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Nanostructured Sr-Doped Hydroxyapatite: A Material with Antimicrobial Potential
No full textThis research investigated the feasibility of producing strontium-doped nanocrystalline hydroxyapatite (SrHAp) through an environmentally benign synthesis approach and evaluated the antimicrobial activity of the resulting material. The synthesized nanomaterial was subjected to comprehensive characterization. The antimicrobial efficacy of SrHAp was tested against Gram-positive and Gram-negative bacterial strains. X-ray diffraction (XRD) analysis in combination with Fourier-transform infrared (FT-IR) spectroscopy confirmed the successful formation of pure monocrystalline SrHAp. The scanning electron microscopy (SEM) examination revealed two predominant morphological structures: nanorods and prismatic configurations of the SrHAp. Transmission electron microscopy (TEM) demonstrated that the rod-like SrHAp nanocrystals aggregate into elongated grain structures with a size of about 25 nm × 10 nm. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) analysis confirmed the presence and quantification of the concentrations of calcium, strontium, and phosphorus, while confirming the expected calcium–phosphorus ratio characteristic of hydroxyapatite. The study established that the positive surface charge of the material, with a point of zero charge near pH 10, is essential for its antimicrobial efficiency. These results suggest that SrHAp nanomaterials hold promise for biomedical applications, particularly as antimicrobial coatings for implants and scaffolds for bone tissue, where the prevention of infection is critical. Overall, despite its selective and material quantity-dependent antimicrobial efficacy, environmentally friendly synthesized SrHAp can be successfully applied as an effective controller of targeted microbial contamination, especially of Gram-positive bacterial species S. aureus, L. monocytogenes, S. Enteritidis, and A. baumanii
Effects of Conservation Tillage and Nitrogen Management on Yield, Grain Quality, and Weed Infestation in Winter Wheat
No full textChoosing appropriate tillage methods and nitrogen application are important steps in the management of wheat production for obtaining high-yield and high-quality products, as well as managing the level of weed infestation. The aim of this research was to examine the impacts of three different tillage practices (conventional tillage—CT, mulch tillage—MT, and no tillage—NT), and two top dressing fertilization nitrogen levels (rational—60 kg ha−1 and high—120 kg ha−1) on the grain yield and quality of winter wheat, as well as on weed infestation. The present study was carried out in field experiments on chernozem luvic type soil at the Faculty of Agriculture Belgrade-Zemun Experimental field trial “Radmilovac”, in the growing seasons of 2020/2021–2022/2023. The C/N ratio in the soil was also assessed on all plots. The results showed that the number of weeds and their fresh and air-dry weights were higher on the MT and NT plots, compared to the CT plots. Therefore, the CT system has better effects on the yield (5.91 and 5.36 t ha−1) and the protein content (13.3 and 13.1%). Furthermore, the grain weight per spike and the 1000-grain weight were higher in the wheat from the CT system (41.83 and 42.75 g) than from the MT (40.34 and 41.49 g) and NT (40.26 and 41.08 g) systems. Also, the crops from the CT system had higher values of grain density and grain uniformity compared to the crop from the MT and NT systems. Fertilization with a high nitrogen level (120 kg ha−1) causes higher grain yield and more weediness compared with the rational level (60 kg ha−1). Top dressing fertilization in each tillage system resulted in an increase in the number of weeds, but, at the same time, it also resulted in stronger competitive ability of the wheat crop against weeds. The most favorable C/N ratio occurred on the NT plots, and the least beneficial one on the CT ones. A correlation analysis showed strong negative correlations of number (r = −0.82) and fresh weed mass (r = −0.72) with yield. It is concluded that the conventional tillage practice with a low nitrogen dose manifests its superior performance in minimizing weed infestation and maximizing crop productivity
Inhibition of Pseudomonas aeruginosa quorum sensing-regulated behaviors by mushroom extracts
