The influence OF Se(IV)- and Se(VI)- modified zeolite on antioxidant and antimicrobial activity of fungi Pleurotus ostreatus and Coriolus versicolor

Poslednjih nekoliko decenija sve veća pažnja se posvećuje nutritivnim i medicinskim svojstvima gljiva. Gljive mogu transformisati biljne lignocelulozne ostatke niske hranljive vrednosti u visoko vredne delikatesne namirnice. Dokazano je i da mogu usvojiti selen, iz supstrata na kojem rastu, i da ta sposobnost zavisi od vrste gljive, kao i od oblika i koncentracije dodatog selena. Selen je esencijalni mikronutrijent, neophodan za normalno funkcionisanje organizma. Istraživanja o zastupljenosti ovog elementa ukazuju da zemljište Srbije, kao i životne namirnice spadaju među selenom najsiromašnije u svetu. Sa druge strane, Srbija raspolaže značajnim količinama zeolita i procenjuje se da se najveće zalihe ovog minerala u Evropi nalaze u blizini Vranjske Banje. Zeolitski tuf može biti modifikovan i potom upotrebljen kao adsorbent selenit- i selenat-jona. Uticaj Se(IV)- i Se(VI)-modifikovanog zeolita (SeIV-CLI i SeVI-CLI) na aktivnost enzima antioksidativnog sistema zaštite praćen je u svežim plodonosnim telima gljiva Pleurotus ostreatus i Coriolus versicolor. Jača aktivnost enzima superoksid-dismutaze i glutation-peroksidaze je utvrđena u svim uzorcima gljive P. ostreatus odgajenim na supstratu sa dodatkom selena u odnosu na kontrolu. Kod većine uzoraka gljive C. versicolor, obogaćene selenom, ustanovljena je jača aktivnost enzima superoksid-dismutaze i katalaze i slabija aktivnost glutation-peroksidaze u poređenju sa kontrolom. Primenom SDS-PAGE gel elektroforeze utvrđeno je da selen prisutan u uzorcima nije uticao na promenu molekulskih masa ispitivanih gljiva. U ovoj disertaciji izolovani su metanolni ekstrakti gljiva P. ostreatus i C. versicolor, odgajenih na supstratu bez i sa dodatkom različitih koncentracija selena u vidu Se(IV)- i Se(VI)-modifikovanog zeolita. Sadržaj selena u ekstraktima pripremljenim iz gljive P. ostreatus, obogaćene ovim elementom, je bio od 35–125 puta veći u poređenju sa kontrolnim ekstraktom, dok je kod gljive C. versicolor određen od 180–250 puta veći sadržaj selena...In recent decades, more attention is paid to the nutritional and medicinal properties of fungi. Fungi can transform lignocellulosic residues of plants with low nutritional value into high-value delicious food. It has been shown that fungi can absorb selenium from the growing substrate and that this ability depends on the type of fungus and concentration of the added selenium. Selenium is an essential micronutient, necessary for the proper functioning of the organism. Research on the distribution of this element indicates that land in Serbia, and foodstuffs are among the poorest in the world. On the other hand, Serbia has significant quantities of zeolite and it is estimated that the largest reserves of this mineral in Europe are located near Vranjska Banja. The zeolitic tuff can be modified and then used as an adsorbent for selenite- and selenate- ions. The influence of Se(IV)- and Se(VI)- modified zeolite (SeVI-CLI and SeVI-CLI) on the enzyme activity of the antioxidant protection system was monitored in fresh fruiting bodies of the fungi P. ostreatus and C. versicolor. Increased activity of the superoxide dismutase and glutathione peroxidase enzymes was measured in all samples of P. ostreatus grown on the substrate with the addition of selenium compared to the control samples. Most samples of C. versicolor enriched with selenium showed increased activity of superoxide dismutase and catalase enzymes and weaker activity of glutathione peroxidase compared to the control. By applying SDS-PAGE gel electrophoresis it was found that selenium present in the samples did not affect the molecular weight change of the tested fungi. In this dissertation methanol extracts of fungi P. ostreatus and C. versicolor grown on a substrate with and without addition of various concentrations of selenium in the form of Se(IV)- and Se(VI)-modified zeolite were isolated..

