ± 2 °C for 3–4 days. Larvae and fungi were identified morphologically based on identification keys. Results A total of 9789 larvae were collected from urban and rural areas in Kashan County. Thirteen species were identified which were recognized to belong to three genera, including Anopheles (7.89%), Culiseta (17.42%) and Culex (74.69%). A total of 105 larvae, including Anopheles superpictus sensu lato (s.l), Anopheles maculipennis s.l., Culex deserticola, Culex perexiguus, and Culiseta longiareolata were found to be infected by Nattrassia mangiferae, Aspergillus niger, Aspergillus fumigatus, Trichoderma spp., and Penicillium spp. Of these, Penicillium spp. was the most abundant fungus isolated and identified from the larval habitats, while An. superpictus s.l. was the most infected mosquito species. Conclusions Based on the observations and results obtained of the study, isolated fungi had the potential efficacy for pathogenicity on mosquito larvae. It is suggested that their effects on mosquito larvae should be investigated in the laboratory. The most important point, however, is the proper way of exploiting these biocontrol agents to maximize their effect on reducing the population of vector mosquito larvae without any negative effect on non-target organisms.

Biological control of Golovinomyces cichoracearum, the causal pathogen of sunflower powdery mildew

Background Powdery mildew was found in most of the sunflower fields in Egypt, causing severe yellowing of the blade, petiole, stem and calyx, as well as a considerable defoliation during the summer season of 2018. Out of the fungal mycelium from infected leaves, collected from sunflower fields in the four Egyptian Governorates (Kafr El-Sheikh, Gharbia, Giza and El-Beheira), five isolates of powdery mildew pathogen were obtained and identified using morphological and molecular identification methods. Results In 2019 and 2020 seasons, five biocontrol agents (Bacillus subtilis, B. pumilus, Trichoderma harzianum, T. viride and T. koningii) were used to control powdery mildew disease on sunflower plants under field conditions compared with the fungicide (Vectra 10% SC). Treatments were significantly effective for controlling the powdery mildew disease relative to the control. The best treatment for reducing disease parameters (final disease severity (FDS%), area under disease progress curve (AUDPC) and efficacy) than the control was T. koningii. Foliar application of all the tested treatments improved plant height, head and stem diameters and seed yield in relation to untreated plants (control). The components (FDS%, AUDPC and efficacy) were extracted and described approximately 95.251% of the pooled data of seasons 2019 and 2020. In such pooled data, the principal components (PC1, PC2 and PC3) of all disease parameters, plant development parameters and yield components were recorded 76.305, 86.635 and 96.265% of the total variance, respectively. Conclusion A biological control agent, such as T. koningii, can be suggested for disease control based on the experimental findings.

Assessment of the intensity of damage to sunflower caused by artificial infection with septoria in phytotron conditions

The aim of our study was to analyze the development of Septoria leaf spot in sunflower seedlings artificially infected with the mycelium suspension of the pathogen in the phytotron and to determine the degree of damage caused by this disease in the lines of different origins. The materials for the experiment were self-pollinating sunflower lines ZL22A, ZL58A, ZL78A (all of Zaporizhzhya breeding the Institute of Oilseeds Crops of NAAS) and line HAR7 (originating from the USA). The research was conducted in the phytotron facility at the Department of Genetics and Plant Resources of Zaporizhia National University. The seeds of selected sunflower samples were sown into the soil in the specially prepared pots containing drainage and a mixture of chernozem and sand in equal proportions to a depth of 3 cm in two rows of 10 seeds each, with a distance between seeds of 0.5-1 cm. The plants grew and developed on a photoperiod of 16/8 hours (day / night) at a temperature of 23-25oC and a relative humidity of 65%. All samples were watered when needed and received equal amounts of water. Sunflower plants were inoculated in accordance with generally accepted methods of phytopathology. Next, the infected plants were placed in a humid chamber. The plants were infected with the inoculum of a 30-day old mycelium culture of the fungus Septoria helianthi, grown by cultivating the pathogen on a solid nutrient medium. The isolation of pathogen in pure culture as well as preparation of inoculum for infection were carried out using methods which were generally accepted in phytopathology and mycology, supplemented by author's own methodology. The degree of damage to the plants was assessed by visual examination of all leaves, using a 5-point scale, modified for our studies. The affected lines were determined by the percentage of plants with a certain degree of damage. The results of this research showed that sunflower lines sustained varying degrees of damage and, accordingly, varying degrees of resistance to Septoria. The least affected was line HAR7, with 70% of the plants in this line having damaged leaves. The most damaged of those were cotyledons and the first pair of true leaves, whereas just 11.7% of plants had the second pair of true leaves damaged. Completely unaffected plants made up 29.5% of this line. Line ZL22A was affected by 75%. Almost all plants in this line had damaged cotyledons and the first pair of leaves, with 70%. Besides, there were 5% of plants that had all their leaves affected. The number of unaffected plants was 25%. It should be noted that the ZL22A line was close in degree of damage to that of the HAR7 line and showed relative susceptibility to Septoria under phytotron conditions. ZL58A and ZL78A lines were the most affected by Septoria, with 100%. In the ZL58A line, there were 56.2% of plants with damaged cotyledons and the first pair of true leaves, and 43.8% of plants whose second pair of true leaves showed the symptoms of the disease. The plants of the ZL78A line with lesions on the cotyledons and the first pair of true leaves made up 60%, whereas the number of plants with the symptoms of Septoria leaf spot on the second pair amounted to 40%. In general, these two lines were characterized by the same degree of damage and can be considered susceptible to Septoria leaf blight. The disease progression on the HAR7 line is 38.2%, on the ZL22A line is 40%, on the ZL78A line is 60%, on the ZL58A line is 60,9%. The findings show that sunflower plant lines that were artificially infected with an aqueous suspension of fungal mycelium containing Septoria leaf spot pathogen in the conditions of phytotron developed the disease rather rapidly and exhibited varying degrees of damage. The proposed method provides a reliable infection of sunflower samples with the pathogen S. helianthi, a rapid assessment of the intensity of damage to sunflower lines by septoria.