No full textEthnopharmacological relevanceMicrobial biofilm formation, a quorum sensing (QS) phenomenon based on cell-to-cell communication through ligand-receptor interactions, is one of the major causes of nosocomial and chronic infections, foodborne diseases and associated deaths. Its inhibition is therefore considered a promising approach to fight infections. In this context, Cantharellus cibarius, Trametes versicolor, Lentinula edodes and Pleurotus ostreatus, ethno-medicinal and culinary mushrooms, have been investigated as an antibiofilm and anti-QS agents against Pseudomonas aeruginosa.Aim of the studyThe aim of this study was to identify the most effective solvent system for the extraction of bioactive compounds from medicinal mushrooms with antivirulence activity against P. aeruginosa and to elucidate the potential molecular mechanism. In addition, this work aims to address the urgent need for novel, non-antibiotic strategies to combat multidrug-resistant (MDR) pathogens.Materials and methodsFluorescence microscopy (FM), scanning electron microscopy (SEM) and quantitative real-time PCR were employed to explore the antibiofilm and anti-QS potential of mushroom extracts. Chemical characterization of the extracts was performed using Uv–Vis, FTIR and UHPLC Q-ToF MS, while their toxicity was evaluated in an in vivo model using Caenorhabditis elegans.ResultsHot alkali polysaccharide extracts (APE) were the most effective, as they significantly decreased the mRNA levels of all tested QS, especially genes encoding autoinducer synthases (lasI, rhlI and pqsA), by 2- to 17-fold, as well as virulence factor genes of P. aeruginosa. Furthermore, micrographs (FM and SEM) confirmed that all APEs significantly inhibited adhesion and biofilm formation. FTIR and UV–Vis analyses showed that the extracts consisted mainly of polysaccharides, while UHPLC Q-ToF MS analysis revealed the presence of azelaic acid and vanillylacetone in all extracts. The in silico studies showed that vanillylacetone strongly interferes with various QS receptors (LasR, PqsR and RhlR) and could serve as a competitive inhibitor for the autoinducer molecules and possibly induce conformational changes in proteins. APE has also been found to increase the antibacterial efficacy of antibiotics. In vivo toxicity assays with C. elegans demonstrated their safety (with a survival rate of ≥90 %).ConclusionsThe tested mushrooms are promising sources of safe, natural antibiofilm and antivirulence agents, justifying their traditional use in infection control and offering potential for novel anti-infective therapies
The role of perennial grasses in sustainable development
No full textIn recent years, second-generation perennial energy grasses have gained attention for their potential role in reducing greenhouse gas emissions. However, the possible health risks associated with their large-scale cultivation remain insufficiently addressed. This paper presents a narrative literature review of the potential allergenic effects of the main perennial grass energy crops (Phalaris arundinacea, Phragmites australis, Miscanthus × giganteus, Arundo donax), with Zea mays used as a reference first-generation energy crop. A structured search was conducted in major electronic databases using predefined keywords related to bioenergy crops, pollen dispersal, and allergenicity. The search identified a wide body of literature on crop biology and bioenergy potential, but only a limited number of studies addressed allergenic outcomes directly. The evidence suggests that, except for P. arundinacea, most second-generation grasses are late-flowering species. If cultivated on a larger scale near urban centers, these crops could alter the seasonal pattern of allergenic pollen exposure by shifting the allergic burden toward the late growing season (August-October). While the expected overall impact on the annual pollen load appears modest-potentially reducing the June peak typical for Europe while slightly increasing exposure later in the season-these changes warrant consideration in land-use and public health planning
Еconomic aspects of digital technologies in agricultural production
No full textDigitalization in agriculture is an increasingly important phenomenon, involving broad range of activities not only in agricultural production, but also in decision making (management) process at farm level, new approaches to financing of farm activities, etc. Nevertheless, growing importance of digital technologies in agricultural production is not followed by sufficient research on its economic aspects, costs related to their application as well as economic efficiency of investments in this field. Therefore, managers of family farms and agricultural enterprises do not have appropriate insight in real economic consequences (but also social, environmental and political implications) of their deeper involvement in production based on information technologies. The goal of this research is to discuss economic aspects of various ways of using digital technologies in agricultural production