ASSESSMENT OF SEASONAL AIRBORNE RESISTOME DYNAMICS IN RESPONSE TO AIR POLLUTION EXPOSURE IN THE BELGRADE METRPOLITAN AREA

Antimicrobial resistance (AMR) and air pollution have been identified as one of the most serious threats to human health worldwide. The scarce data demonstrating their interdependence indicates a need to obtain evidence from a broader global area, especially from regions exposed to high air pollution. Considering that Serbia is a country struggling with excessive antibiotics use and misuse, a high percentage of multidrug-resistant bacterial isolates, and poor air quality, the Serbian capital Belgrade has been recognized as an interesting research model for the effects of air pollution on the airborne transmission of AMR. Hence, this abstract aims to present the concept of an ongoing project (AirPollRes) that points to the additional risk dimension of air pollution to human, animal, and environmental health. After optimization of air sampling and DNA extraction protocol, the air samples will be collected at nine locations in the Belgrade metropolitan area selected according to air pollution level during four seasons. The state-of-the-art shotgun metagenomic sequencing and bioinformatic analysis of obtained sequences will provide information about microbial community composition of airborne metagenomes. In addition, sequenced airborne metagenomes will be analyzed for the abundance and diversity of resistomes (antibiotic and biocide/metal resistance genes) and mobilomes using several databases and tools. Correlation analyses will offer us insight into the effect of air pollution and seasonal variations on abundance and diversity of airborne pathogens, resistome and mobilome in the Belgrade metropolitan area. In-depth approach of the AirPollRes project will provide the first insights into intersection of AMR and air pollution in the Belgrade metropolitan area, which is highly vulnerable to these health threats. As the AirPollRes is a pioneering project in this field, the expected shortterm impact is the introduction of routine monitoring of pathogenic microbes and resistance determinants in the air in Belgrade, while the longer-term impact will be reflected in the improvement of human and animal health, allowing for a longer life with higher quality.Book of abstracts and conference proceedings / 3rd International Conference Antimicrobial Resistance - Current State and Perspectives, 16-18. May 2024, Novi Sad, Serbi

The fungistatic activity of organic selenium and its application to the production of cultivated mushrooms agaricus bisporus and pleurotus spp.

The activity of organic selenium against pathogenic molds and its use as a potential selenium source in the production of enriched mushrooms were examined. The effect of commercial selenized yeast on mycelia growth was examined using a method with mycelia disks and a well diffusion method. For mushroom enrichment, different concentrations of selenium were added to a growth substrate. The results presented in this paper suggest that the most suitable concentration of selenized yeast that inhibits the growth of the mycopathogenic molds is 70-100 mg/kg of selenium. With the addition of this concentration to the substrate, mushroom fruit bodies will uptake a high level of selenium, about 100 mu g/g for Pleurotus spp., and 200 mu/g for Agaricus bisporus in dry weight of the mushroom. Thereby a double effect in the cultivation of mushrooms is achieved

MORPHOLOGICAL CHANGES OF STAPHYLOCOCCUS AUREUS AND SALMONELLA ENTERITIDIS UPON EXPOSURE TO THE EXTRACT OBTAINED FROM PLEUROTUS OSTREATUS MUSHROOM

In last decades, bacterial resistance to first choice antibiotics has been drastically increasing, therefore, the research of new antimicrobial substances is of great importance. This rising problem with bacterial resistance to existing antibiotics affects not only the health care institutes but also food plants. S. aureus and S. enteritidis pose a number of challenges to the food industry and cause foodborne illness in humans. In addition, due to their favourable elemental composition, oyster mushrooms (Pleurotus sp.) are a reservoir of bioactive compounds that give them remarkable antibacterial potential. P. ostreatus is of great economic importance and is the second most cultivated edible mushroom, therefore information about its possible targets on bacterial cells is of great importance for use as a dietary supplement or medicinal purposes. The results of the antibacterial assay showed that tested bacterial strains were susceptible to the methanol extract of P. ostreatus (PoME), while microbicidal activity was only detected against Gram-positive bacteria. Scanning electron microscopy (SEM) micrographs suggested that extract acted on cytoplasmic membrane of S. aureus, while the cell envelope of S. Enteritidis was the most likely target. Natural extracts may outperform individual bioactive compounds due to the synergistic interaction between the metabolites, which can enhance the effects of the individual components. Extracts rich in antibacterials are emerging as alternatives to synthetic antibiotics in the food and health sectors. Among these, crude mushroom extracts are particularly sought after for their diverse bioactive ingredients, as they can combat resistant strains of bacteria due to their different targets and modes of action. PoME can be used as an effective antimicrobial agent, suitable for applications aiming to eradicate foodborne pathogens, thus enhancing food safety.Book of abstract: From biotechnology to human and planetary health XIII congress of microbiologists of Serbia with international participation Mikromed regio 5, ums series 24: 4th – 6th april 2024, Mona Plaza hotel, Belgrade, Serbi

