You are currently viewing a new version of our website. To view the old version click .
  • 21 daysTime to First Decision

DNA

DNA is an international, peer-reviewed, open access journal on DNA and DNA-related technologies published quarterly online by MDPI.

All Articles (144)

Integrating Genome Mining and Untargeted Metabolomics to Uncover the Chemical Diversity of Streptomyces galbus I339, a Strain from the Unique Brazilian Caatinga Biome

  • Edson Alexandre Nascimento-Silva,
  • André Luiz Leocádio de Souza Matos and
  • Thalisson Amorim de Souza
  • + 12 authors

Background/Objectives: The escalating antimicrobial resistance crisis underscores the urgent need to explore underexplored ecological niches as reservoirs of novel bioactive compounds. The Brazilian Caatinga, a unique semi-arid biome, represents a promising reservoir for microbial discovery. Methods: In this study, we report the polyphasic characterization of Streptomyces galbus I339, a strain isolated from Caatinga soil. Whole-genome sequencing and phylogenomic analysis confirmed its taxonomic identity. In silico mining of the genome was conducted to assess biosynthetic potential. This genetic promise was experimentally validated through an integrated metabolomic approach, including liquid chromatography-tandem mass spectrometry (LC-MS/MS), nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) profiling. The anti-mycobacterial activity of the crude extract was evaluated against Mycobacterium tuberculosis. Results: The strain S. galbus I339 possesses a 7.55 Mbp genome with a high GC content (73.17%). Genome mining uncovered a remarkable biosynthetic potential, with 45 biosynthetic gene clusters (BGCs) predicted, including those for known antibiotics like actinomycins, as well as numerous orphan clusters. Genome mining uncovered a remarkable biosynthetic potential, with 45 biosynthetic gene clusters (BGCs) predicted, including those for known antibiotics like actinomycins, as well as numerous orphan clusters. Metabolomic analyses confirmed the production of actinomycins and identified abundant diketopiperazines. Furthermore, the crude extract exhibited antimycobacterial activity, with a potent MIC of 0.625 µg/mL. Conclusions: The convergence of genomic and metabolomic data not only validates the expression of a fraction of this strain’s biosynthetic arsenal but also highlights a significant untapped potential, with the majority of BGCs remaining silent under the tested conditions. Our work establishes S. galbus I339 as a compelling candidate for biodiscovery and underscores the value of integrating genomics and metabolomics to unlock the chemical diversity of microbes from extreme environments.

24 December 2025

Morphological characterization of Actinomycetota I339. (A) Colonies grown in liquid M9 medium and stained with methylene blue. (B) Aerial mycelium, displaying the intricate network of thin, branched hyphae rising from the substrate (2950×). (C) Detail of sporophores, revealing helical or spiral spore chains. (D) High-magnification image (8300×) of individual spores. (E) Schematic illustration of the Streptomyces spore morphology, showing the frontal and lateral views with allantoid curvature, as well as the 90° rotation indication to demonstrate its three-dimensionality.

In animals and humans, nutrients influence signaling cascades, transcriptional programs, chromatin dynamics, and mitochondrial function, collectively shaping traits related to growth, immunity, reproduction, and stress resilience. This review synthesizes evidence supporting nutrient-mediated regulation of DNA methylation, histone modifications, non-coding RNAs, and mitochondrial biogenesis, and emphasizes their integration within metabolic and developmental pathways. Recent advances in epigenome-wide association studies (EWAS), single-cell multi-omics, and systems biology approaches have revealed how diet composition and timing can reprogram gene networks, sometimes across generations. Particular attention is given to central metabolic regulators (e.g., PPARs, mTOR) and to interactions among methyl donors, fatty acids, vitamins, and trace elements that maintain genomic stability and metabolic homeostasis. Nutrigenetic evidence further shows how genetic polymorphisms (SNPs) in loci such as IGF-1, MSTN, PPARs, and FASN alter nutrient responsiveness and influence traits like feed efficiency, body composition, and egg quality, information that can be exploited via marker-assisted or genomic selection. Mitochondrial DNA integrity and oxidative capacity are key determinants of feed conversion and energy efficiency, while dietary antioxidants and mitochondria-targeted nutrients help preserve bioenergetic function. The gut microbiome acts as a co-regulator of host gene expression through metabolite-mediated epigenetic effects, linking diet, microbial metabolites (e.g., SCFAs), and host genomic responses via the gut–liver axis. Emerging tools such as whole-genome and transcriptome sequencing, EWAS, integrated multi-omics, and CRISPR-based functional studies are transforming the field and enabling DNA-informed precision nutrition. Integrating genetic, epigenetic, and molecular data will enable genotype-specific feeding strategies, maternal and early-life programming, and predictive models that enhance productivity, health, and sustainability in poultry production. Translating these molecular insights into practice offers pathways to enhance animal welfare, reduce environmental impact, and shift nutrition from empirical feeding toward mechanistically informed precision approaches.

18 December 2025

Conceptual overview of the nutrient-gene-phenotype axis in poultry nutrigenomics (Figure created by the BioRender software: https://www.biorender.com; accessed on 13 November 2025).

