From 2012 to 2019, 6-month to 2-year-old coffee (Coffea arabica) plants showing leaf blight, stem blackening, brownish, necrotic, irregular leaf spots and shoot tip dieback (Figure 1A, B, C, and D) symptoms were observed at the municipalities of Araguari, Indianópolis, Monte Carmelo, Nova Ponte and Romaria, Minas Gerais State, Brazil. Bacterial exudates from infected tissues, mainly from the shoot tip, were observed under microscopy; no bacterial exudates were found in leaf tissues. Bacterial colonies were isolated from symptomatic disinfested tissues (leaves and shoot tip) using medium 523 (Figure 1E). The isolated bacteria were facultative anaerobe, Gram-negative, cream-colored on YDC medium, growth at 37 ^oC, arginine and oxidase negative, catalase and asparagine positive (Schaad et al. 2002), and positive hypersensitivity reaction in tobacco leaves. Pathogenicity was confirmed by spraying coffee plants (at the three-leaf stage) until runoff, with a 1 × 108 CFU/mL bacterial suspension inoculate. The plants were kept in the moist chamber for 24 hours, before and after inoculation under greenhouse conditions. No symptoms were observed under the mock-inoculated plants. Disease symptoms on inoculated plants were observed 13 days after inoculation. The bacteria were then reisolated to satisfy Koch's postulates, the colony phenotypes were identical to the original ones. Bacterial genomic DNA of four isolates (UFU D1, UFU G119, UFU H1, and UFU I87) was extracted, and the 16S rRNA gene region was amplified using the 8F and 1492R universal primers, and then compared with sequences deposited in the GenBank. The results aligned closely with those of Kosakonia cowanii (GenBank NR_025566.1), with 99.4% similarity and 96% query coverage for the sequence. In addition to sequencing the 16S rRNA gene, which is considered the barcode for bacteria, other single-copy genes are necessary for species confirmation. In this study, to confirm the species and generate more data on these new isolates, 150 bp paired-end libraries were constructed and sequenced using DNBSEQ. A minimum of 1 gigabase was obtained for each isolate, and the genomes were assembled using the SPAdes genome assembler v3.15.4. Subsequently, the in-house developed algorithm SpM (Species Matching) was used to identify the species. The phylogenetic tree for the 16S gene was constructed using the maximum likelihood algorithm available in PhyML (v3.1/3.0 aLRT). The Phylogeny.fr platform was used to perform the phylogenetic reconstruction. This analysis revealed that our K. cowanii isolates (H1, D1, G119, and I87) from the coffee tree clustered with other K. cowanii strains isolated from different locations (Figure 2A). The Average Nucleotide Identity (ANI) analysis was performed using the fastANI program on all complete genomes of the Kosakonia genus obtained from the NCBI database. The results indicated that our K. cowanii isolates from the coffee tree clustered closely with other strains of the K. cowanii species (Figure 2B). Genomic analyses confirmed that all isolates belong to the species K. cowanii, corroborating the 16S rRNA gene analyses. The genomes have been deposited in NCBI with the accession numbers CP160410 (K. cowanii strain UFU H1, size 4,749,805 bp and coverage 36.21x), CP160412 (strain UFU G119, size 4,509,735 bp and coverage 31.26x), CP162577 (strain UFU D1, size 4,867,107 bp and coverage 19.0x), and CP162576 (strain UFU I87, size 4,552,151 bp and coverage 18.23x). These results are of great importance for better understanding the role of K. cowanii as a disease-causing pathogen of coffee plants. K. cowanii has already been described infecting Eucalyptus with symptoms of bacterial blight in Uruguay (Brady et al. 2009), causing disease in soybeans (Krawczyk and Borodynko-Filas 2020), also associated as endophytic in plants (Thomas et al. 2007), and as human pathogens (Yang et al. 2018). Thus, to our knowledge, this is the first report of bacterial blight caused by K. cowanii on coffee plants. The isolates are deposited in the phytopathogenic bacteria collection at Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Brazil, under the codes UFU D1, UFU G119, UFU H1 and UFU I87.

