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At least 19 recordsLinked to original sources

PubMed2025

Engineering Polyketide Stereocenters with Ketoreductase Domain Exchanges.

Polyketide synthases (PKSs) are versatile biosynthetic megasynthases capable of producing a diverse range of natural products with many applications, including in pharmaceuticals. The stereochemical precision of PKSs makes them a powerful tool for engineering tailored, unnatural polyketides; however, modifying the stereocenters of a PKS product while maintaining production levels remains a significant challenge. In this study, we systematically tested and evaluated strategies for ketoreductase (KR) domain exchanges, the domain responsible for setting stereocenters of polyketide products. After first optimizing the method for KR exchanges, we then performed 44 KR domain exchanges on three different PKSs to obtain high production of all four stereoisomers in vivo. By testing both one- and two-module PKS systems, we investigated how downstream modules process intermediates with altered stereochemistry and found that the configuration of the α-substituents was critical for gatekeeping by the ketosynthase (KS). To overcome this constraint, we investigated two different strategies for altering the KS domain, including introducing targeted mutations in the downstream KS, and exploring boundaries in exchanging the entire functional unit from the donor PKS. Both strategies successfully modified the KS stereocontrol with distinct trade-offs; the functional unit exchange resulted in higher titer improvements, though it was more likely to break the entire PKS. This study demonstrates a comprehensive approach to successfully engineering all four stereochemical configurations in multiple PKS systems, advancing our understanding of and ability to rationally modify polyketide stereochemistry through multiple engineering strategies.

Polyketides↗

PubMed2026

Iterative Enoyl Reduction by a FabV-Family Enzyme Expands the Chemical Landscape of Discrete Polyketide Synthases.

Polyketides are a structurally diverse class of natural products with immense therapeutic potential. However, the biosynthetic output of discrete polyketide synthases (PKSs) has been constrained by a fundamental functional limitation: unlike modular Type I systems, discrete PKS systems typically lack integrated enoyl reductase (ER) activity. This constraint restricts their chemical repertoire primarily to unsaturated polyenes or aromatic scaffolds. Here, we characterize PbrC16, a FabV-family ER from a manumycin-type biosynthetic gene cluster (BGC) in Peterkaempfera bronchialis. This enzyme represents the first experimentally validated ER capable of functioning within discrete PKS architectures. In vitro biochemical reconstitution demonstrates that PbrC16 along with its homologue ScFabV catalyze iterative enoyl reductions in both β-ketoacyl-acyl carrier protein synthase III (KAS III)-dependent and highly reducing (HR) Type II PKS contexts, enabling the complete saturation of long-chain polyketide intermediates. Structural and computational analyses reveal the molecular basis for its exceptional substrate promiscuity and versatile acyl carrier protein (ACP) recognition. These findings resolve a long-standing "reductive gap" in discrete PKS biology and provide a "plug-and-play" module for the rational engineering of saturated polyketide scaffolds.

Polyketide Synthases↗

PubMed2026

Initiation of Hybrid Polyketide-Nonribosomal Peptide Biosynthesis via Two Distinct Pathways in C. elegans.

Nemamide A and B are hybrid polyketide-nonribosomal peptides that are produced by the PKS-1-NRPS-1 enzymatic assembly line in the canal-associated neurons (CANs) of the nematode Caenorhabditis elegans. These signaling molecules promote survival during and recovery from starvation-induced larval arrest. Here, using genome editing and targeted metabolomics, we probed the roles of the different domains of PKS-1 in the initiation of nemamide biosynthesis. We showed that the first four domains of PKS-1 are not required for the biosynthesis of the triene-containing nemamide A, but are required for the biosynthesis of the tetraene-containing nemamide B. By targeting genes that are highly expressed in the CANs, we identified two additional enzymes that participate in the biosynthetic pathway: the peroxisomal carnitine O-octanoyl transferase CROT-1, which is required for the biosynthesis of nemamide A, and the enoyl-CoA hydratase ECH-7, which is required for the biosynthesis of nemamide B. We heterologously expressed CROT-1 and showed that it prefers hexanoyl-CoA and octanoyl-CoA as substrates, converting them to the corresponding carnitine esters. According to our model, ECH-7 is needed to supply the starter unit for nemamide B biosynthesis, which is loaded onto the first carrier protein of PKS-1 and extended by the first module, thereby installing the double bond that is unique to nemamide B. Meanwhile, CROT-1 is needed to supply the starter unit for nemamide A biosynthesis, which is loaded onto the second carrier protein of PKS-1. Our data suggest that the biosynthetic pathways of nemamide A and B are under the control of two different initiation mechanisms and, thus, that the production of these two secondary metabolites may be independently regulated.

