BIOREpository (Faculty of Biology, University of Belgrade)
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Further insights into antimicrobial and cytotoxic potential of Achillea millefolium herb methanol and dichloromethane extracts
No full textThe objective of this study was to investigate chemical composition, antimicrobial and cytotoxic activities of dried methanol and dichloromethane extracts of the flowering tops (herb) of yarrow, Achillea millefolium L. (Asteraceae) collected from natural habitat in Serbia. This plant, predominantly distributed in the northern hemisphere, is widely used in folk medicine, but also as an important crop for pharmaceutical and cosmetic industries, primarily due to its appetite-stimulating, choleretic, gastroprotective, spasmolytic, analgesic, anti-inflammatory, astringent, antioxidant and/or antimicrobial activities. GC-FID and GC-MS analysis of unsaponifiable fraction of dichloromethane extract showed that the most abundant compounds were α-amyrin, β-sitosterol, one taraxasterol isomer and β-amyrin. LC-MS analysis of methanol extract revealed 28 phenolic compounds, predominantly caffeoylquinic acids, as well as apigenin and luteolin type flavonoids. Further, microdilution assay showed that both extracts possess moderate antimicrobial activity against Listeria monocytogenes (both MICs 1.25 mg mL−1) and Candida albicans (MICs 2.5 and 0.3125 mg mL−1, respectively). Investigation of the antibiofilm effects showed that methanol extract significantly inhibited biofilm formation of L. monocytogenes, but did not disrupt L. monocytogenes mature biofilm. Additionally, the reduction in L. monocytogenes motility was induced by methanol extract in dose dependent manner. Furthermore, MTT assay showed that cancer A549 and HCT 116 cell lines were more sensitive to the action of dichloromethane extract (both IC50 values 0.7 mg mL−1). Both extracts exhibited greater toxicity to cancer than to normal MRC-5 cells, as well as selective antimicrobial effect against L. monocytogenes and C. albicans. The results of bioactivity testing of chemically characterized A. millefolium extracts represent good basis for further investigations of this crop with the aim of widening its industrial application and justifying cultivation of the investigated yarrow population.M21a5.612055322
Current state of plant conservation translocations across Europe: motivations, challenges and outcomes
No full textPlant translocation is a conservation technique increasingly used around the world. In Europe, numerous unpublished initiatives have resulted in scattered information in grey literature that is difficult to access. This represents a major obstacle to the exchange of information and experience among scientists, practitioners and competent authorities. To help filling this gap, we launched a large-scale questionnaire survey with 39 questions relating to methods, motivations, problems encountered and outcomes, supplemented by a screening of scientific publications, grey literature and national/regional databases. We gathered data on 3211 plant translocations across the European continent carried out on 1166 taxa in 28 countries, which represents the largest dataset of its kind in the world to date. Target translocated species were mainly forbs from grassland habitats and had a conservation status of greater concern nationally than globally. Practitioners mainly used plug plants originating from a single source (the geographically closest to the target site). Weather events and plant diseases were the most often unanticipated problems noticed by respondents. Through monitoring, it was found that most populations flowered but often did not reproduce and could not persist for more than five years, showcasing the challenge that translocations still present for conservationists. This work will be useful in linking conservationists and enabling them to save time and resources by more easily identifying the best practices suited to their target species, with the ultimate aim of improving the science and practice of plant translocations in Europe and beyond.M213,076979234
The effects of subchronic intermittent theta burst stimulation on behavioral performance, learning and memory, and components of glutamatergic signaling in healthy adult Wistar rats
No full textM3
Causal Variants in CHRNA1 and CHRNB1 Genes for Anti-acetylcholine Receptor Antibody Positive Myasthenia Gravis: Evidence from Bayesian Fine-Mapping and Genetic Association Study
No full textAutoantibodies target the acetylcholine receptor (AChR) in 85% of myasthenia gravis (MG) patients. Genomic studies highlighted the association of genes encoding AChR subunits (CHRNA1 and CHRNB1) and MG in European populations. Additionally, Mendelian randomization revealed rs4151121 at the CHRNB1 locus as a potential causal variant. Here, we performed Bayesian fine-mapping of the CHRNA1 locus using GWAS summary statistics, a linkage disequilibrium matrix and functional annotations. The GWAS lead hit rs35274388 was identified as a causal variant overlapping with the promoter region (p < 0.01). Next, we performed a candidate gene study including 1038 participants from Serbia. Rs4151121 minor allele G was associated with late-onset MG (LOMG) (OR = 1.327, 95% CI = 1.084-1.625, p = 0.006, pperm = 0.007). Carriers of the rs4151121 GG and AG genotypes had an almost 1.5-fold increased risk of developing LOMG. A borderline association of the rs35274388 minor allele A with MG was observed (OR = 1.478, 95% CI = 1.009-2.166, p = 0.044, pperm = 0.060). Individuals with AA and GA genotypes also showed a nearly 1.5-fold higher risk of developing MG. In silico-identified causal variants at the CHRNA1 and CHRNB1 loci represent risk factors for MG in European populations, and to a greater extent for LOMG. Studies on non-European populations and functional research are needed to elucidate the role of AChR genes in the genetic architecture and development of MG.M214.
