Search Results (2,781)

Biodegradable alginate films containing silver nanoparticles (AgNPs) are being increasingly investigated as active agricultural materials (e.g., antimicrobial mulches) and active food packaging. However, since these materials ultimately degrade in soil after use, assessing their environmental compatibility and potential phytotoxicity upon release is crucial. The aim of this study was to synthesize films containing AgNPs in sodium alginate using xylose as a reducing agent and to determine their effect on culturable rhizosphere microorganisms and selected biochemical parameters in young arugula (Eruca vesicaria L. subsp. sativa) plants. Alginate films containing three nominal AgNP loadings (50, 100, and 150 mg L⁻¹) and a control film without AgNPs were synthesized. The films were cut into square pieces (4 cm²) and placed in 0.076 L multipots filled with peat substrate, into which arugula seeds were sown. During the experiment, the abundance of culturable rhizosphere bacteria and fungi was determined, and the young arugula plants were subjected to biochemical analyses. The results showed that the AgNP-containing films did not significantly affect the abundance of bacteria and fungi in the rhizosphere under the conditions tested. The tested films also did not markedly alter the measured parameters in the tissues of young arugula plants, including ascorbic acid, photosynthetic pigments, sugars, dietary protein, and glutathione. However, they reduced phenolic content, altered antioxidant activity, and led to detectable silver accumulation in plant tissues, especially at the highest nominal AgNP loading (150 mg L⁻¹). These findings indicate limited but selective biochemical effects during the early growth stage of arugula rather than a complete absence of plant response. Full article

Plant growth-promoting bacteria (PGPB) enhance plant development through mechanisms such as the production of indole-3-acetic acid (IAA). However, endophytic bacteria associated with aquatic plants, particularly watermeal (Wolffia spp.), remain poorly explored. This study investigated the potential of bacterially derived crude IAA extract for enhancing watermeal growth and accumulation of secondary metabolites in watermeal. This study isolated and screened endophytic bacteria from watermeal for IAA production, identifying Klebsiella variicola W1/6 as the most efficient producer. Optimization using response surface methodology (RSM) revealed optimal conditions at pH 5.84, 5 days of incubation, and 10.63% (v/v) inoculum size. Crude IAA extract significantly enhanced watermeal growth under both laboratory and greenhouse conditions. Notably, the combination of 0.5 ppm crude IAA extract with 50% chemical fertilizer produced growth comparable to that of the full fertilizer treatment, indicating reduced fertilizer requirement. These findings highlight the potential of bacterially derived IAA from K. variicola W1/6 as a microbial biostimulant for sustainable aquatic plant cultivation. Full article

Aquaponics combines aquaculture and hydroponics, offering an integrated and sustainable food production system. This study investigated the probiotic properties, plant growth-promoting (PGP) activity, and nitrifying capacity of twelve lactic acid bacteria (LAB) strains isolated from an aquaculture farm environment on the Ivory Coast for their potential application in aquaponic systems. All isolates demonstrated antagonistic activity against key pathogenic indicator strains, except Vibrio cholerae, and displayed varying levels of surface hydrophobicity (5.50 ± 0.70% to 22.83 ± 1.17%) and auto-aggregation (32.50 ± 0.08% to 52.89 ± 0.39%) after 24 h. Antioxidant activity was significantly higher in cell-free supernatants (~71–79%) than in intact cells (~30–33%). Bile salt tolerance (0.3%, 4 h) ranged from 2.13 ± 0.76% to 40.87 ± 2.12%, and survival under pH 1.5 with pepsin for 3 h varied from 4.84 ± 0.26% to 53.98 ± 13.28%. All isolates produced lactic, acetic, citric, malic, and propionic acid and exhibited amylase and cellulase activity; none showed hemolytic activity. Only LAB 11 produced indole-3-acetic acid (17.72 ± 0.06 μg/mL), siderophores, and phosphate-solubilization activity for PGP traits, and this group significantly enhanced maize seed germination (86.66 ± 5.77%) and radicle length (7.00 ± 0.52 mm) compared to the control (63.33 ± 32.14% and 4.94 ± 1.52 mm), respectively. LAB 1 and LAB 10 demonstrated the highest ammonia-oxidizing capacity in vitro and in trout pond water. LAB 1, LAB 10, and LAB 11 were confirmed by whole genome sequencing analysis to be Enterococcus faecalis strains with a favorable-safety genomic profile and probiotic characteristics. These three strains therefore represent promising candidates for consortium-based applications in aquaponics systems. Full article

