Search Results (213)

The integration of beneficial microorganisms with sensor technologies represents a transformative advancement toward sustainable smart agriculture. This review synthesizes recent progress in combining microbial bioinoculants with sensor-based monitoring systems to enhance crop productivity, resource-use efficiency, and environmental resilience. Beneficial bacteria and fungi improve nutrient cycling, stress tolerance, and soil fertility thereby reducing the reliance on chemical fertilizers and pesticides. In parallel, sensor networks—including soil moisture, nutrient, environmental, and remote-sensing platforms—enable real-time, data-driven management of agroecosystems. Integrated microbe–sensor approaches have demonstrated 10–25% yield increases and up to 30% reductions in agrochemical inputs under optimized field conditions. We propose an integrative Microbe–Sensor Closed Loop (MSCL) framework in which microbial activity and sensor feedback interact dynamically to optimize inputs, monitor plant–soil interactions, and sustain productivity. Key applications include precision fertilization, stress diagnostics, and early detection of nutrient or pathogen imbalances. The review also highlights barriers to large-scale adoption, such as variable field performance of inoculants, high sensor costs, and limited interoperability of data systems. Addressing these challenges through standardization, cross-disciplinary collaboration, and farmer training will accelerate the transition toward climate-smart, self-regulating agricultural systems. Collectively, the integration of biological and technological innovations provides a clear pathway toward resilient, resource-efficient, and ecologically sound food production. Full article

Methanotrophs offer promising avenues for sustainable agriculture and climate mitigation. This study evaluates the efficacy of indigenously isolated methanotrophs, particularly Methylomonas Kb3, as bioinoculants in rice cultivation. Kb3-treated plants exhibited early flowering, increased height, and a grain yield up to 17% higher than that of untreated controls. A mixed inoculation of Methylomonas and Methylomagnum resulted in a 15% increase in yield, indicating limited synergistic benefit. The root-dipping method during transplantation proved to be a practical and scalable inoculation technique for farmers. Genomic analysis revealed that Methylomonas Kb3 harbours genes associated with nitrogen fixation and resistance to heavy metals and antibiotics, potentially underpinning its agronomic performance. Beyond yield enhancement, the application of methanotrophs may contribute to reduced methane emissions in flooded paddy systems, offering dual benefits for both productivity and environmental sustainability. These findings warrant multilocation trials to validate efficacy across diverse agro-climatic zones and support the development of climate-smart biofertilizer strategies. Full article

In saline soil, legumes are restricted in their growth potential by osmotic stress, ion toxicity, and oxidative damage. We evaluated five halotolerant plant growth-promoting bacteria and selected Pseudomonas putida RT12 for its exceptional EPS production, tolerance to 600 mM NaCl, strong biofilm development, and plant growth-promoting traits (ACC-deaminase 2.86 µM·mg⁻¹; IAA 144 µM·mL⁻¹). RT12 was evaluated on two varieties of peas (peas2009 and 9800-10) with and without inoculation at 0, 75, and 150 mM NaCl concentrations. RT12 markedly protected growth under severe salinity: at 150 mM, shoot length rose to 23.13 cm (peas2009) and 17.44 cm (9800-10), in contrast to 11.18 cm and 12.32 cm in uninoculated specimens; root length and dry weight demonstrated comparable recovery (root length increased from 11.00 to 22.25 cm; dry weight of peas2009 from 0.15 to 0.17 and 0.41 to 0.71 g). RT12 sustained photosynthesis (total chlorophyll increased from 43.5 to 54.5), enhanced relative water content (to 94.1% and 97.2%), elevated osmolytes (total soluble proteins rose from 7.34 to 18.12 µg·g⁻¹ FW; total soluble sugars increased from 19.1 to 41.3 mg·g⁻¹ FW), and augmented antioxidant activities (catalase increased from 2.11 to 4.70; superoxide dismutase rose from 1.20 to 4.83; peroxidase increased from 0.08 to 0.18), while reducing malondialdehyde/hydrogen peroxide levels. RT12 was significant as it inhibited the accumulation of Na⁺ (from 23.95 to 16.32 mg·g⁻¹ DW), elevated K⁺ levels (from 17.76 to 29.12 mg·g⁻¹ DW), and restored the K⁺/Na⁺ ratio to normal (from 0.74 to 1.59) in inoculated plants compared to non-inoculated ones. A multivariate analysis linked growth protection to ionic homeostasis, osmotic control, and the detoxification of reactive oxygen species (ROS). RT12 is a promising bioinoculant for cultivating peas in saline-affected soils. Full article