Murundus fields (wetland earth-mounds) represent a relatively understudied physiognomy in the Cerrado biome. This study aimed to evaluate the composition, life history, phytosociology, endemism, and conservation status of woody plant species in murundus fields in a forestry-dominated landscape in the Brazilian savanna. We established 40 plots, each measuring 50 × 20 m, where all live shrub-arboreal plants with a trunk diameter at the base of ≥1 cm and a height > 0.5 m were identified. Using these data, we calculated the absolute and relative values of density, dominance, and frequency, as well as the importance value index. In addition, we estimated Shannon’s and Simpson’s diversity indices and Pielou’s equability index. Our findings included 155 species, 69 genera, and 38 families in the study area. The invasive exotic species Pinus caribaea Morelet showed the highest importance value, followed by Jacaranda caroba (Vell.) DC., Miconia albicans (Sw.) Steud., Erythroxylum suberosum A.St.-Hil., and Miconia fallax DC. The pronounced presence of P. caribaea is a matter of concern and highlights the need for control measures, given its potential to hinder the regeneration of native species. We identified species occurring in various Cerrado phytophysiognomies, suggesting that murundus fields function as transitional habitats. This study underscores the importance of conserving species within the inadequately studied Cerrado physiognomy.

Alzheimer’s disease (AD) involves the accumulation of β-amyloid (Aβ), synaptic dysfunction, and neuronal loss. Given the limited efficacy of current treatments, natural bioactive molecules—such as peptides derived from kefir microbiota—are gaining interest. In silico analyses of two peptides from Brazilian kefir were carried out to assess their potential against key AD targets (Aβ, BACE1 and AChE). Docking studies showed that both peptides bind to fibrillar and monomeric Aβ, suggesting a possible preventive effect on aggregate formation. PepKLacM01 exhibited stronger binding to BACE1 and AChE, indicating potential inhibition, whereas PepKLacM02 displayed weaker and more peripheral interactions, yet maintained modulatory effects on Aβ aggregation. These findings suggest complementary mechanisms of action—aggregation prevention, enzyme inhibition, and modulation—and support further experimental validation for their potential therapeutic application in AD.

Background: Nanotechnology offers innovative approaches to combat drug-resistant diseases. Silver nanoparticles (AgNPs) have emerged as potent antimicrobial agents in vitro and in vivo. Green synthesis methods, which leverage the bioactive components of the water-soluble fractions of Brazilian kefir (whole water-soluble fraction and smaller than 10 kDa fraction), provide sustainable alternatives to conventional nanoparticles production. However, despite the documented therapeutic benefits of kefir, its potential in nanomedicine remains underexplored. Results: The successful synthesis of silver nanoparticles using water-soluble fractions of kefir was confirmed by UV-Visible spectroscopy and Fourier-transform infrared analyses. The hydrodynamic radius of nanoparticles derived from the entire water-soluble fraction was 1300 nm, while those from the smaller than 10 kDa fraction displayed a radius of 400 nm. All synthesized AgNPs exhibited a zeta potential of -30 mV. The disk diffusion method demonstrated the antimicrobial efficacy of our AgNPs against a range of multidrug-resistant bacteria and Candida fungi (p<0.0001), with no observed toxicity on Drosophila melanogasteron a long-term treatment. Conclusion:This study highlights the potential of these AgNPs as effective antimicrobial agents, particularly against drug-resistant pathogens. Future research is needed to evaluate the minimum inhibitory concentrations of our AgNPs and enhance specificity through conjugation with other compounds. Additionally, further investigations into electron microscopy analysis and various applications, such as disinfectant solutions, wound healing, and antibiotic production, will advance the utilization of kefir-derived AgNPs in healthcare.