Crop production is continually exposed to a wide range of abiotic stresses that negatively affect growth and yield, posing a severe threat to global food security. Plant growth-promoting bacteria (PGPB) promote nutrient assimilation, activate antioxidant enzymes, and stimulate phytohormone production to mitigate abiotic stress. However, the effective application of PGPB in the field depends on host colonization, soil specificity, and susceptibility to competitive microbial communities. Recently, non-thermal plasma (NTP) has emerged as a revolutionary tool for sustainable agriculture, making it a priority to develop efficient, low-cost, and eco-friendly strategies to enhance seed vitality and manage abiotic stress. Plasma-generated reactive oxygen and nitrogen species (RONS) have been shown to mediate intracellular redox homeostasis and the antioxidant defense signaling network. Furthermore, plasma stimulates MAPK cascades and stress-responsive genes such as LEA1, SnRK2, P5C, and the SOS pathway, ionic balance, and membrane stability, ultimately supporting plant stress adaptation to drought, salinity, and heavy metals. Plasma-induced RONS signaling activates PGPB functional traits such as root colonization, biofilm formation, nutrient mobilization, and plant growth-promoting activities. However, the molecular mechanisms underlying NTP-PGPB microbial multiple stress adaptation and the long-term ecological stability and biosafety of microbial communities remain inadequately resolved. Consequently, future integration of multi-omics approaches, synthetic microbial communities, and field-scale validation is required to explore the mechanistic advances of plasma-modulated microbiome interactions to enable agricultural applications. Full article

Exogenous application of bio-based nanomaterials provides a targeted strategy to modulate plant physiological and biochemical responses. This review synthesizes recent advancements in the foliar application of nanocellulose (NC), in particular, cellulose nanocrystals (CNC) and cellulose nanofibers (CNF), to enhance plant fitness. CNC-formed films provide physical and biochemical barriers that increase plant drought and cold stress tolerance. Topically applied CNC reduce non-stomatal transpiration and serve as insulators, allowing the flowering buds to successfully survive chilling, avoid freezing, and maintain cell membrane integrity. Simultaneously, CNC- and CNF-formed coatings are porous enough not to block the natural gas exchange essential for plants. CNC trigger internal antioxidant defense systems, upregulating reactive oxygen species-scavenging enzymes and modulating molecular signaling cascades. NC foliar treatment suppresses the growth of pathogenic bacteria and fungi, interferes with their adhesion and plant tissue penetration, and prevents biofilm formation. Thus, topical NC application could be regarded as a multi-functional tool for precision crop management and protection. Full article

Plant biostimulants are increasingly recognized as natural solutions that enhance plant growth and support sustainable agriculture. However, their effects on soil microbial communities remain poorly understood. This study evaluated three biostimulants: Plantiful™ (fermented marine algae with beneficial bacteria), CelexT07™ (fermented medicinal plants with beneficial bacteria), and Phylgreen™ (seaweed extract), compared with water and conventional NPK fertilization. Rhizospheric microbial biomass, community structure, and metabolic potential were assessed using metabarcoding, phospholipid fatty acid (PLFA) profiling, and Biolog EcoPlates™ assays. Total microbial biomass did not differ significantly from the untreated control. Similarly, bacterial biomass (7.4–9.8 µg/g soil) remained stable across treatments. Saprotrophic fungal biomass was 2–4-fold lower under Phylgreen^TM and CelexT07^TM than NPK, but comparable to the control. Bacterial and fungal communities were dominated by Actinobacteriota, Pseudomonadota, Acidobacteriota, Chloroflexota, and Ascomycota, with similar richness and diversity across treatments in wheat rhizosphere soil after 9 weeks of growth. Functional analyses revealed only modest shifts, with AWCD being significantly reduced by 43.5% under Phylgreen™ (64.11) compared with NPK (113.44), while remaining comparable to the untreated control (94.74). The network analysis results were also consistent with the previous results, indicating that biostimulant treatments maintained microbial richness. Overall, these findings support the use of the tested biostimulants as sustainable crop management tools that preserve rhizosphere microbial communities. Full article