Possibilities for Controlling the Most Important Diseases and Pests of Sour Cherries and an Analysis of Pesticide Residues in Fruits
No full textThis study investigated various protection programs to control the European cherry fruit fly, cherry brown rot, and cherry leaf spot on sour cherries. The effects of acet-amiprid, spinetoram, dodine, boscalid, and pyraclostrobin, applied alone and in com-bination with sucrose, were determined using standard EPPO methods. Pesticide res-idues in the cherry fruit were analyzed using liquid chromatography coupled with mass spectrometry. The highest efficacy in controlling the European cherry fruit fly was achieved by applying acetamiprid twice and spinetoram three times during fruit ripening. Successful protection against brown rot was achieved with a single applica-tion of boscalid and pyraclostrobin with the addition of sucrose. Dodine in combina-tion with boscalid and pyraclostrobin showed good efficacy in controlling cherry leaf spot, which increased with the addition of sucrose. Residues of spinetoram, boscalid, and pyraclostrobin were below the limit of quantification, while only acetamiprid and dodine residues were detected in the fruit samples, but these were well below the maximum residue levels. This study demonstrates that several alternative protection programs can successfully protect cherries against the European cherry fruit fly and diseases during the critical stage of fruit ripening, with residue levels below the pre-scribed maximum levels
Sunflower husk: from waste material to a useful resource.
No full textSunflower (Helianthus annuus L.) is one of the most important
oilseed crops, widely used in industry, agriculture, and as a food source, while
its by-products, such as husks, can be utilized in various ways. Sunflower
husks, constituting up to 40% of the seed's mass, are rich in fiber,
polysaccharides, and other valuable components, with applications in livestock
production, the energy industry, and agriculture. This paper explores different
possibilities for utilizing sunflower husks, with a particular focus on ecological
and energy applications, as well as opportunities for further use in industry and
agriculture. Due to their composition, sunflower husks are used as fuel (in
pellets or as biomass for combustion) and in the production of bio-briquettes.
Moreover, ash obtained from the combustion of sunflower husks contains
valuable nutrients such as phosphorus, potassium, calcium, magnesium, and
trace elements (zinc, copper, manganese, iron), which makes it beneficial for
soil fertilization. The efficiency of ash usage has been improved through
granulation, enabling better application in agriculture. As sunflower production
residues serve as a renewable energy source, sunflower husks represent a
significant resource in the context of sustainable development and energy
efficiency
Mineral Matter of Biomass and Heavy Metals
No full textThe mineral matter of biomass consists of metal quantities found in biomass during the growing
season, in the form of inorganic and organic salts, complex compounds, or existing as ions. The
presence of alkaline and earth alkaline metals, silicon, and other metals varies. The aim of this
paper was to highlight that the determination of the mineral matter (ash) content in biomass
obtained through combustion is one of the key analytical parameters for assessing the class of
biofuel that could be derived from a specific biomass. The mineral matter content in plants is
influenced by various factors, the most important of which are: plant species, plantation age,
climatic conditions, soil characteristics, and the application of agronomic measures. The use of
intensive agronomic practices in modern agricultural production, the proximity of industrial
plants, thermal power plants, mines, and transportation routes inevitably leads to soil and plant
contamination with heavy metals. Exceeding heavy metal content in soils leads to phytotoxicity.
To date, 53 elements have been classified as heavy metals. The concentration of heavy metals,
particularly Cd and Zn, should be limited in ash, especially from an ecological perspective.