The Antibacterial Activity of Coriolus versicolor Methanol Extract and Its Effect on Ultrastructural Changes of Staphylococcus aureus and Salmonella Enteritidis

The antibacterial activity of methanol extract obtained from fruiting body of industrially grown basidiomycete Coriolus versicolor was examined. The Minimum Inhibitory Concentration (MIC) values against various bacteria ranged from 0.625 to 20 mg mL(-1). versicolor expressed bactericidal activity against both Gram-positive and Gram-negative bacteria. The growth curves of Staphylococcus aureus and Salmonella enterica serovar Enteritidis, measured at 630 nm, and confirmed with macrodilution method showed that the obtained extract could inhibit the growth of tested bacteria. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the loss of 260-nm-absorbing material were used to examine the ultrastructural changes in bacteria induced by the extract. When S. aureus was exposed to the MIC of C. versicolor, elongated and malformed cells were observed by SEM, while S. Enteritidis treated cells appeared shorter and aggregated with ruptured cell walls. TEM revealed the formation of non-membrane-enclosed bodies and depleted inner content of S. aureus. Larger and irregular periplasmic space and deformed and scattered components of the cell envelope were observed in treated S. Enteritidis. The loss of 260-nm-absorbing material indicated that the disruptive action of the extract on cytoplasmic membrane was more pronounced in S. aureus than in S. Enteritidis treated cells. The UV and FTIR spectrophotometric analyses revealed diverse composition of C. versicolor extract and high content of total phenolics. Altogether, mushroom extracts could be used to develop nutraceuticals or drugs effective against pathogenic microorganisms

Stimulacija zemljišne mikrobiološke aktivnosti sa klinoptilolitom - uticaj na rast biljke

Zeolites can mitigate ammonium losses to the environment by taking up the ions from sources such as farmyard manure and ammonium-bearing fertilizers. This ability can improve nitrogen fertilizing practice given that ammonium ions loaded onto zeolite are available for plant uptake. The main goal of this study was to assess the influence of zeolite (clinoptilolite) and ammonia-loaded clinoptilolite on growth and yield of red clover (Trifolium pratense L.), as well as their influence on the microbial dynamics in soil. Plants sown in pots were cut four times, and dry matter yield (DM) of each harvest was weighed. The number of culturable bacteria, moulds, ammonifiers, Azotobacter sp. and actinomycetes was determined at the beginning of the experiment, and after each harvest. Two control treatments (soil without fertilizer and soil supplemented with mineral fertilizer - CAN) were included in the study. The application of ammonia-loaded clinoptilolite positively and significantly affected the microbial activity and provided higher yields (from 4.9 g/pot in ammonia-loaded clinoptilolite treatment to 4.3 g/pot in soil with zeolite treatment). Our results suggest that the addition of clinoptilolite to organic fertilizers (manure, composts) could be recommended. The increase of microbial communities’ abundances and their activity represented the key benefit from clinoptilolite application.Zeoliti mogu ublažiti otpuštanje amonijaka u prirodu preko uzimanja jona iz izvora kao što su stajnjak i đubriva bogata amonijakom. Ova sposobnost može unaprediti đubrenje azotom preko zeolitom usvojenih amonijum jona koji bi tako postali dostupni za usvajanje biljkama. Cilj ovih ispitivanja je bio procena uticaja zeolita (klinoptilolita) i zeolita obogaćenog amonijakom na rast i prinos crvene deteline (Trifolium pratense L.), kao i na njihovu ulogu u mikrobiološkoj dinamici zemljišta. Biljke sejane u sudovima su košene četiri puta i meren je prinos suve materije (SM) svakog otkosa. Broj bakterija, plesni, amonifikatora, Azotobacter sp. i aktinomiceta je utvrđen na početku ogleda i nakon svakog košenja. U istraživanja su uključena dva kontrolna tretmana (zemljište bez đubriva i zemljište sa dodatim mineralnim đubrivom - KAN). Primena klinoptilolita obogaćenog sa amonijakom je pozitivno i značajno uticala na mikrobiološku aktivnost i povećala je prinos (od 4,9 g po sudu kod tretmana sa klinoptilolitom obogaćenim amonijakom do 4,3 g po sudu u zemljištu sa zemljištem i zeolitom zajedno). Naša istraživanja sugerišu da se može preporučiti dodavanje klinoptilolita organskim đubrivima (stajnjaku, kompostu). Ključna dobit od primene klinoptilolita bi se ogledala u povećanju zastupljenosti mikrobioloških zajednica i njihove aktivnosti

