Search Results (964)

Anemia represents one of the most frequent systemic complications of inflammatory bowel disease (IBD), with a consistently higher prevalence reported in patients with Crohn’s disease (CD) compared with ulcerative colitis (UC). While chronic inflammation, impaired iron absorption, and intestinal blood loss are recognized contributors, microbiome-mediated mechanisms influencing host iron availability remain insufficiently explored. Emerging evidence indicates that CD-associated dysbiosis is characterized by an increased abundance of siderophore-producing bacteria, particularly members of the Enterobacteriaceae family. Because siderophores are high-affinity iron-chelating molecules capable of competing with host iron acquisition systems and partially escaping lipocalin-2-mediated sequestration, their expansion may contribute to reduced luminal iron bioavailability. In this systematic review, we analyzed comparative microbiome studies published between 2016 and 2026 that directly evaluated microbial differences between CD and UC. CD microbiota consistently demonstrated enrichment in siderophore-associated taxa relative to UC. Based on these findings, we propose that microbiome-driven iron competition may represent an additional mechanistic contributor to the increased prevalence and persistence of anemia observed in CD. Although direct in vivo quantification of siderophore activity in IBD remains limited, the convergence of ecological, functional, and strain-level microbiome evidence supports a biologically plausible interaction between microbial iron-scavenging strategies and host iron metabolism. Full article

Background/Objectives: Cefiderocol (FDC) is a siderophore-containing cephalosporin that retains activity against many β-lactamase-producing bacteria, such as New Delhi metallo-β-latamase-producing (NDM) K. pneumoniae. Its use in critically ill patients is still limited, since the recommended dosing regimens are mainly derived from studies on healthy subjects, while critical illness is often associated with critical alterations in drug pharmacokinetics. Therefore, the aim of this study was to investigate FDC pharmacokinetic/pharmacodynamic (PK/PD) parameters in real-life patients based on their body weight and renal function. Methods: Patients with K. pneumoniae infections and indications for FDC were enrolled. Drug quantification in plasma was performed at the steady state at different timings. PK/PD targets of fCmin > 4 mg/L (most common) and more stringent targets of fCmin > 8 and 12 mg/L (4× and 6× the EUCAST breakpoint MIC) were considered in relation to patients’ characteristics, 14 days of microbiological eradication and 30-day mortality. Results: Ten patients were enrolled in this study. Mortality, as well as the failure to achieve microbiological eradication, increased with BMI. In a PK/PD point of view, all patients reached the PK/PD targets of fCmin > 4 mg/L and > 8 mg/L, while only 20% reached a fCmin > 12 mg/L, with a key influence of renal function. However, no significant association was found between PK/PD target attainment and treatment outcomes. Conclusions: Our study may be useful for the real-world use of FDC, highlighting the impact of renal function on the achievement of ideal PK/PD thresholds. Nevertheless, the lack of a significant association between PK/PD and outcomes, partially due to the small sample size, highlights the complex impact of patients’ clinical conditions other than drug PK. Full article

Plant growth-promoting rhizobacteria (PGPR) foster sustainable and environmentally friendly agriculture by promoting plant growth and development. PGPR colonize the root rhizosphere, rhizoplane and root tissues, where they drive organic matter turnover and nutrient cycling, thereby increasing the (phyto)availability of essential macro- (P, N, K, S, Ca, Mg) and micronutrients (Fe, Zn, Mn, Mo, Co, Ni, Cu, B). This process relies on various mechanisms, including acid secretion (rhizospheric acidification and metal chelation), siderophore production (binding Fe, Zn, and other metals) and hydrolytic enzyme-mediated catalysis (phosphatases, phytases). Some of these microorganisms can also modulate the phytohormonal balance, reshaping root architecture and enhancing nutrient uptake, and even can alleviate abiotic stress or serve as biocontrol agents, contributing to pathogen resistance. Even though plant cultivation practices relying solely on synthetic fertilizers rapidly increase crop yield and productivity, they eventually result in crops poor in essential micronutrients and trace elements. This may contribute to micronutrient malnutrition in the human population. On the contrary, PGPR enhance both crop yield and nutritional quality. Therefore, in utilization with other nutrient sources, PGPR provide a promising and scalable approach towards advancing environmentally sustainable agriculture systems. Full article

