The Dynamics of Mycobiota Development in Various Types of Wood Dust Depending on the Dust Storage Conditions

Solid or processed wood, and wood waste in particular (dust, shavings, etc.) are the source of a number of health hazards for workers in the wood industry. One of the many negative health effects of exposure to fungi is allergic diseases caused by hypersensitivity reactions. The aim of this study was to investigate the effect of wood species and the degree of dust fragmentation, resulting from processing conditions and storage conditions on the level of wood dust contamination with microscopic fungi during 1 year of storage. An additional aspect of the research was the assessment of the influence of the antioxidant wood bioactive compounds on the development of A. alternata microscopic fungi. It was found that the conditions in which wood dust is stored significantly affect the development of microscopic fungi, especially fungi of the genus Alternaria. The results indicate that temperature is the determining factor, not the relative humidity of the air. The degree of dust fragmentation resulting from the sanding paper grit also has a significant impact on the development of microscopic fungi. Finer dust is more susceptible to the development of microscopic fungi. The antioxidant activity of the wood from which the dust was formed was found to have a significant impact on the development of microscopic fungi. An inverse relationship was observed, indicating the strong activity of antimicrobial substances. Gaining comprehensive knowledge of how all factors affect each other is a key step in understanding the risk and implementing measures to prevent and protect the work environment.

Fungal Endophytes of Vitis vinifera—Plant Growth Promotion Factors

Endophytes are microorganisms that live asymptomatically inside plant tissues. They are beneficial to their host in many aspects, especially as a defense against foreign phytopathogens through the production of a variety of metabolites. These substances can serve as sources of new natural products for medicinal, agricultural, and industrial purposes. This article is focused on endophytic fungi from Vitis vinifera. The purpose of the research was their isolation and identification during the Vitis vinifera growing season. Subsequently, the isolates were tested for the production of biotechnologically interesting metabolites (siderophores, antioxidants, and antifungal compounds). In total, 24 endophytic fungi were isolated, the most represented genus was Cladosporium sp. The results of the test for antioxidant and antifungal properties, as well as siderophore production, have shown that the population of Vitis vinifera endophytic microscopic fungi could serve as a promising source of metabolites with a wide range of applications.

Research of corrosion fracture of D16t and AMg6 aluminum alloys exposed to microscopic fungi

This paper presents an experimental study of biocorrosion of D16T and AMg6 aluminum alloys. The determining role of reactive oxygen species in aluminum biocorrosion by a consortium of molds has been shown. A model is proposed, according to which the initiators of corrosion damage to the metal surface are superoxide anion radical and hydrogen peroxide released during the life of micromycetes. It is assumed that the initiation and development of biocorrosion occurs, among other things, as a result of the process of reductive activation of oxygen and the Fenton decomposition of hydrogen peroxide. A conclusion is made about the mechanism of the occurrence of intergranular and pitting corrosion of aluminum alloys interacting with microscopic fungi.

TAXONOMIC COMPOSITION OF FUNGI COMMUNITIES IN THE RHIZOSPHERE OF FABA BEANS

The taxonomic composition of rhizosphere complexes of microscopic fungi was determined under nine varieties of faba beans grown in small-plot experiments on black soil with a pH of 7.6, ob-serving zonal agricultural techniques (Belgorod, Russia). It was revealed that under different vari-eties of faba beans the list of micromycete species is not the same, but their number is lower than in control soil. The number of micromycete propagules in the rhizosphere of beans (34 ± 1.7 thou-sand CFU / g soil) is on average 2 times higher than in the control soil (17 ± 1.2 thousand CFU / g soil). The greatest species diversity was found in the varieties Velena and Akvadul (18 and 16 species, respectively). The mycocomplexes of the Tsarskiy Yield and Leader varieties were dis-tinguished by the greatest similarity with the control. Phytopathogenic fungi Fusarium oxysporum dominated in the rhizosphere complexes of all studied varieties of vegetable beans, and the spe-cies A. fabaе, C. herbarum, and U. botrytis were present only in the rank of random species in my-cocomplexes under some varieties.

Copper oxalate formation by lichens and fungi

The present work focuses on the revealing the patterns of copper oxalates formation under the influence of lichens and fungi by combination of the results of field studies and model experiments. These findings create the scientific basis for the potential microbial technology applications (ore enrichment, monuments conservation, environment bioremediation, etc.). Copper oxalate moolooite Cu(C2O4)·H2O was discovered in saxicolous lichen Lecidea inops on the weathered chalcopyrite ore of Voronov Bor deposit (Central Karelia, Russia). Bioinspired syntheses of moolooite and wheatleyite Na2Cu(C2O4)2 2H2O with the participation of the microscopic fungi Aspergillus niger (active producer of oxalic acid) were carried out on weathered Cu-ore from the Voronov Bor deposit. It was shown that morphology of moolooite crystals is controlled both by the underlying rock and by the species composition of microorganisms. Iron ions (sourced from the underlying rock) in the crystallization medium inhibits the moolooite formation. The observed intensive dissolution of moolooite crystals are well explained by washing effect of the intratalline solutions which depends on repeatedly dehydration / rehydration cycles in the lichens. Joint interpretation of original and published data shows that moolooite along with other cooper oxalates are biominerals.