Polygonatum cyrtonema Hua polysaccharides (PCPs) are bioactive components with antioxidant and immunomodulatory properties. However, whether the polysaccharides derived from elder Polygonatum cyrtonema exhibit superior health benefits remains unclear. This study systematically compared the in vitro fermentation characteristics, gut microbiota-modulating effects, and short-chain fatty acid (SCFA) production of PCPs extracted from three-year-old (TPP), five-year-old (FPP), and eight-year-old (EPP) plants using a human fecal fermentation model. The fermentation dynamics were evaluated by monitoring pH, OD₆₀₀, and the consumption of total and reducing sugars, while the structural degradation and compositional differences in PCPs were tracked via molecular weight distribution and monosaccharide composition analysis. The results showed that all three PCPs were degraded and utilized by gut microbiota, accompanied by decreased pH, increased OD₆₀₀, and enhanced antioxidant activities. High-throughput 16S rDNA sequencing revealed that, at the phylum level, all PCPs increased the Firmicutes/Bacteroidetes ratio. At the genus level, they reduced the abundance of harmful bacteria such as Sutterella and increased beneficial bacteria including Bifidobacterium and Megasphaera. Furthermore, gas chromatography (GC) analysis demonstrated that, compared with FPP, TPP and EPP significantly promoted the production of SCFAs. In summary, this study indicates that the in vitro fermentation characteristics and prebiotic properties of PCPs vary with growth years, and a comprehensive evaluation suggests that three-year-old Polygonatum cyrtonema Hua represents a promising raw material for the development of functional foods. Full article

Salinity stress is one of the major stressors that limits yield potential in field crops. Salinity-led imbalances in ionic and water potential, as well as oxidative damage, impair photosynthesis. Plant-growth-promoting rhizobacteria (PGPRs) have been demonstrated to mitigate salinity-stress-induced damage through various mechanisms such as biofilm and exopolysaccharide production, modulation of plant root architecture or molecular signaling involving modulation of sodium/potassium efflux transporters. PGPRs are known to induce biosynthesis and signaling of various phytohormones in plants. PGPR-derived phytohormones can in turn regulate molecular signaling involved in maintaining ion fluxes, preventing salinity-induced senescence, and reinforcing plant root architecture, thereby maintaining plant growth and development under saline conditions. In this review, we provide comprehensive advances on how PGPRs modulate and integrate biosynthesis and/or signaling of various phytohormones, such as auxins, cytokinins, gibberellin, ethylene, abscisic acid, salicylic acid, jasmonates, brassinosteroids and strigolactones, to reshape plant architecture, physiological and biochemical responses in plants under salinity. We integrate molecular evidence with morpho-physiological studies and propose a phytohormone-centric framework to select strains that optimize growth, ion homeostasis and plant stress resilience under salinity. Full article

Duckweed-associated plant growth-promoting bacteria have attracted attention for their potential to enhance duckweed biomass production. However, the mechanisms underlying isolate-specific growth promotion are unclear. This study compared the effects of two duckweed-associated bacterial isolates, Terrimicrobium sp. PS02 and Aeromicrobium sp. PS05, on the growth, biomass composition, colonization behavior, and transcriptomic responses of Spirodela polyrhiza. Biomass composition and transcriptome analyses were performed to characterize the host responses. Both isolates enhanced duckweed biomass; PS02 increased it 1.2-fold, whereas PS05 induced a significant 1.4-fold increase compared to the uninoculated control. PS05 established bacterial populations approximately one order of magnitude higher than those of PS02 and formed dense extracellular polymeric substance-mediated microcolonies on the surface. Transcriptome analysis revealed that PS05 induced 1108 differentially expressed genes, compared with 454 in PS02, indicating greater host transcriptomic reprogramming. Functional enrichment of transcriptome responses showed that PS05 preferentially regulates carbohydrate biosynthesis, central carbon metabolism, and starch biosynthesis, significantly enhancing starch accumulation and turion formation without reducing protein or photosynthetic pigment content. This study provides evidence linking bacterial colonization, host transcriptomic regulation, carbon allocation, and biomass production in duckweed, offering a basis for engineering high-performance duckweed–microbiome systems for sustainable biomass production. Full article