Trichoderma asperellum and T. asperelloides are two cryptic species that have potential for use as biocontrol and biofertilizer (B&B) agents. Comparison of the reference genomes of the two species revealed that each species had seven chromosomes, but Trichoderma asperellum has about 1000 more genes than T. asperelloides. The number of genes coding for chitinases, cellulases, xylanases, secreted proteases, and genes involved in soil and plant health was slightly greater in T. asperellum than in T. asperelloides. Moreover, T. asperellum had five more genes than T. asperelloides involved in the synthesis of secondary metabolites like peptaibols and siderophores. The B&B genes were distributed on all the chromosomes. No duplicate genes were found for any of the enzymes searched. The investigation also revealed that T. asperellum had 15 copies of the internal transcribed spacer (ITS) region of ribosomal DNA compared to only seven copies in T. asperelloides. Further transcriptomic, proteomic, and efficacy studies are needed to determine the impact of the missing genes in T. asperelloides on its B&B activities compared to those of T. asperellum. The search for B&B genes in T. asperelloides was hindered by the lack of annotation for the genome. Thus, comparison only involves B&B genes searched in T. asperellum and whether homologs to the genes were available or missing in T. asperelloides. A comparison between additional strains of the two species is essential to show whether the data in this study apply to all intraspecies strains of the two species. Full article

Fusarium solani is an emerging pathogen responsible for Fusarium-related diseases in durian trees in Thailand. Several chemical fungicides and biocontrol agents are ineffective in controlling these diseases, which affects durian trees and reduces yields. This study aimed to identify soil-derived bacteria with biocontrol activity against F. solani that surpasses traditional biocontrol bacteria. The characteristics and biocontrol efficacy of effective isolates were analyzed. Four isolates from 107 bacterial isolates were identified as effective biocontrol agents against F. solani. Isolate S301 exhibited the highest inhibition at 74.31%, exceeding that of the traditional biocontrol bacterium Bacillus subtilis. These isolates antagonized F. solani by producing siderophores, fungal cell wall lytic enzymes, and hydrogen cyanide, and by promoting plant growth. Molecular and phylogenetic analyses identified the four isolates as members of the Bacillus genus, specifically B. safensis, B. thuringiensis, B. subtilis, and B. cereus. The application of B. safensis strain S101 and B. subtilis strain S301 showed potential to reduce fungal disease symptoms on Monthong durian leaves. These findings are the first to demonstrate the potential of B. safensis and B. subtilis as promising bacterial biocontrol agents for managing F. solani-related diseases in durian trees in Thailand. Full article

The Gram-negative bacterium Pseudomonas aeruginosa produces a family of peptide siderophores called pyoverdines that play a vital role in the mechanisms by which it acquires iron from the environment. A key component of various pyoverdines is the presence of one or more copies of L-δ-N-formyl-δ-N-hydroxyornithine (fOHOrn) as an iron-binding residue. In this study, we have developed an improved preparation of a derivative of fOHOrn that is suitable for use in solid-phase peptide synthesis, incorporating a novel N-oxidation protocol and a mild final deprotection with HCl/hexafluoroisopropanol (HFIP) that circumvents the unexpected deformylation of the fOHOrn side chain under acidic conditions. We have also devised a synthesis of the cyclic peptide component of pyoverdine D exploiting a selective side-chain deprotection strategy with HCl/HFIP that allows the application of readily available amino acids with standard tert-butyl side-chain protection and which facilitates the cyclisation step. These innovations open the way towards the convergent preparation of various pyoverdines and also other natural products that contain fOHOrn residues. Full article

In this study, nine strains of plant growth-promoting rhizobacteria (PGPR) with multiple growth-promoting functions were isolated and screened from the rhizosphere of plants (Phragmites communis, Triglochin maritimum, and Alhagi maurorum) in the arid and barren regions of Western China. These strains belong to five genera: Klebsiella, Bacillus, Serratia, Pseudomonas, and Flavobacterium. The growth-promoting characteristics of these nine strains (PAP4, PA35, AC12, ACP1, AC25, TP7, TP8, TP12, and TP14) were analyzed. Furthermore, the growth-promoting potential of these PGPR strains was comprehensively evaluated through plate and pot experiments using Arabidopsis thaliana and alfalfa. The results indicate that most strains possess the ability to fix nitrogen and secrete zeatin and extracellular polysaccharides (EPS). Some strains exhibited significant traits such as phosphate solubilization, siderophore secretion, and the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase and indole-3-acetic acid (IAA). All strains showed high salt tolerance (0–8% NaCl) and were induced to secrete more EPS under salt stress. Plate experiments demonstrated that volatile organic compounds (VOCs) from the nine strains significantly promoted the root development of Arabidopsis thaliana and optimized its root architecture. Pot experiments revealed that inoculation with single strains influenced the growth of alfalfa to varying degrees; among them, strain TP14 showed the best performance, increasing plant height and shoot dry weight by 44.7% and 51.2%, respectively. Regarding microbial consortia, the combinations BD (PAP4 + TP14), ABC (PA35 + PAP4 + AC25), and ABCD (PA35 + PAP4 + AC25 + TP14) significantly improved the biomass, plant height, and stem diameter of alfalfa. The superior strains and their combinations identified in this study effectively promote plant growth. These high-performing PGPR strains provide valuable microbial resources for the development of bio-fertilizers tailored for saline–alkali and barren regions in Western China. Full article