Diversity and activity of AHL-lactonases in Bacillus spp. from various environments
No full textDisrupting quorum sensing (QS) pathways in animal and plant pathogenic bacteria is an effective strategy to mitigate infections without promoting antibiotic and pesticide resistance. This approach inhibits the production of virulence factors, biofilm formation, and toxin production, reducing bacterial pathogenicity. In plant health protection, Bacillus spp. are extensively researched and utilized as biocontrol agents; however, the potential of their AHL-lactonase-producing ability, which plays a key role as a QS inhibitor of Gram-negative pathogens, remains largely unexplored. This study examined the activity and diversity of QQ enzymes from Bacillus spp. isolates obtained from various natural sources, confirming their presence in previously unreported environments associated with agricultural fields (straw and manure). Our findings show that AiiA lactonase is the most dominant and highly conserved AHL-lactonase among Bacillus isolates from bulk soil, manure, and straw. Despite its sequence conservation, we observed significant variation in AiiA lactonase activities toward the N-hexanoyl-DL-homoserine lactone (C6-HSL) substrate. Furthermore, in silico analysis suggested that the Bacillus sp. YtnP lactonase may have a lower affinity for C6-HSL compared to AiiA lactonase. Finally, this research presents a selection of Bacillus isolates with high AiiA lactonase activity for potential testing against plant pathogens.M232.237
New insights into the underlying mechanism involved in the Frangula alnus antivirulence potential directed toward Staphylococcus aureus
No full textStaphylococcus aureus is a leading cause of persistent infections which are difficult to treat due to its biofilm formation capability and increased resistance to available drugs. Our previous research showed the high antibiofilm potential of the ethyl-acetate extract of Frangula alnus and its main component emodin against S. aureus so this study was conducted to elucidate the mechanism be-hind the observed activity. The main goal of this research was to examine the inhibitory effect of F. alnus ethyl-acetate extracts and emodin on S. aureus biofilm matrix components (exopolysaccharides and eDNA), persister cells, and the staphyloxanthin pigment. It was demonstrated that both substances significantly reduced the production of exopolysaccharides and the amount of eDNA, and decreased the number of persister cells in the studied strains and isolates. However, the effect on staphyloxanthin production was less pronounced, with emodin being more effective. Based on the obtained results, it could be concluded that both the ethyl-acetate extract of F. alnus and emodin are good candidates for novel antibiofilm agents acting on S. aureus biofilm at different levels.M230.911449
The Influence of Bacterial Inoculants and a Biofertilizer on Maize Cultivation and the Associated Shift in Bacteriobiota During the Growing Season
No full textMaize (Zea mays L.) relies heavily on nitrogen and phosphorus inputs, typically supplied through organic and inorganic fertilizers. However, excessive agrochemical use threatens soil fertility and environmental health. Sustainable alternatives, such as poultry manure (PM) and plant growth-promoting rhizobacteria (PGPR), offer promising solutions. This study examines the effects of a phytobiotic bacterial formulation (PHY), composed of Bacillus subtilis and Microbacterium sp., applied alone and in combination with PM, on maize’s rhizosphere bacteriobiome across key growth stages. Field trials included four treatments: a control, PHY-coated seeds, PM, and combined PHY_PM. The results show that early in development, the PM-treated rhizospheres increased the abundance of beneficial genera such as Sphingomonas, Microvirga, and Streptomyces, though levels declined in later stages. The PHY_PM-treated roots in the seedling phase showed a reduced abundance of taxa like Chryseobacterium, Pedobacter, Phyllobacterium, Sphingobacterium, and Stenotrophomonas, but this effect did not persist. In the PM-treated roots, Flavisolibacter was significantly enriched at harvesting. Overall, beneficial bacteria improved microbial evenness, and the PHY_PM treatment promoted bacterial diversity and maize growth. A genome analysis of the PHY strains revealed plant-beneficial traits, including nutrient mobilization, stress resilience, and biocontrol potential. This study highlights the complementarity of PM and PGPR, showing how their integration reshapes bacteriobiome and correlates with plant parameters in sustainable agriculture.M214.01753141
Exposing Selection and Genetic Linkage in the Evolutionary Enigmatic Balanced Lethal System in Triturus Newts
No full textA balanced lethal system is a genetic disease that results in the loss of half of the reproductive output. The best-known balanced lethal system is found in newts of the genus Triturus. In these newts, two different versions of chromosome 1, named 1A and 1B, do not recombine along a particular region. Only individuals with both versions are viable, whereas those that possess the same version twice die. We cross two Triturus species to generate F1 and F2 hybrid offspring. This allows us to follow 30 species-specific single nucleotide polymorphisms (SNPs) from across the genome, including the non-recombining region involved in the balanced lethal system, over three generations. We confirm that individuals carrying the same chromosome version twice die, whereas those that possess both versions survive. Recombination is observed outside, but not within, the region associated with the balanced lethal system. Our experiment provides a clear-cut example of Mendelian inheritance with a deadly twist, well suited to teach basic principles of natural selection and genetic linkage.M222.3e7159115
