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This study aimed to analyze the chemical composition and in situ dry matter disappearance of açaí seeds treated with urea. Açaí seeds were treated with urea solutions at different concentrations (0, 5 and 7.5% CH₄N₂O). Subsequently, chemical analyses and in situ tests were carried out to evaluate the disappearance of dry matter (DM) in the periods of 0, 6, 12, 24, 48, 72, and 96 hours of incubation. The increasing inclusion of urea influenced the DM, crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF), except for mineral matter (MM). The DM content decreased with increasing urea levels, the control presented 92.99%. CP increased by 23.93% as urea inclusion increased. EE content was lower in the 5% treatment, reaching 0.79%. NDF, ADF, and lignin of the açaí seed decreased with increasing urea, with a lower content observed in the 7.5% CH₄N₂O treatment. Urea influenced the disappearance of DM, with greater loss in the 96-hour incubation in the 7.5% CH₄N₂O treatment. Açaí seeds can be included in the diet of ruminants when treated with urea.

Stingless bees are a diverse group with a relevant role in pollinating native species. Its diet is rich in carbohydrates and proteins, by collecting pollen and nectar supplies the development of its offspring. Fermentation of these products is associated with microorganisms in the colony. However, the composition of microorganisms that comprise this microbiome and its fundamental role in colony development is still unclear. To characterize the colonizing microorganisms of larval food in the brood cells of stingless bees Frieseomelitta varia , Melipona quadrifasciata , Melipona scutellaris , and Tetragonisca angustula , we have utilized molecular and culture-based techniques. Bacteria of the phyla Firmicutes, Proteobacteria, Actinobacteria, and fungi of the phyla Ascomycota, Basidiomycota, Mucoromycota, and Mortierellomycota were found. Diversity analysis showed that F. varia had a greater diversity of bacteria in its microbiota, and T. angustula had a greater diversity of fungi. The isolation technique allowed the identification of 189 bacteria and 75 fungi. In summary, this research showed bacteria and fungi associated with the species F. varia , M. quadrifasciata , M. scutellaris , and T. angustula , which may play an essential role in the survival of these organisms. Besides that, a biobank with bacteria and fungus isolates from LF of Brazilian stingless bees was created, which can be used for different studies and the prospection of biotechnology compounds.

Bees are manufacturers of relevant economical products and have a pollinator role fundamental to ecosystems. Traditionally, studies focused on the genus Melipona have been mostly based on behavioral, and social organization and ecological aspects. Only recently the evolutionary history of this genus has been assessed using molecular markers, including mitochondrial genes. Even though these studies have shed light on the evolutionary history of the Melipona genus, a more accurate picture may emerge when full nuclear and mitochondrial genomes of Melipona species become available. Here we present the assembly, annotation, and characterization of a draft mitochondrial genome of the Brazilian stingless bee Melipona scutellaris using Melipona bicolor as a reference organism. Using Illumina MiSeq data, we achieved the annotation of all protein coding genes, as well as the genes for the two ribosomal subunits (16S and 12S) and transfer RNA genes as well. Using the COI sequence as a DNA barcode, we found that M. cramptoni is the closest species to M. scutellaris.

Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC) for most of the pathogenic Vibrio strains. Two targets (uppP and yajC) are novel to Vibrio, and two targets (uppP and ompU) can be used to develop both drugs and vaccines (dual targets) against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

Summary New sequencing platforms have enabled rapid decoding of complete prokaryotic genomes at relatively low cost. The Ion Torrent platform is an example of these technologies, characterized by lower coverage, generating challenges for the genome assembly. One particular problem is the lack of genomes that enable reference‐based assembly, such as the one used in the present study, Corynebacterium pseudotuberculosis biovar equi, which causes high economic losses in the US equine industry. The quality treatment strategy incorporated into the assembly pipeline enabled a 16‐fold greater use of the sequencing data obtained compared with traditional quality filter approaches. Data preprocessing prior to the de novo assembly enabled the use of known methodologies in the next‐generation sequencing data assembly. Moreover, manual curation was proved to be essential for ensuring a quality assembly, which was validated by comparative genomics with other species of the genus Corynebacterium. The present study presents a modus operandi that enables a greater and better use of data obtained from semiconductor sequencing for obtaining the complete genome from a prokaryotic microorganism, C. pseudotuberculosis, which is not a traditional biological model such as Escherichia coli. The strategy for complete genome assembly of Corynebacterium pseudotuberculosis 316; the pipeline to work with data from semiconductor sequencer.