Animals↗

PubMed2026

Discovery of Glycosylated β-Amino Acid-Containing Macrolactams from Nonomuraea sp. 0L2P via Genome Mining.

β-Amino acid-containing macrolactams (β-AACMs) are a class of bioactive natural products characterized by nitrogen-containing starter units within polyketide-derived macrocycles. Here, we report four previously undescribed macrolactams, gruelactams A-D (1-4), from Nonomuraea sp. 0L2P, discovered through an integrated approach combining genome mining, 15N-labeling, and antibacterial screening. Their planar structures were elucidated by comprehensive spectroscopic analyses, including 1D and 2D NMR and HRESI-MS, and their configurations were partially assigned based on ROESY data and bioinformatic analysis. Genome sequencing and antiSMASH analysis identified a putative type I polyketide synthase (PKS) biosynthetic gene cluster, enabling the proposal of a biosynthetic pathway. Bioactivity assays showed that gruelactam D (4) exhibits antibacterial activity against Bacillus cereus and Staphylococcus aureus, with MIC values of 8 and 16 μg/mL, respectively. These findings expand the chemical diversity of β-AACMs and demonstrate the utility of genome-guided approaches for discovering bioactive natural products from rare actinomycetes.

Anti-Bacterial Agents↗

PubMed2026

A Wagner-Meerwein-Like Rearrangement Generates a Vinyl Group in the Biosynthesis of the Polychlorinated Lipopeptides Fischerazoles.

The discovery of structurally unusual natural products is a major inspiration in the search for novel enzymatic transformations. In this study, we employ stable isotope-labeled precursor feeding and metabolomics to reveal highly unusual cyanobacterial lipopeptides-fischerazoles A-C. These metabolites contain a polychlorinated fatty acyl-derived moiety with a vinyl branch and an N-methylated carboxamide-thiazole terminus. Most strikingly, stable-isotope-labeled precursor supplementation showed that during fischerazole biosynthesis, a linear, hexadecanoic acid-derived intermediate is processed to yield the ultimately branched alkyl moiety. The branched carbon becomes part of the vinyl group together with an S-adenosyl methionine (SAM)-derived carbon. A candidate polyketide synthase/non-ribosomal peptide synthetase (PKS/NRPS) fischerazoles biosynthetic gene cluster-fsh-was identified in the genome of the producing strain, Fischerella sp. PCC 9431. In vitro assays experimentally connected fsh genes to fischerazole biosynthesis and revealed that the SAM-dependent methyltransferase FshF catalyzes a Wagner-Meerwein-like rearrangement to generate the vinyl group from an ACP-tethered unsaturated fatty acid. The discovery of FshF, which is related to the well-characterized cyclopropane fatty acid synthases (CFASs), brings to light a new biocatalytic strategy for alkyl chain functionalization.

Lipopeptides↗

PubMed2026

Deciphering the Function and Structure of PA1216 as an S-Adenosyl-l-Methionine Binding Protein Using Differential Scanning Fluorimetry and Circular Dichroism.