Agricultural biomass shows much lower concentrations of heavy metals compared to woody
biomass, which can be explained by the shorter growing period as well as the higher pH value of
agricultural land compared to forest land. For ecological reasons, the content of heavy metals in
pellets and briquettes must be strictly controlled if the ash from biofuels is planned to be used in
any form for fertilizing soil
Sprej sušenje fosfat-solubilizirajućih bakterija za proizvodnju novih biofertilizatora
No full textPhosphate-solubilizing bacteria represent a sustainable solution to cope with phosphorus unavailability in agricultural soil. However, the success of their application is highly dependent on multiple environmental factors, and a novel approach is needed for bioformulations. The present study aimed to evaluate the suitability of the spray drying method for encapsulation of phosphate-solubilizing bacteria Azotobacter chroococcum F14/2, Bacillus megaterium 11/3, and Pseudomonas putida P1. Three strains were characterized, grown under optimal conditions, and encapsulated as a whole medium-cell system using the spray drying method and maltodextrin as carrier material. The described procedure provided encapsulates with an average particle size below 5 μm, moisture content under 10%, and satisfactory powder properties. The cell viability of encapsulates (after storage) was in the following order: Bacillus megaterium 11/3 > Azotobacter chroococcum F14/2 > Pseudomonas putida P1. Additional protection during spray drying was most probably achieved by the presence of microbial exopolysaccharides, which opened the possibilities for further optimization of encapsulation procedures.Fosfat-solubilizirajuće bakterije predstavljaju održivo rešenje za suočavnje sa nedostatkom fosfora u poljoprivrednom zemljištu. Međutim, uspeh njihove primene u velikoj meri zavisi od velikog broja faktora životne sredine i potreban je novi pristup za dobijanje bioformulacija. Cilj ovog istraživanja je da se proceni pogodnost metode sprej sušenja za inkapsulaciju fosfatsolubilizirajućih bakterija: Azotobacter chroococcum F14/2, Bacillus megaterium 11/3 i Pseudomonas putida P1. Ova tri soja su okarakterisana,uzgajana pod optimalnim uslovima i inkapsulisana kao ceo sistem koji sadrži
podlogu i ćelije korišćenjem metode sprej sušenja i maltodekstrina kao nosača. Opisanim postupkom dobijeni su inkapsulati sa prosečnom veličinom čestica ispod 5 µm, sadržajem vlage ispod 10% i zadovoljavajućim svojstvima za praškaste uzorke. Ćelijska vijabilnost inkapsulata (nakon čuvanja) bila je sledećim redom: Bacillus megaterium 11/3 > Azotobacter chroococcum F14/2> Pseudomonas putida P1. Dodatna zaštita tokom sprej sušenja najverovatnije je postignuta prisustvom mikrobnih egzopolisaharida, što otvara mogućnosti za dalju optimizaciju postupaka inkapsulacij
Morphological, Pathogenic and Molecular Characterization of Sclerotinia sclerotiorum, the Causal Agent of White Rot of Cabbage (Brassica oleracea var. capitata), in Serbia
No full textSclerotinia sclerotiorum is a globally distributed necrotrophic pathogen with a broad host range, including many Brassicaceae crops. In 2021, white rot symptoms on cabbage were observed in 12 commercial fields in the northern part of Serbia. Twelve representative isolates of S. sclerotiorum, forming white colonies and black sclerotia, were selected for characterization and comparison with an isolate from sunflower, as the most important host plant in Serbia. The isolates showed significant variation in growth rate and sclerotia production, while ITS sequence analysis revealed the complete nucleotide identity and all isolates grouped within the major phylogenetic clade of S. sclerotiorum. Despite the low diversity of the global population of S. sclerotiorum, forty-four haplotypes were identified, with one predominant haplotype encompassing all Serbian isolates. When six Brassicaceae species (cabbage, cauliflower, broccoli, kale, mustard, and oilseed rape) and sunflower were inoculated, sunflower was found to be the most and cauliflower the least susceptible, while isolates from cabbage were generally more aggressive than those derived from sunflower. This work represents the first detailed characterization of S. sclerotiorum infecting cabbage in Serbia and highlights its genetic uniformity and differential pathogenic potential, which are critical factors for integrated disease management and crop rotation planning in Brassicaceae agroecosystems