Characterizing the complex web of ecological interactions is a central challenge in molecular ecology. Shotgun metagenomics of environmental samples offers a powerful, high‐resolution approach, yet its potential for simultaneously generating multiple genomic resources from different trophic levels remains underexplored. This study serves as a proof‐of‐concept, using deep sequencing of a single, complex sample—the larval food of the stingless bee Tetragonisca angustula—to demonstrate the method's capacity to recover genomic information across varying template abundances. We successfully assembled three genomes of different completeness levels: a near‐complete bacterial genome (Acetilactobacillus jinshanensis, 2,097,977 bp with 0.002% ambiguous bases), a draft mitochondrial genome (T. angustula, 15,498–15,549 bp), and a fragmented chloroplast genome (Lactuca sativa, 130,532 bp with 23.47% ambiguous bases). The assembly quality gradient, observed from complete to fragmented, directly reflects the relative abundance of each DNA template in the environmental sample, demonstrating the method's sensitivity and ecological informativeness. Beyond these genomic resources, the data provided a comprehensive biodiversity profile, revealing DNA from seven major taxonomic groups, including 209 bacterial genera, 123 plant families, and 55 insect taxa. Additionally, genomic comparisons using Average Nucleotide Identity (ANI) and digital DNA–DNA Hybridization (dDDH) analyses suggest that the dominant bacterial strain represents a putative novel species within the genus Acetilactobacillus. This approach simultaneously provided insights into host genetics, food sources, and microbial communities, illustrating the potential of single metagenomic datasets to generate multiple valuable genomic resources for molecular ecology research. This study serves as a proof‐of‐concept, demonstrating that deep shotgun sequencing of a single complex sample—stingless bee larval food—can simultaneously generate multiple genomic resources. From this dataset, we assembled three genomes (a near‐complete bacterium, a draft host mitochondrion, and a fragmented plant chloroplast) with varying completeness. This assembly quality gradient directly reflects the relative abundance of each DNA template, showcasing the method's sensitivity and its utility for providing ecological insights from genomic data.

RAMOS, R. T. J.; CARNEIRO, A. R.; SILVA, A. L. C. Universidade Federal do Pará

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico

SILVA, A. Universidade Federal do Pará

Background: Pan-genomic studies aim, for instance, at defining the core, dispensable and unique genes within a species. A pan-genomics study for vaccine design tries to assess the best candidates for a vaccine against a specific pathogen. In this context, rather than studying genes predicted to be exported in a single genome, with pan genomics it is possible to study genes present in different strains within the same species, such as virulence factors. The target organism of this pan-genomic work here presented is Corynebacterium pseudotuberculosis, the etiologic agent of caseous lymphadenitis (CLA) in goat and sheep, which causes significant economic losses in those herds around the world. Currently, only a few antigens against CLA are known as being the basis of commercial and still ineffective vaccines. In this regard, the here presented work analyses, in silico, five C. pseudotuberculosis genomes and gathers data to predict common exported proteins in all five genomes. These candidates were also compared to two recent C. pseudotuberculosis in vitro exoproteome results. Results: The complete genome of five C. pseudotuberculosis strains (1002, C231, I19, FRC41 and PAT10) were submitted to pan-genomics analysis, yielding 306, 59 and 12 gene sets, respectively, representing the core, dispensable and unique in silico predicted exported pan-genomes. These sets bear 150 genes classified as secreted (SEC) and 227 as potentially surface exposed (PSE). Our findings suggest that the main C. pseudotuberculosis in vitro exoproteome could be greater, appended by a fraction of the 35 proteins formerly predicted as making part of the variant in vitro exoproteome. These genomes were manually curated for correct methionine initiation and redeposited with a total of 1885 homogenized genes. Conclusions: The in silico prediction of exported proteins has allowed to define a list of putative vaccine candidate genes present in all five complete C. pseudotuberculosis genomes. Moreover, it has also been possible to define the in silico predicted dispensable and unique C. pseudotuberculosis exported proteins. These results provide in silico evidence to further guide experiments in the areas of vaccines, diagnosis and drugs. The work here presented is the first whole C. pseudotuberculosis in silico predicted pan-exoproteome completed till today.