Synthesis and antimicrobial properties of Zn-mineralized alginate nanocomposites

New bioactive and antimicrobial biomaterials were produced by alginate-mediated biomineralization with Zn-mineral phase. The synthesis procedure is simple, cost-effective and resulted in. two different Zn-mineralized alginate nanocomposites, Zn-carbonate/Zn-alginate and Zn-phosphate/Zn-alginate. The presence of Zn-mineral phase and its type, have significantly affected nanocomposite morphology, stability, total metallic loading and potential to release Zn(II) in physiological environment. Antimicrobial experiments showed that both types of Zn-mineralized nanocomposites exhibit strong antimicrobial effect against Escherichia coli, Staphylococcus aureus and Candida albicans. These results suggest that alginate biomineralization, where minerals are salts of essential metallic ions like Zn(II), represents a'good strategy for designing multifunctional biomaterials for potential biomedical applications.This is the peer reviewed version of the paper: Malagurski, I., Levic, S., Pantic, M., Matijasevic, D., Mitric, M., Pavlovic, V., & Dimitrijevic-Brankovic, S. (2017). Synthesis and antimicrobial properties of Zn-mineralized alginate nanocomposites. Carbohydrate Polymers, 165, 313–321. [https://doi.org/10.1016/j.carbpol.2017.02.064

Biološki potencijal odabranih vrsta makromiceta obogaćenih selenom

: Industrijski gajene gljive imaju veoma izraženu nutritivnu vrednost i predstavljaju bogat izvor esencijalnih aminokiselina, vitamina, mineralnih materija, ugljenih hidrata, proteina kao i važnih sekundarnih metabolita. Tokom višegodišnjih istraživanja dokazano je da gljiva može uspešno usvojiti selen iz čvrstog supstrata ili tečne podloge u koncentraciji koja može da zadovolji dnevne potrebe čoveka. Kapacitet usvojivosti selena zavisi od vrste gljive, hranljive podloge, ekoloških parametara kao i od oblika i koncentraciјe u kom јe selen dodat u podlogu. Kako gljive sadrže brojne bioaktivne komponente u vidu primarnih i sekundarnih metabolita, dodatno selenom obogaćene pečurke moguće јe koristiti u svežem i sušenom stanju ili kao potencijalni dijetetski suplement. Ispitana je biološka aktivnost selenom obogaćenih gljiva Coriolus versicolor i Pleurotus ostreatus. Kao izvori selena upotrebljena su organska jedinjenja u obliku selenskog kvasca i selenouree, kao i Se(IV)- i Se(VI)-modifikovani zeoliti