Effect of Air Purifier Use in the Classrooms on Indoor Air Quality—Case Study

Dissatisfaction with indoor air quality is common even in relatively new or renovated Polish school buildings. To improve air quality in educational buildings, portable devices have seen increased use, for which manufacturers guarantee a high level of indoor air purification. However, their optimized operation largely depends on their correct use. The aim of this article was to determine the effectiveness of air purification in a primary school using an air purification device with an analysis of the classroom indoor air quality (IAQ). Two criteria were used, microbiological and particulate matter concentration. Measurements were made before device installation and during its continuous operation, and before and after lessons on chosen days. Measurements related to IAQ did not detect clear differences in the analyzed measurement periods. For microbiological contamination, in the morning before lessons, the total count for all bacteria and microscopic fungi was definitely lower than after lessons. Comparing the periods before and after device installation, no clear tendency for reducing the bacteria count or microscopic fungi occurred during air purifier operation, nor was there any noticeable trend in the reduction of particulate matter. There was no improvement in air quality in the classrooms during the operation of the purification devices.

Antimicrobial peptides as promising drugs for treatment of primary viral pneumonia

The COVID-19 pandemic which began in March 2020 has again drawn attention to the problem of treating primary viral pneumonia (PVP), wherein damage to the tissues of the lower respiratory tract including functionally important alveolocytes occurs as a result of cell infection by pathogens of the Virae Kingdom. Whereas treatment of bacterial pneumonia is based on the basic approach related to the use of antibiotics (which effectiveness needs to be verified more often than ever due to the “curse of the resistance effect” — that, however, does not cancel the essence of the basic approach), efficient PVP treatment is feasible only in case of available etiotropic, but catastrophically few, drugs. Such drugs in case of the influenza A virus (Articulavirales: Orthomyxoviridae, Alphainfluenzavirus) have been known since the second part of the XXth century. However, no consensus was achieved among clinicians regarding particularly dangerous human coronaviruses (Nidovirales: Coronaviridae, Betacoronavirus) which threat has driven the world epidemiology in the XXIst century: SARS-CoV (subgenus Sarbecovirus), MERS-CoV (Merbecovirus), SARS-CoV-2 (Sarbecovirus). And we should be prepared to the fact that increase in population density and scaling up of anthropogenic impact on ecosystems elevates a probability of overcoming interspecies barriers by natural focal viruses and their penetration into the human population with adverse epidemic consequences. Therefore, PVP therapy should be developed systematically in the nearest future. Antimicrobial peptides (AMP) as the components of non-specific innate immunity against a wide range of infectious pathogens: bacteria (Bacteria), microscopic fungi (Fungi) and viruses (Virae) may serve as a platform for developing such system. Our review justifies a way to select such platform and provides well-known examples of successfully used AMP in treatment of PVP and related pathological conditions.

Microbial Degradation of Plastics and Approaches to Make it More Efficient

Abstract— The growing worldwide production of synthetic plastics leads to increased amounts of plastic pollution. Even though microbial degradation of plastics is known to be a very slow process, this capacity has been found in many bacteria, including invertebrate symbionts, and microscopic fungi. Research in this field has been mostly focused on microbial degradation of polyethylene, polystyrene, and polyethylene terephthalate (PET). Quite an arsenal of different methods is available today for detecting processes of plastic degradation and measuring their rates. Given the lack of generally accepted protocols, it is difficult to compare results presented by different authors. PET degradation by recombinant hydrolases from thermophilic actinobacteria happens to be the most efficient among the currently known plastic degradation processes. Various approaches to accelerating microbial plastic degradation are also discussed.