To explore efficient and sustainable biocontrol resources against anthracnose in Begonia benariensis, endophytic fungi were isolated from healthy host tissues and screened for antagonistic activity against Colletotrichum aotearoa SWBG5. Among 31 isolates, four showed strong inhibition, and the most potent strain, QYN6, exhibited an in vitro mycelial inhibition rate of 63.67%. Based on morphology and multi-gene phylogeny (ITS, TUB2, TEF-1α), QYN6 was identified as Nigrospora sphaerica. Mechanistic assays revealed that QYN6 secretes multiple cell wall-degrading enzymes (chitinase, β-1,3-glucanase, cellulase, protease) and displays hyperparasitism against the pathogen hyphae (entwining, deformation, swelling), acting synergistically to inhibit fungal growth. In greenhouse pot trials, QYN6 achieved a biocontrol efficacy of 48.91% against Begonia anthracnose. Additionally, QYN6 significantly activated host defense responses, increasing the activities of antioxidant enzymes (SOD, POD, PPO, CAT) and the contents of soluble protein and soluble sugar. Furthermore, QYN6 exhibited multiple plant growth-promoting traits, including IAA production, siderophore synthesis, and potassium solubilization. Inoculation with QYN6 markedly improved plant height, leaf number, root length, and biomass of B. benariensis. Overall, N. sphaerica QYN6 possesses dual biocontrol and growth-promoting potential, providing a promising microbial resource and theoretical basis for green management of Begonia anthracnose. Full article

Saline ecosystems, including saline lakes, are indeed major hotbeds of microbial novelty, harboring diverse and largely unexplored microbes. The sebkha of Lake Naïla (Morocco), an ecologically protected area registered under the Ramsar Convention in 1998, remains largely unexplored. Isolation using three different selective media enabled seven phenotypically distinct actinobacterial isolates to be obtained. Molecular characterization, based on 16S RNA gene sequencing, was used to identify strains as members of the genera Streptomyces, Nocardiopsis, and Prauserella. Three strains showed antimicrobial potential against pathogenic microorganisms, with Streptomyces sp. strain 43 exhibiting the most potent effects. Additionally, all isolates displayed plant-growth-promoting (PGP) traits, including phosphate solubilization, auxin (IAA) synthesis, siderophore secretion, and ammonia production. Notably, Nocardiopsis sp. strain 42 produced the highest IAA levels (282 μg/mL), while Streptomyces sp. strain 39, Streptomyces sp. strain 43, and Streptomyces sp. strain 48 excelled in phosphate solubilization. GC-MS profiling of Streptomyces sp. strain 43 revealed a complex metabolite repertoire, including 1,2-propanediol and nonanal, highlighting the strain’s versatile secondary metabolism. These findings highlight that the sebkha of Lake Naïla represents a rich source of halophilic actinobacteria with promising dual potential for antimicrobial and biofertilizer applications. The findings provide a solid basis for new perspectives on biotechnology applications and sustainable agriculture. Full article

Due to the increased anthropogenic load, crops are polluted with heavy metals, including nickel (Ni). This is a serious environmental problem, as Ni penetrates barrier-free into cereal crops and accumulates in the grains used by humans and animals for food. Wheat is one of the main staple crops, cultivated in many countries. This study suggested that plant growth promoting bacteria (PGPB) with varying enzymatic activities could help wheat plants to cope with Ni stress by reducing Ni toxicity and regulating the metal’s homeostasis. PGPB Bacillus megaterium AFI1 has a strong phosphate-solubilizing activity and produces siderophores, while Paenibacillus nicotianae AFI2 has nitrogen-fixing and silicate-solubilizing activities. Both strains produce indole and polysaccharides and have 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. PGPB under Ni exposure (100 mg/kg of soil) significantly increased grain yield (by 34–42%) and decreased (by 20–33%) Ni content in wheat grains. PGPB also decreased malondialdehyde (MDA) and H₂O₂ levels in wheat plants under Ni stress. The contents of iron (Fe), boron (B), nitrogen (N) and phosphorus (P) decreased significantly and potassium (K) and zinc (Zn) oppositely increased significantly in all plant organs under Ni exposure. The inoculation with AFI1 mainly increased P and Fe, and the inoculation with AFI2 increased N and silica (Si) in wheat grains under Ni stress. In our experiments, under nickel exposure PGPB Bacillus megaterium AFI1 and Paenibacillus nicotianae AFI2 increased antioxidant protection of plants by decreasing the level of stress ethylene and regulating the homeostasis of nutrients in wheat plants. These PGPB can be considered as promising candidates for the development of biologicals to be used for growing plants in soils with low levels of nickel contamination. Full article