Microbes produce bioactive secondary metabolites as toxins, pigments, or virulence factors. These specialized compounds are produced by nonribosomal peptide synthetases (NRPS), polyketide synthases (PKS), or hybrid NRPS/PKS pathways. The genes encoding NRPS and PKS reside in biosynthetic gene clusters (BGCs), some of which have no identified metabolite associated with them. Characterization of these orphan BGCs could provide insights into potential bioactive compounds that have yet to be discovered. Here, we characterize PA1216, a putative methyltransferase embedded within an NRPS BGC in Pseudomonas aeruginosa strain PAO1. We cloned, expressed, and purified PA1216, and developed an optimized differential scanning fluorimetry assay to measure its thermal stability, demonstrating concentration-dependent stabilization in the presence of established methyltransferase cofactors and inhibitors. We then adapted this assay for high-throughput screening of potential PA1216 substrates, identifying destabilizing compounds, including glycyl-glycine dipeptides, amino esters with aromatic or basic side chains, and N-Boc-protected amino acids. In contrast, sodium salts of organic acids stabilized PA1216. Lastly, we employed AlphaFold to construct a predictive model, revealing that PA1216 contains a Rossmann-like fold and a glycine-rich loop, typical of class I methyltransferases, and we corroborated these secondary structural elements using circular dichroism spectroscopy. Overall, these studies illuminate PA1216 function and establish a platform for characterizing cryptic gene clusters within secondary metabolic pathways.

Circular Dichroism↗

PubMed2026

Efficient rDNA-mediated multi-copy integration of gene clusters in Aureobasidium melanogenum.

Aureobasidium melanogenum is a promising non-conventional yeast chassis for synthetic biology. However, techniques recombining large genetic fragments, such as gene clusters, are still unavailable, hindering further metabolic reprogramming in this chassis. To achieve multi-copy integration of genes, we employed highly repetitive ribosomal DNA (rDNA) sequences in A. melanogenum as homologous recombination sites for large genetic fragments. First, integration efficiency of three different regions of A. melanogenum rDNA were investigated: RNA polymerase I promoter region (rDNA1, 1.0 kb), partial 26S rDNA region (rDNA2, 1.0 kb), and RNA polymerase I terminator region (rDNA3, 1.0 kb). Our findings revealed that the highest copy numbers and expression stability were observed for the short heterologous green fluorescent protein gene (gfp, 0.7 kb) and the long native polyketide synthase gene (pks, 7.0 kb) after rDNA1-mediated integration. Specifically, the copy numbers reached 7.0 and 8.0 for gfp and pks, respectively, and they remained stably expressed in the genome after 120-h subculturing. Furthermore, an 11.0 kb gene cluster (comprising the native pks, phosphopantetheinyl transferase (npg1), and scytalone dehydratase genes (scd) responsible for melanin biosynthesis) was integrated at the rDNA1 site, resulting in stable recombination with 15.0 copies and an approximately 12-fold increase in melanin production. Overall, the convenience and efficiency of the proposed rDNA-mediated multi-copy insertion strategy will facilitate superior metabolic engineering of A. melanogenum chassis cells.

Multigene Family↗

PubMed2026

Integrated proteomic and acetylomic analyses reveal the metabolic reprogramming associated with increased tylosin-equivalent concentration in Streptomyces xinghaiensis sf106-B1.

Deciphering the metabolic basis of high-yield antibiotic production in Streptomyces is crucial for strain optimization. Atmospheric and room-temperature plasma (ARTP) mutagenesis of Streptomyces xinghaiensis sf106 generated a mutant with a 30% increase in tylosin-equivalent concentration (μg/mL). 4D-FastDIA quantitative proteomics identified 279 differentially abundant proteins enriched in the Type I polyketide synthase (PKS) pathway, with increased abundance of key macrolide-biosynthesis-related proteins. Lysine-acetylome profiling identified 1152 differentially abundant acetylation sites and revealed altered acetylation of enzymes involved in fatty acid metabolism and the tricarboxylic acid (TCA) cycle, suggesting adjustments in central metabolism associated with acyl-CoA precursor availability and energy generation. Integration of proteomic and acetylomic data suggests coordinated changes in protein abundance and lysine acetylation associated with the increased tylosin-equivalent concentration. These results highlight candidate nodes for rational metabolic engineering of S. xinghaiensis.

Streptomyces↗

PubMed2026

Biosynthesis and Glycosylation of Antarlides, the Polyene Macrolides Possessing Androgen Receptor Antagonistic Activity.