As key drivers of soil biogeochemical cycles, soil microbial communities play essential roles in maintaining soil fertility, nutrient cycling, and plant growth. In this study, high-throughput sequencing of 16S rRNA and ITS genes was used to investigate the diversity, the composition, and the driving factors of bacterial and fungal communities in bulk soils across four soil groups collected from different vegetation covers (forest soil (FS), soybean field (PGS), and two Atractylodes japonica cultivation soils (ALO and ALR)) under identical climatic conditions. The results showed that the bacterial α-diversity remained stable across all the vegetation types, whereas the fungal α-diversity and richness were more sensitive to the vegetation type, with the PGS generally exhibiting lower Shannon and Chao1 indices. The β-diversity analysis revealed significant differences in the microbial community structure among the vegetation types, with a stronger effect on fungi (R² = 0.737, p = 0.001) than on bacteria (R² = 0.493, p = 0.001). At the phylum and genus levels, the fungal communities displayed more pronounced shifts than the bacterial communities, which remained relatively stable. A redundancy analysis indicated that the soil chemical properties significantly shaped the microbial community structure (p = 0.002). The microbial communities in the A. japonica soils (ALO and ALR) were primarily driven by pH, available phosphorus, and available potassium, while the FS and PGS communities were more strongly influenced by soil organic carbon, total nitrogen, and nitrogen forms (NH₄⁺-N and NO₃⁻-N). The Spearman correlation and functional prediction analyses further confirmed that the key soil factors differentially regulated the abundance and ecological functions of the dominant microbial taxa. These findings demonstrate the vegetation-specific assembly of soil microbial communities and highlight the distinct edaphic drivers associated with A. japonica cultivation, providing a scientific basis for soil health management and the sustainable cultivation of this medicinal plant. Full article

The rhizosphere microbiome is critical for plant health, yet how soil type and intensive management jointly govern its assembly remain unclear. Here, we hypothesized that soil type acts as a primary environmental filter, while intensive cultivation (plant growth plus fertilization) imposes additional selective pressures that differentially shape bacterial versus fungal communities. Using flue-cured tobacco (K326) grown in clay loam and sandy loam soils under field conditions, we examined the rhizosphere microbiome at the topping stage. Intensive cultivation significantly altered rhizosphere physicochemical properties. Key nutrients, including organic matter (OM), dissolved total nitrogen (DTN), available phosphorus (AP), and available potassium (AK), were markedly enriched. Rhizosphere soil pH exhibited a bidirectional shift relative to the corresponding bulk soil, converging to a narrow range (7.4–7.8) in both soil types. Root activity and fertilization imposed contrasting selective pressures on the two microbial kingdoms: bacterial diversity declined slightly, indicating strong deterministic selection, whereas fungal diversity increased, reflecting adaptation to root-generated niches. Differential abundance analysis identified 38 bacterial OTUs as a core rhizosphere-adapted microbiome shared across both soil types, demonstrating robust fitness in the nutrient-enriched rhizosphere environment under intensive management. No shared core fungal OTUs were detected, underscoring strong soil legacy effects and higher habitat specificity in fungi. Notably, the core bacterial microbiome was dominated by K-strategists (slow-growing, resource-efficient taxa) that exhibited opportunistic traits capable of rapidly exploiting nutrient pulses in the rhizosphere. Together, these findings reveal that soil type acts as a critical filter modulating plant–microbe interactions under intensive agriculture, while bacteria and fungi employ divergent ecological strategies in response to selection pressures. This work provides both theoretical and practical insights for optimizing tobacco cultivation and sustaining soil microecological health. Full article

The degradation of Calcisols in the arid regions of Central Asia constrains sustainable agricultural production because of low organic matter content, poor aggregate stability, nutrient limitations, and increasing climatic stress. This study evaluated a rhizosphere engineering approach based on the native plant growth-promoting bacterium Pseudomonas veronii Ps-S/Sh-1503/2022 for the rehabilitation of degraded Calcisols. Four-year field experiments (2022–2025) using Sorghum bicolor assessed plant growth, rhizosphere microbial indicators, physiological responses, pathogen suppression, crop productivity, and implementation feasibility through economic and environmental assessments. Inoculation with P. veronii increased root depth by 45%, improved aboveground biomass, increased the ratio of culturable bacteria to Fusarium spp. from 6.1 to 10.3, and reduced Fusarium abundance by 29.4%. Structural equation modeling suggested that trophic support (42.1%), aggregate stabilization (27.4%), biocontrol (23.3%), and defense-related responses (7.2%) were the principal pathways associated with soil rehabilitation. Economic assessment indicated that the combined inoculation and mineral fertilization treatment provided the highest profitability, while environmental assessment estimated potential reductions in mineral fertilizer use and greenhouse gas emissions. These findings suggest that rhizosphere engineering using a native P. veronii strain represents a promising, economically viable, and climate-smart approach for improving the biological functioning of degraded Calcisols and supporting sustainable agricultural production. Full article