Background/Objectives: Parabens are widely used preservatives detected at trace levels in drinking water. Although their endocrine-disrupting effects are well established, their long-term impact on environmental bacteria remains poorly understood. This study investigated the effects of parabens on changes in bacterial phenotypic virulence traits and antimicrobial tolerance of bacteria within drinking water biofilms. Methods: Acinetobacter calcoaceticus and Stenotrophomonas maltophilia biofilms were grown on polyvinyl chloride coupons for 26 days under exposure to methyl- (MP), propyl- (PP), butyl-paraben (BP), or a paraben mixture (MIX) at 0.15 µg/L. Biofilm regrowth and virulence-associated traits, including motility (swimming, swarming, and twitching), extracellular enzymes (gelatinase, protease, and lipase), and siderophore production, were evaluated. The effect of prolonged MP exposure (10 weeks) on antimicrobial tolerance was assessed. Results: In A. calcoaceticus, MP reduced biofilm biomass by 32%, whereas MIX increased biomass by 25% and culturability (1.1-fold). S. maltophilia showed increased biofilm culturability with PP (50%), and increased biomass of 2.6-, 2.4-, and 1.8-fold for PP, BP, and MIX, respectively. Biofilm cells exhibited higher virulence factor production than planktonic counterparts. S. maltophilia biofilm cells exposed to BP and MIX showed enhanced swimming and swarming motility, with halo diameters up to fivefold larger than controls. Lipase production increased under BP and MIX exposure, whereas MP exposure reduced it. A MP-induced reduction in motility was observed for A. calcoaceticus and S. maltophilia. Long-term MP exposure results in reduced susceptibility to ceftazidime and minocycline in A. calcoaceticus. Conclusions: Environmentally relevant concentrations of parabens can modulate bacterial virulence traits, increasing biofilm formation, motility and lipase production, and antimicrobial tolerance. Full article

Soil salinization is a challenge for global agriculture and can affect the yield of staple crops such as maize. Plant growth-promoting rhizobacteria (PGPR) are known to play a pivotal role in enhancing plant growth and stress resilience. However, no studies so far have reported plant growth-promoting (PGP) activity in members of the genus Marinobacter. In this study, a novel strain of Marinobacter sp. ZP-590, was identified as a PGPR based on a polyphasic taxonomic analysis, which was isolated from the rhizosphere soil of Tamarix chinensis Lour. Genomic analysis revealed that ZP-590 possesses 5370 protein-coding genes, including core metabolic, catalytic, and transport functions essential for bacterial survival and plant interactions, along with multiple genes potentially associated with PGP traits such as phosphate solubilization, nitrogen fixation, and the production of siderophore and exopolysaccharide (EPS), tryptophan (a prerequisite for IAA synthesis), and amylase. These genomic predictions were functionally validated through in vitro assays confirming all predicted PGP activities. Pot experiment results suggested that inoculation with ZP-590 enhanced maize growth under saline conditions. Compared to the non-inoculated controls, the treatment significantly increased root fresh weight (14.25%; p < 0.05) and stem fresh weight (125.04%; p < 0.01), while shoot height and leaf fresh weight showed no significant changes. Metabolomic profiling revealed that ZP-590 inoculation was associated with systemic metabolic changes in maize under saline conditions. A total of 394, 262, and 601 differentially accumulated metabolites in the root, stem, and leaf, respectively. These changes were characterized by a substantial up-regulation of antioxidant compounds, notably flavonoids, and changes in carbohydrate and lipid metabolism pathways. The changes in carbohydrate and lipid metabolism pathways may contribute to the supply of energy and structural components for stress adaptation. Meanwhile, the accumulation of antioxidant compounds significantly mitigated saline-induced oxidative damage by reducing the levels of superoxide anion (O₂⁻) in leaves. In this study, Marinobacter sp. ZP-590 is characterized as a PGPR that promotes maize growth under saline conditions. These findings provide a foundation for investigating the molecular mechanisms underlying the interaction between ZP-590 and maize under saline conditions. Full article