MEDICINAL MUSHROOM EXTRACTS ATTENUATE PSEUDOMONAS AERUGINOSA QUORUM SENSING AND VIRULENCE

Pseudomonas aeruginosa has been recognized as a priority pathogen by World Health Organization, due to the emergence of multidrug-resistant (MDR) strains. Thus, new treatment options such as antivirulence strategy is urgently needed. This strategy is based on the disruption of quorum sensing (QS) activity of this pathogen. The focus of this research was to explore the anti-QS activity of four selected medicinal mushrooms (Lentinula edodes, Cantharellus cibarius, Trametes versicolor and Pleurotus ostreatus) extracts on MDR clinical isolate P. aeruginosa MMA83. Another aim was to check their cytotoxicity on Caenorhabditis elegans AU37 (glp-4(bn2) I; sec-1(km4). Among three types of mushroom extracts - hot water polysaccharide extracts (WPE), hot alkali polysaccharide extracts (APE) and methanol extracts (Met), APE extracts downregulated all tested QS and virulence factors genes of P. aeruginosa MMA83. The most prominent effect was observed for C. cibarius APE extract, lowering expression from 2-fold (for lasI gene) to 20-fold for lasB gene. Extracts didn’t show cytotoxic effect on C. elegans. The efficacy of APE extracts in lowering the expression of QS and virulence factors genes of P. aeruginosa MMA83 indicate that these extracts can reduce pathogenicity of P. aeruginosa. Also, they possess one of the desirable biotechnology features – the absence of cytotoxicity. Anti-QS and antivirulence effect of APE extracts on P. aeruginosa envisages these extracts as the promising therapeutic candidates for the development of next-generation antivirulence agents.Book of abstract: From biotechnology to human and planetary health XIII congress of microbiologists of Serbia with international participation Mikromed regio 5, ums series 24: 4th – 6th april 2024, Mona Plaza hotel, Belgrade, Serbi

Antibakterijska aktivnost metanolnog ekstrakta gljive Coriolus versicolor obogaćene organskim i neorganskim izvorom selena.

Coriolus versicolor je medicinska gljiva čija je lekovitost potvrđena brojnim istraživanjima. Biološki aktivni polisaharidi i polisaharopeptidi izolovani iz micelije submerzno gajene Coriolus versicolor gljive se koriste u prevenciji mnogih bolesti. Ova gljiva se može gajiti i na čvrstom supstratu, na otpadu iz poljoprivrede i na taj način se može uspešno upotrebiti pri bioremedijaciji. Cilj ovog istraživanja je bio da se utvrdi da li se antibakterijska aktivnost metanolnog ekstrakta gljive Coriolus versicolor gajenjem na čvrstom supstratu obogaćenom selenom može povećati. Kao supstrat za gajenje upotrebljena je mešavina slame, hrastove pljevine i pšeničnih mekinja. Za obogaćivanje supstrata korišćeni su organski i neogranski izvori selena: selesnki kvasac (Sel-Plex® , Alltech Inc., Lexington, USA) i natrijum selenit, Na2SeO3 u koncentraciji od 25 mg/kg suvog supstrata. Kontrolni uzorak je pripremljen bez dodavanja selena. Nakon metanolne ekstrakcije, određen je sadržaj selena u digestovanim uzorcima upotrebom ICP-OES uređaja. Kod uzorka obogaćenih selenom iz neorganske soli sadržaj selena je bio 123,4 µg/g, a kod uzoraka obogaćenih selenom iz selenskog kvasca 62,4 µg/g suve mase uzorka. Mikrodilucionom metodom ispitana je antimikrobna aktivnost dobijenih metanolnih ekstrakata na 15 sojeva bakterija i utvrđeno je da dodatak neorganske soli dovodi do povećanja antimikrobne aktivnosti u odnosu na kontrolni uzorak samo kod dve Gram-pozitivne bakterije: Bacillus spizizeni ATCC 6633 gde je MIC<0,3125 mg/ml i Enerococcus faecalis ATCC 29212, MIC=40 mg/ml. Sa druge stane, ispitivanjem antimikrobnog delovanja ekstrakata dobijenih iz gljive obogaćene selenom iz kvasca primećeno je izraženije mikrobistatično i mikrobicidno delovanje u poređenju i sa kontrolnim uzorkom i sa uzorkom kome je dodat Na2SeO3 kod skoro svih testiranih Gram-pozitivnih i Gramnegativnih bakterija. Iako dobijeni rezultati ukazuju na to da je u ekstraktu gljive koja je rasla na supstratu sa selenskim kvascem detektovano duplo manje ukupnog selena nego kod uzorka obogaćenog selenitom, antimikrobna aktivnost takvih uzoraka je bila znatno izraženija. Pretpostavlja se da je selen iz organskog izvora promenio hemijski sastav gljive