The cannabinoid receptor type 2 (CB2) is increasingly recognized as a crucial regulator of neuroimmune balance in the brain. In addition to its well-established role in immunity, the CB2 receptor has been identified in specific populations of neurons and glial cells throughout various brain regions, and its expression is dynamically increased during inflammatory and neuropathological conditions, positioning it as a potential non-psychoactive target for modifying neurological diseases. The expression of the CB2 gene (CNR2) is finely tuned by epigenetic processes, including promoter CpG methylation, histone modifications, and non-coding RNAs, which regulate receptor availability and signaling preferences in response to stress, inflammation, and environmental factors. CB2 signaling interacts with TRP channels (such as TRPV1), nuclear receptors (PPARγ), and orphan G Protein-Coupled Receptors (GPCRs, including GPR55 and GPR18) within the endocannabinoidome (eCBome), influencing microglial characteristics, cytokine production, and synaptic activity. We review how these interconnected mechanisms affect neurodegenerative and neuropsychiatric disorders, underscore the species- and cell-type-specificities that pose challenges for translation, and explore emerging strategies, including selective agonists, positive allosteric modulators, and biased ligands, that leverage the signaling adaptability of the CB2 receptor while reducing central effects mediated by the CB1 receptor. This focus on the neuro-centric perspective repositions the CB2 receptor as an epigenetically informed, context-dependent hub within the eCBome, making it a promising candidate for precision therapies in conditions featuring neuroinflammation.

11 December 2025

The epigenetic overview of CB2 receptor regulation. Ligand-activated CB2 (CB1 is shown for reference only) couples to Gi/βγ, engaging the MAPK/ERK and PI3K-AKT pathways. CNR2 expression is regulated in the nucleus by histone modifications (activating versus repressive marks), promoter CpG methylation, and non-coding RNAs (miRNA/lncRNA), which control transcription and mRNA stability. Endocannabinoids (green), phytocannabinoids (blue), and synthetic agonists (purple) are depicted at the receptor, and arrows represent activation or regulatory directionality. Created in BioRender. Kalkan, H. (2025) https://BioRender.com/oyx2kwj.

Background/Objectives: Goat and sheep farming is an important agro-economic resource in Benin. However, their milk is both underutilized and insufficiently characterized, which limits the development of innovative dairy products and raises concerns about its safety. Against this backdrop, our pioneering study set out to investigate, for the first time in Benin and using an advanced metagenomic approach, the microbial diversity present in goat and sheep raw milk. The aim was to lay the groundwork for safer and more efficient dairy valorization. Methods: To achieve this, metagenomic DNA was extracted from 20 pooled milk samples representing both animal species, followed by shotgun sequencing. Results: Analyses revealed seven dominant phyla: Bacillota (17.44–27.23%), Pseudomonadota (12.39–15.55%), Campylobacterota (3.65–5.29%), Actinomycetota (1.47–6.03%), Spirochaetota (1.14–2.02%), Apicomplexa (0.28–0.50%), and Bacteroidota (0.17–0.22%) in the raw milk of both species. However, their proportions differ. Bacillota, which was the most dominant in both types of milk, was significantly more abundant in goat (27.23 ± 5.33) than in sheep milk (17.44 ± 8.44). In sheep milk, Enterobacteriaceae (11.36 ± 5.79) were the most predominant family, followed by Streptococcaceae (5.57 ± 2.29) and Staphylococcaceae (4.51 ± 3.63). Goat milk, on the other hand, presents a different hierarchy. Streptococcaceae (6.65 ± 2.19) and Staphylococcaceae (6.43 ± 2.33) were the most abundant families, surpassing Enterobacteriaceae (5.33 ± 1.66). The genus Escherichia was the most abundant in sheep milk (6.18 ± 5.33). The genera Staphylococcus (4.50 ± 3.63) and Streptococcus (5.05 ± 1.98) were also present. In contrast, in goat milk, the genera Streptococcus (6.54 ± 2.35) and Staphylococcus (6.42 ± 2.32) were the most dominant, while the average abundance of Escherichia was much lower (1.98 ± 1.28). In terms of species, Sheep milk was dominated by Escherichia coli (6.14 ± 5.28) and Staphylococcus aureus (5.17 ± 2.28) while Klebsiella pneumoniae (2.82 ± 1.72), Streptococcus pneumoniae (1.92 ± 1.36), and Campylobacter coli (1.52 ± 1.27) were also found. In addition to a relatively high abundance of Staphylococcus aureus (6.40 ± 2.45), goat milk was characterized by the presence of Corynebacterium praerotentium (5.32 ± 2.28) and Clostridium perfringens (3.39 ± 2.09). Additional pathogens identified included Clostridioides difficile (1.17–2.00%), Clostridium botulinum (0.27–0.43%), Listeria monocytogenes, Mycobacterium tuberculosis, Helicobacter pylori (0.36–0.62%), Salmonella enterica (0.22–0.26%). As for fungi, Ascomycota were predominant, with the presence of Aspergillus fumigatus, Saccharomyces cerevisiae, Trichophyton mentagrophytes, and Candida auris. Moreover, lactic acid bacteria with technological interest such as Oenococcus oeni (0.60–0.97%), Levilactobacillus namurensis (0.25–0.44%), Lactobacillus agrestimuris, and Lacticaseibacillus rhamnosus were also detected. Conclusions: These findings provide essential insights into the technological potential and health risks associated with these milks, which are key to developing safer and more efficient local dairy value chains.

4 December 2025

Relative abundances of major microorganisms in milk from small ruminants.

News & Conferences

Issues

Open for Submission

Editor's Choice

Get Alerted

Add your email address to receive forthcoming issues of this journal.

XFacebookLinkedIn
DNA - ISSN 2673-8856