Plant growth-promoting fungi (PGPF) have shown broad potential to improve soil conditions and enhance root growth and development. However, few studies have examined the effects of exogenous PGPF inoculation on the growth of the medicinal plant Saposhnikovia divaricata and the associated changes in the rhizosphere microbiome. In this study, Aspergillus neoalliaceus MR-86 exhibited phosphate solubilization, growth in nitrogen-free medium, potassium solubilization, IAA production, and siderophore production. PCR assays did not detect the aflatoxin biosynthesis-related genes aflR, aflS, and omtA in strain MR-86. Pot trials demonstrated that inoculation with MR-86 significantly increased the plant height and root dry weight of S. divaricata by 10.32% and 21.05%, respectively (p < 0.05). In the rhizosphere, soil pH decreased, whereas soil alkaline-hydrolyzable nitrogen and available phosphorus levels, as well as the activities of protease, urease, and cellulase, increased significantly. Illumina NovaSeq sequencing revealed that MR-86 inoculation altered the soil microbial community structure and specifically enriched several microbial taxa, including Talaromyces, Subulicystidium, and Aspergillus. Moreover, MR-86 inoculation did not alter the composition of dominant bacterial and fungal phyla, but significantly modified microbial interactions and the topology of microbial networks. Correlation analysis indicated that the specific microbial taxa Subulicystidium, Aspergillus, and Talaromyces were positively associated with soil nutrient indices, enzyme activities, and plant growth parameters. Functional prediction analysis indicated that MR-86 treatment was predicted to be enriched bacterial metabolic pathways, including flavone and flavonol biosynthesis and ether lipid metabolism, and was predicted to increase the relative abundance of functional fungal groups such as ectomycorrhizal and wood-decomposing fungi. In summary, A. neoalliaceus MR-86 may contribute to improved growth of S. divaricata by enhancing nutrient availability and transformation and by modulating the structure and function of the rhizosphere microbiome. Full article

Cannabis sativa L. is a multipurpose crop of increasing agricultural and medical relevance, whose productivity and phytocannabinoid profile are influenced not only by genotype and environmental factors but also by the composition of its microbiota. This review synthesizes current knowledge (2020–2026) on the rhizosphere and endophytic microbiota of hemp, with particular emphasis on plant growth-promoting bacteria (PGPB) and their mechanisms of action. Molecular studies indicate that hemp-associated bacterial communities are dominated by Proteobacteria, Actinobacteriota, Firmicutes and Bacteroidota, with genotype-, tissue- and developmental-stage-dependent variation. PGPB influence plant performance through direct mechanisms, including biological nitrogen fixation, phosphate solubilization, siderophore production and phytohormone synthesis (indole-3-acetic acid (IAA), gibberellins, cytokinins, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase), as well as indirect mechanisms such as antibiosis, enzyme-mediated pathogen inhibition and induction of systemic tolerance to abiotic stress. Experimental studies demonstrate that inoculation with selected strains or consortia can enhance biomass accumulation, improve germination and root architecture, increase resistance to Fusarium oxysporum and modulate cannabinoid and terpene profiles. Importantly, plant responses are cultivar-specific, highlighting the need for genotype-tailored microbial formulations. Full article

Aspergillus fungi are a source of low-molecular compounds of various structures possessing biological activities. We investigated the secondary metabolite profile of the soil fungus A. calidoustus VKM F-4916. The strain was found to synthesize new metabolites attributed to furoisocoumarins, which we named asperisocoumarin J and K, and a known siderophore desferritriacetylfusigen. The structure of asperisocoumarin J and K were determined by mass spectrometry and NMR spectroscopy. Asperisocoumarins J, K and desferritriacetylfusigen possessed a phytotoxicity, inhibiting the lettuce root growth. Sow thistle leaf and wheat leaf cuttings were sensitive to the action of asperisocoumarin J and K at a concentration of 5 mg/mL. Analysis of the structures of furoisocoumarins (asperisocoumarins J and K) using the online resource Pesti-DGI-Net showed that compounds had the physico-chemical properties favorable for pesticide development, in particular, fungicides and herbicides. An in-depth study of the phytotoxic properties of furoisocoumarins and their natural analogs is of interest in the context of the search for new herbicide compounds. Full article