Antarlides (ATLs) are tetraene macrolides discovered from Streptomyces spp. They demonstrated excellent antagonist activities toward mutated androgen receptors (ARs) related to the drug resistances in AR-targeted prostate cancer treatment. Herein, a biosynthetic gene cluster (BGC) of type I modular polyketide synthases (PKSs) from S. conglobatus ATCC 31005 was verified to be responsible for the biosynthesis of ATLs in the heterologous host S. lividans SBT5. The atl BGC was also activated in situ in S. conglobatus by equipping a strong promoter for the PKS genes operon. Unexpectedly, a new glycosylated product, ATL D1, was produced in the heterologous expression. ATL D1 was also generated in the S. conglobatus mutant bearing activated atl BGC through the introduction of a GT1 family glycosyltransferase gene mgt from S. lividans. Enzymatic analysis showed that the protein MGT catalyzed the glycosylation of ATL D to yield ATL D1 by attaching a β-d-glucose to the C11-hydroxyl position. Moreover, site-directed mutation of MGT resulted in an iterative glycosylation to yield ATL D2 bearing a disaccharide at the C11-hydroxyl. These results offer a platform for constructing efficient biosynthetic pathway of ATLs, and the O-glycosylation could be applied to improve the pharmaceutical properties of ATLs.

Glycosylation↗

PubMed2026

Discovery of Sphaeriaurantins as Rapid-Acting Antiplasmodials with Dual Activity in Blood and Liver Stages.

The rapid emergence of resistance in the malaria-causing protozoan Plasmodium falciparum has heightened the demand for treatments with novel modes of action. Having evolved to produce a myriad of structurally diverse natural products (NPs) as defenses against soil-dwelling parasites including protozoa, Actinomycetota strains are a promising source for the discovery of NPs as antiplasmodial drug leads. Herein, the selective inhibition of P. falciparum is reported for five distinct NP families from Actinomycetota, including an unprecedented family of glycosylated type II polyketides termed sphaeriaurantins (SPAs). The structures of SPAs were established through the combination of MS and NMR spectroscopic data analysis, derivatization and comparison of the deoxyhexose moieties to authentic standards, and quantum chemical calculations, including 1H and 13C NMR chemical shifts and electronic circular dichroism (ECD) spectra. The three isolated SPA congeners reveal that the characteristic pseudodimeric structure of the SPA family of NPs, likely introduced at a late stage of the SPA biosynthesis, is highly relevant for the observed low nanomolar activity. SPA A exhibits a rapid killing profile, with activities across all intraerythrocytic stages, and potent liver stage efficacy, as well as a low propensity for resistance development. Taken together, these results suggest a mode of action that most likely is distinct from the existing antimalarials, supporting SPA A as a promising antimalarial drug lead for further development.

Plasmodium falciparum↗

PubMed2025

Exploring biosynthetic potential of the endophytic Penicillium turbatum BLH34 using whole-genome sequence analysis and molecular networking.

An in-depth genomic and metabolomic investigation was conducted on the endophytic fungus Penicillium turbatum BLH34, isolated from Macleaya cordata. Hybrid sequencing (Illumina-Nanopore) generated a high-quality 27.9 Mb genome (GC 48.6%) encoding 9798 proteins, with functional annotation linking 5350 genes to the NCBI non-redundant database and 3404 to KEGG pathways. AntiSMASH analysis uncovered 35 biosynthetic gene clusters (BGCs), 23 of which lacked homology to known pathways, highlighting BLH34's potential for novel metabolite discovery. Molecular networking (GNPS) and LC-MS/MS identified 19 specialised metabolites, including antimicrobial polyketides. Bioassays demonstrated potent inhibition against Staphylococcus aureus (36 mm), Bacillus subtilis (28 mm) and Escherichia coli (24 mm), underscoring its pharmaceutical relevance.

Penicillium↗

PubMed2026

Unveiling Aziridine-Containing Natural Products by Genomic and Spectroscopic Approaches.