Agriculture faces the challenge of transitioning toward sustainable practices, driving the use of plant growth-promoting bacteria (PGPB). However, these bacteria suffer critical losses in viability due to environmental stress and drying processes. Although synthetic hydrogels offer protection, their low biodegradability and toxicity pose ecological risks, positioning dextran hydrogels produced by Leuconostoc sp. as a biocompatible biotechnological alternative, despite challenges related to their mechanical stability. The methodology employed consisted of systematic literature mapping in the Scopus database for the period 2010–2026. The search was conducted on 2 May 2026, using a defined search equation, and 447 documents were processed using RStudio (Bibliometrix), VOSviewer, and Plotly Studio to analyze trends and collaboration networks. The results of the systematic mapping reveal an exponentially growing field (R² = 0.998), led by Agricultural Sciences (23.5%) and Biochemistry (16%). China and India dominate scientific output in terms of volume, while Italy and the United States lead in qualitative impact, with researchers such as Cimini, Schiraldi, and Pandey as key references. An evolution is confirmed from the basic characterization of Leuconostoc sp. toward the development of matrices for immobilizing PGPB, reducing viability losses from 6 log to manageable levels of 4 log CFU. Cluster analysis shows a clear trend toward nanotechnology and “smart hydrogels” responsive to multiple stimuli. Finally, strategic gaps were identified in the creation of predictive release models, as well as an urgent need to democratize the technology through low-cost processes, essential aspects for consolidating sustainable precision agriculture. Full article

Microbial biostimulants and microbial plant protection products overlap in biological function, creating both R&D opportunities and regulatory challenges. In particular, multi-strain bacterial consortia may simultaneously affect nutrient mobilisation and abiotic stress tolerance, induce resistance, and demonstrate direct antagonism against phytopathogens. This multifunctionality complicates early product development because strain identity alone is sometimes insufficient in predicting product function, efficacy, or the most appropriate regulatory and claims strategy. Here, we used non-targeted LC-MS metabolomics as a hypothesis-generating tool to support formulation decisions for microbial consortia. Three bacterial consortia were compared: a full soil-oriented consortium C1 containing Bacillus spp., Rhodopseudomonas palustris, Nitrosomonas europaea, and Nitrobacter winogradskyi; a Bacillus-only consortium C2 intended for foliar stress-resilience applications; and a Bacillus-only consortium C3 grown with a chitin-related inducer to promote biocontrol-associated metabolism. Metabolomic profiling revealed clear differences between formulations. The full consortium C1 showed higher relative abundances of features putatively associated with biofertilising and growth support, whereas the Bacillus-only consortium C2 contained features putatively associated with biocontrol and induced resistance that were not detected in C1 under the applied criteria. The addition of the chitin-related inducer (C3) did not yield a completely distinct metabolite profile but increased the relative abundance of selected features putatively associated with biocontrol, while decreasing features putatively annotated as auxin-related or associated with abiotic stress responses. These results suggest that non-targeted metabolomics can help differentiate metabolic profiles putatively associated with biostimulant- and plant-protection-oriented formulations and thereby support prioritisation before extensive greenhouse or field testing. By linking formulation, medium composition, and microbial interactions to measurable metabolic signatures, metabolomics provides an evidence-based, hypothesis-generating framework for formulation development and the prioritisation of subsequent efficacy trials. Full article

Severely saline–alkaline land degradation poses a considerable challenge to sustainable agriculture, owing to high salinity, elevated pH, and nutrient deficiency. To address this, a salt-tolerant nitrogen-fixing bacterium (Bacillus sp.) and a microalga (Chlorella pyrenoidosa) were applied—alone, in combination, or with sheep manure—in a pot experiment with six treatments to examine their individual and combined effects on soil amelioration and wheat (Triticum aestivum L. cv. Jinchun 6) growth. We specifically assessed whether the three-component system outperforms single or dual applications. The bacterial–algal co-inoculation (BA) markedly outperformed single inoculations: shoot biomass increased by 117% and soil organic matter (SOM) by 130%, compared with the control. BA also alleviated oxidative stress, as evidenced by reduced malondialdehyde (MDA) content and elevated superoxide dismutase (SOD) and peroxidase (POD) activities. Scanning electron microscopy (SEM) observations confirmed tight bacterial attachment to algal surfaces. Incorporating sheep manure (BAM) further enhanced these benefits, achieving the lowest pH and electrical conductivity (EC), the highest SOM and available-nutrients, and the greatest wheat biomass. 16S rRNA sequencing showed that BAM increased microbial diversity, shifted community structure, and enriched beneficial genera (Sphingomonas, Flavihumibacter, and Fuscovulum) that were positively correlated with soil nutrient availability and plant stress tolerance, while the halophilic genus Halomonas declined. Collectively, the bacteria–algae–manure co-application establishes positive feedback between soil improvement and functional microbiome recruitment, offering a promising strategy for the remediation of severely saline–alkaline soil. Full article