Fouling communities of microscopic fungi on various substrates of the Black Sea

Fungi are the most active biodeteriorators of natural and man-made materials. The article presents generalizations of the studies (2001–2019) of communities of microscopic fungi within biofilms on various substrates: shells of live Mytilus (Mytilus galloprovincialis, 670 specimens) and Ostreidae (Crassostrea gigas, 90 specimens), fragments of driftwood (over 7,000), stones (40), concrete of hydrotechnical constructions along the shoreline (80) and wood between concrete blocks in constructions on the shores (80). The studies were carried out in Odessa Oblast, the coastal zone of Sevastopol and open area of the Black Sea. There were identified 123 species of micromycetes, belonging to 65 genera, 33 families, 21 orders, 10 classes, 4 divisions, 2 kingdoms: Fungi and Chromista (fungi-like organisms). The Chromista kingdom was represented by 1 species – Ostracoblabe implexa, on shells of C. gigas. The number of species of micromycetes on various substrates varied 23 (wood between concrete blocks of hydrotechnical constructions) to 74 (shells of M. galloprovincialis at the depths of 3 and 6 m). On all the substrates, the following species were found; Alternaria alternata, Botryotrichum murorum. The communities were found to contain pathogenic fungi Aspergillus fumigatus (shells of mollusks, stones, concrete), A. terreus (concrete), Fusarium oxysporum, Pseudallescheria boydii (shells of mollusks). The best representation was seen for the Pleosporales order – from 12.9% (shells of M. galloprovincialis, 0.3 m depth) to 33.3% (shells of C. gigas) of the species composition. Toxin-producing species of Microascales in mycological communities accounted for 1.6% (driftwood) to 40.0% (concrete), and were also observed on shells of Bivalvia – 11.1–32.3%. Similarity of species composition of mycological communities according to Bray-Curtis coefficient varied 21.1% (driftwood and concrete, 10 shared species) to 72.7% (shells of M. galloprovincialis, the depths of 3 and 7 m and shells of C. gigas, 45 shared species). Using graphs of indices of mean taxonomic distinctness (AvTD, Δ+) and variation (Variation in Taxonomic Distinctness index, VarTD, Λ+), we determined deviations of taxonomic structure of the studied mycological communities from the level of mean expected values, calculated based on the list of species, taking into account their systematic positions. The lowest values of index Δ+ were determined for communities on shells of M. galloprovincialis, 0.3 m depth, driftwood, stones and concrete. These communities had uneven distribution of species according to higher taxonomic ranks and minimum number of the highest taxa: 4–6 classes, 1–2 divisions, Fungi kingdom. Disproportion in species composition with decrease in the number of the highest taxa occurred in extreme environmental conditions. Using index Λ+, we found that the most complex taxonomic structure of fungi communities has developed on concrete and shells of C. gigas. In mycological communities on those substrates, the number of species was low (25 and 46), but they belonged to 4–7 classes, 2–3 divisions, 1–2 kingdoms. To compare the structures of mycological communities that have developed in such substrates in biotopes sea, sea-land-air, land-air, we compiled a list of fungi based on the literature data, which, taking into account our data, comprised 445 species of 240 genera, 103 families, 51 orders, 15 classes, 5 divisions, 2 kingdoms. The analysis revealed that on substrates with similar chemical composition, in all the biotopes, the species of the same divisions dominated (genus and family may vary). Therefore, in the biotope land-air – Hypocreales, Pleosporales, Eurotiales (genera Acremonium, Fusarium, Alternaria, Aspergillus, Penicillium); sea – Pleosporales, Eurotiales, Microascales (Alternaria, Aspergillus, Penicillium, Corollospora); sea-land-air – Pleosporales, Microascales (Alternaria, Leptosphaeria, Aspergillus, Penicillium, Corollospora, Halosarpheia). Monitoring of species composition of myxomycetes is needed in farms that cultivate industrial objects, recreation sites, various buildings for prevention of mycotoxin intoxication and infestation by mycodermatoses and other diseases caused by opportunistic and pathogenic fungi.

Influence of feeds contaminated by microscopic fungi on the physiological state of animals

Today feeding disorders (deficiency of crude protein and limiting amino acids), the use of feed contaminated with microscopic fungi can lead to immune depression. When feeding dysfunctional feed, the live weight gain of young animals and fattening pigs is reduced by 10-90%, depending on the balance and completeness of the rations in terms of nutrients. The article assesses the degree of contamination of feed with microscopic fungi and studies the effect of eliminating the deficiency of crude protein, lysine and methionine on the health status and weight gain of laboratory rats when feeding moldy wheat grain. A balanced for essential amino acids feed allows reducing the stress of the body's defense system from the negative effects of saprophytes. An experiment was carried out on 200 (10 groups, n = 20) weaned rats of the Wistar line in order to comparatively study the consequences of feeding the diets containing wheat grain contaminated with fungi of the genera Aspergillus and Penicillium, deficient and balanced to the norms of the requirement for crude protein and two essential amino acids - lysine and methionine. The number of micromycete reaches 109 CFU (spores) in 1 gram of feed. These molds are dangerous because of the possibility of their spores entering the body of animals and germinating in the lungs, liver, kidneys, heart, intestines, reproductive organs, and muscle tissue. Once in the blood, mold spores spread throughout the body. A complete zootechnical analysis of grain was carried out in the toxicology laboratory using the methods of zootechnical and biochemical analyzes of feed, livestock products and metabolic products. The negative effect of microscopic fungi on the health indicators of white rats is less pronounced with a balanced diet for essential amino acids. A decrease in the tension of immunity, expressed in a decrease in T-cell deficiency and activation of phagocytosis, was determined. The average daily gain on the contaminated feed decreased by no more than 20%, while the gain on the contaminated diet was 50-60% lower.