Aziridine-containing natural products are prized for their potent bioactivities, yet their scarcity and poorly understood biosynthesis have limited systematic exploration. Here, we address this by integrating genome mining with a 1H-13C coupled HSQC metabolomic approach that exploits the distinctive NMR signatures of aziridines, enabling their direct detection from complex extracts. This strategy unveiled the desertolides, the first macrolides incorporating a rare terminal 2-methyl-aziridine-2-carboxylate moiety. Genetic and isotopic studies identified a dedicated biosynthetic subcluster (desA-desN) that assembles and installs this unit from glutamate, and heterologous expression confirmed the self-sufficiency of this subcluster. Direct MS evidence reveals the aziridine moiety covalently bound to the active-site Cys113 of DesN, establishing this KAS III homolog as the first dedicated aziridine-transferase and a promising tool for polyketide engineering. Bioinformatic analysis uncovered over 50 biosynthetic gene clusters, suggesting that this aziridine-associated biosynthetic logic may be more widespread than currently appreciated. This work establishes a tractable platform for the targeted discovery and engineered biosynthesis of aziridine-containing natural products, opening this underexplored pharmacophore to systematic interrogation.

Aziridines↗

PubMed2026

Characterization and genomic analysis of Bacillus halotolerans G3-2: a potential biocontrol agent against apple Alternaria leaf blotch disease.

BACKGROUND: Apple Alternaria leaf blotch (ALB) is a devastating disease threatening the apple industry worldwide. Biocontrol offers an effective and environmentally friendly alternative for disease management. RESULTS: Bacillus strain G3-2 exhibits strong antagonistic activity against Alternaria alternata (a major causal pathogen of ALB). In dual-culture assays, G3-2 inhibited A. alternata by 88.39%; in detached-leaf inoculation assays, it reduced the lesion area by >88%. 16S rRNA sequencing and phylogenetic analysis identified this strain as Bacillus halotolerans. Oxford Nanopore Technology (ONT) sequencing generated a 4.18-Mb complete genome (43.8% G + C) containing 4149 protein-coding genes, 30 rRNAs and 86 tRNAs. CAZy annotation identified 182 genes encoding carbohydrate-active enzymes (CAZymes), including glycoside hydrolases, glycosyltransferase, and carbohydrate esterases, suggesting potential for glycosylated secondary metabolite production. AntiSMASH analysis detected nine biosynthetic gene clusters, including those for surfactin, fengycin, bacillaene and laterocidine. Plate assays confirmed that G3-2 has the ability to produce protease, cellulase and siderophore. Moreover, it exhibits ~70% inhibition against several other phytopathogenic fungi. CONCLUSIONS: These findings demonstrate that G3-2 suppresses A. alternata through antibiosis (lipopeptides and polyketides), nutrient competition (siderophores) and cell-wall degradation (proteases and cellulases). Moreover, our study revealed that it has great potential to be used as a broad-spectrum, environmentally friendly biocontrol agent. © 2026 Society of Chemical Industry.

Alternaria↗

PubMed2026

Genomic signatures of host-range divergence in the generalist Beauveria bassiana and the specialist Beauveria brongniartii.

Entomopathogenic fungi of the genus Beauveria are widely used biological control agents that infect diverse insect hosts and can also associate with plants as rhizosphere colonizers and endophytes. Within this genus, Beauveria bassiana is a cosmopolitan generalist, whereas Beauveria brongniartii exhibits a narrower host range, primarily targeting soil-dwelling coleopteran larvae with limited evidence of plant colonization. To explore genomic differentiation associated with this ecological divergence, the commercially exploited B. brongniartii strain BIPESCO2 and B. bassiana ATHUM 4946 were sequenced using Oxford Nanopore technology, followed by comparative genomic analyses across multiple strains. Orthology identified species-specific gene families, although overall genome architecture and core gene content were highly conserved. The CAZyme repertoires were nearly identical, indicating retention of a versatile enzymatic toolkit supporting plant association, saprotrophy, and insect pathogenicity. In contrast, biosynthetic gene clusters displayed substantial variation, including structural remodeling of Beauveria-specific virulence-associated clusters and expansion of type I polyketide synthase clusters in B. brongniartii. Effector prediction revealed a conserved core of largely uncharacterized proteins alongside species-specific orthogroups enriched in adhesion-, immunity-, and cuticle-interaction domains. Together, these findings indicate that host-range divergence in Beauveria is associated with compartmentalized genomic differentiation, particularly in secondary metabolism and a limited subset of lineage-specific virulence factors, rather than in the conserved core infection machinery.

Beauveria↗

PubMed2026

Genome mining reveals an architecturally expanded pyoluteorin-associated biosynthetic gene cluster and a divergent flavin-dependent halogenase-like sequence in deep-sea Pseudomonas Aeruginosa from the Gulf of Guinea.

BACKGROUND: Marine deep-sea environments harbour microorganisms with extraordinary biosynthetic potential, yet their secondary metabolite repertoires remain largely uncharacterised. RESULTS: This study reports the isolation, phenotypic characterisation, and whole-genome analysis of Pseudomonas aeruginosa strain E1, recovered from deep Atlantic seawater (Gulf of Guinea, ~2500 m depth), which exhibits antifungal activity against multidrug-resistant Candida parapsilosis. Three presumptive P. aeruginosa isolates (E1, E17, and E44) showed > 99% 16S rRNA gene sequence identity to P. aeruginosa reference sequences, while whole-genome dDDH analysis of strain E1 yielded 95.2% (95% CI: 93.6-96.4%; formula d4) relative to the P. aeruginosa type strain DSM 50071ᵀ (= ATCC 10145ᵀ), supporting its species-level assignment. Antifungal screening and PCR-based detection of flavin-dependent halogenase genes identified strain E1 as the primary candidate for genomic investigation. Illumina whole-genome sequencing produced a 6.33 Mb draft genome assembly (113 contigs, 5862 protein-coding genes, 66.4% GC content). Genome mining with antiSMASH 8.0 identified 27 biosynthetic gene clusters (BGCs) spanning nonribosomal peptide synthetase (NRPS), polyketide synthase (PKS), phenazine, terpene, and metallophore pathways. Region 7.1 of strain E1 harbours a predicted 50.8 kb pyoluteorin-associated BGC, comprising 34 genes, substantially larger than its terrestrial counterpart (~ 22 kb, ~ 17 genes), and featuring nine transport genes and three regulatory elements. Phylogenetic analysis resolved three halogenase genes: ctg7_146 showed 98.7% amino acid identity to PltA, and ctg7_149 showed 99.2% amino acid identity to PltM, supporting their annotation as PltA-like and PltM-like components of the predicted pyoluteorin biosynthetic pathway. Among the characterised reference enzymes included in this analysis, ctg7_143 showed the highest amino acid identity to PltM from P. fluorescens Pf-5. However, the identity remained low at approximately 30.4%, supporting its placement as a divergent FDH-like sequence rather than a close PltM orthologue. CONCLUSION: This study provides the first comprehensive genomic characterisation of a pyoluteorin-BGC-harbouring marine P. aeruginosa strain, demonstrating conservation of the core biosynthetic machinery alongside an expanded transport architecture and a divergent FDH-like sequence that may represent a candidate for future biochemical investigation. These findings expand current knowledge of FDH-like sequence diversity in deep-sea bacteria and support further investigation of Gulf of Guinea microorganisms as a potential source of biosynthetic and enzymatic diversity.

Multigene Family↗

PubMed2026

Evaluation of Indigenous Bacillus Strains from Asian Fermented Foods for Probiotic Properties.

Bacillus species hold particular importance due to their versatile enzymatic repertoire and ability to synthesize diverse bioactive metabolites. In this study, two fermented food-derived strains, Bacillus siamensis BB3 (from douchi) and Bacillus velezensis TMA10 (from tapai) were evaluated for their probiotic, anti-microbial and functional potentials. Both strains exhibited desirable probiotic characteristics, including desirable tolerance to simulated gastric and intestinal conditions, with BB3 showing greater acid tolerance than TMA10. Safety assessments confirmed the absence of hemolytic activity, virulence factors and antibiotic resistance genes. Whole genome sequencing showed that the strains harbored genomic sequences for a wide range of metabolites, including non-ribosomal peptides and polyketides. Ethyl acetate (EtOAc) extracts from both strains demonstrated broad-spectrum anti-microbial activity against several indicator microorganisms, including Listeria grayi, Bacillus cereus, Serratia marcescens, Escherichia coli, and Pseudomonas aeruginosa, with TMA10 additionally inhibiting MRSA and Streptococcus mutans. Liquid Chromatography-Mass Spectrometry profiling identified key anti-microbial compounds, namely surfactins, macrolactins, bacillaene from BB3 and TMA10. In addition, difficidins were also detected from TMA10. Genomic analysis further indicated diverse carbohydrate utilization capacities; both strains encoded pathways for sucrose, raffinose-family oligosaccharides and lactose metabolism, while TMA10 possessed pathways for trehalose, glucomannan and arabinoxylan degradation. Both strains also showed anti-oxidant activity, with enhanced effects observed in their cell-free supernatants and heat-killed preparations. Overall, these findings highlight BB3 and TMA10 as promising candidates for the development of fermented food-derived Bacillus probiotics and functional cultures with anti-microbial, anti-oxidant, and broad carbohydrate-utilization capabilities.

Bacillus↗

PubMed2026

Microbial allies in a cotton pest: A descriptive account of associated microbiota dynamics in Dysdercus cingulatus across development.

BACKGROUND: Hemipteran insects harbour several symbiotic partners, mainly bacteria, which play pivotal roles for hosts like dietary provision, support overall physiology, xenobiotic degradation and manipulate/regulate behaviour. Most of these symbionts usually reside and operate from the digestive tracts of the animals. Cotton is one of the major cash crops in India and Dysdercus cingulatus (D. cingulatus) though a secondary pest, is causing significant destruction of cotton bolls, poor lint quality and reduce oil content of seeds. Premature opening of cotton bolls often leads to bacterial and fungal infections, thus resulting in extensive economic loss worldwide. D. cingulatus is a hemimetabolous insect that comprises of developmental stages like egg, nymph (5 instar stages), and adult. The present work explored the ontogeny specific diversity in the associated microbiota and predicted their probable functional inputs in D. cingulatus. RESULTS: The data obtained using 16S rRNA gene sequencing (NovaSeq 6000) revealed presence of members of Proteobacteria (65.83%), Firmicutes (24%), Actinobacteria (10%) phyla throughout the ontogeny of D. cingulatus. Highest alpha diversity of these symbiotic bacteria was recorded in the third instar nymphs in contrast to rest of the developmental stages. Among all the observed genera, Stenotrophomonas, Hungatella and Glutamicibacter were predominant from egg to adult stages. MicFunPred, a tool used for predicting the probable functional inputs of these symbionts, hinted at their probable stage specific contribution in crucial biochemical pathways such as polyketide biosynthesis, ascorbate/aldarate metabolism, pentose phosphate and glyoxylate cycles, steroid hormone and peptidoglycan biosynthesis, and glycolysis/pyruvate metabolism. CONCLUSIONS: The primary investigations on the ontogenetic composition and diversity of associated microbiota, suggest dynamic shifts in D. cingulatus, concurrent with their probable functions/roles in the host development and metabolism. To the best of our knowledge, this is the first report on symbiotic microbiota variation across the developmental stages of D. cingulatus that provides preliminary descriptive observations that may guide future functional and experimental investigations into microbiota-based pest management.

Animals↗

PubMed2026

Draft genome sequence data of Streptomyces antibioticus SCBA4 isolated from the Soils of Surigao del Sur, Philippines.

The draft genome of Streptomyces antibioticus SCBA4 isolated from the soils of Surigao del Sur, Philippines is reported here. S. antibioticus is a member of the phylum Actinomycetota, a diverse group of Gram positive, high G+C content bacteria well known for their production of a variety of bioactive compounds. Sequencing using the Illumina NovaSeq 6000 platform yielded a 8,616,999 bp genome across 36 contigs with 7621 coding sequences, 87 tRNA, and 1 tmRNA. Consistent with the members of the same phylum, the GC content was 71.83% and was found to contain putative gene clusters of secondary metabolites such as NRPs, terpenes and polyketides. The genome sequence has been deposited at NCBI under the accession number JBSWZT020000000.

Actinobacteria↗