Maize (Zea mays L.) is a globally critical crop that faces numerous challenges, including contamination by mycotoxigenic fungi such as Aspergillus spp. The use of fungal endophytes as bioinoculants offers a sustainable strategy to improve plant resilience against biotic and abiotic stresses. Here, we evaluate the potential of Colletotrichum tofieldiae strain Ct0861 as a bioinoculant and its impact on maize-associated bacterial and fungal microbiomes. Field trials demonstrated that Ct0861 enhanced biomass and yield compared to controls, regardless of the application method (seed or foliar). Microbiome profiling showed that Ct0861 induced subtle, compartment-specific changes in microbial diversity and composition, while preserving the stability of core microbiome assemblages. Both microbiome data and qPCR quantification confirmed a significant reduction in Aspergillus spp. abundance in Ct0861-treated plants. Greenhouse assays corroborated these results: Ct0861 reduced A. flavus biomass by up to 90% and significantly lowered aflatoxin levels in infected grains. Dual-culture assays and the absence of Ct0861 in grain samples suggest an indirect biocontrol mechanism, potentially mediated by plant-induced resistance. This study provides the first evidence that Ct0861 acts as a biocontrol agent against mycotoxigenic Aspergillus spp. in maize. Beyond promoting plant growth, Ct0861 enhances food safety by reducing mycotoxin accumulation without disrupting the native microbiome, supporting its potential as a tool for sustainable crop protection. Full article

Integrating optimal plant density, microbial bioinoculants, and foliar amino acid application represents a key strategy to enhance sustainable peanut production. Therefore, the objective of this research was to investigate the combined impact of plant density (P), microbial consortium (M) bioinoculants, and foliar amino acid application (A) on the morpho-physiological and agroproductive responses of peanut production. Under field conditions, the experiment was arranged in a split–split plot with four replicates. Two plant densities of 41,667 and 83,334 plants/ha were the main plots, soil inoculation with M at 0 mL m⁻², 100 mL m⁻², and 200 mL m⁻² were the subplots, and the foliar application of VIUSID^® agro at 0 mL L⁻¹, 0.60 mL L⁻¹, and 1.20 mL L⁻¹ were the sub-subplots. Results indicated that peanut plant cultivated at a density of 83,334 plants/ha, inoculated with 100 mL m⁻² of microbial consortium, and supplemented 0.60 mL L⁻¹ of amino acid significantly enhanced the growth and physiological responses and increased peanut yield in a sustainable manner. Therefore, the findings of this study suggest that this integrated approach improved resource utilization, promoted balanced vegetative and reproductive development, and strengthened stress resilience, ultimately leading to higher productivity under sustainable management practices. Full article

Phosphorus (P) is an essential element for plant growth, yet it is only available to plants in the form of orthophosphate. In most soils, P occurs predominantly in insoluble forms, such as calcium phosphates in alkaline soils and aluminum/iron phosphates in acidic soils, limiting plant uptake. Fertilization is commonly used to overcome this limitation; however, large fractions of applied P rapidly become unavailable. Phosphorus-solubilizing bacteria (PSB) are a sustainable alternative to enhance P availability. This study evaluated the P-solubilization capacity of bacterial strains belonging to different genera isolated from different host plants, soil types, and climates (mainland Portugal, Cape Verde, and Angola). Following initial screening, the most efficient strains were tested under greenhouse conditions in soils with pH 7 and 8. Strains exhibited diverse solubilization capacities, with highly efficient PSB (phosphate solubilization index ≥ 2) accounting for 5% of the total isolates, predominantly originating from the Namib Desert (Angola) and Southern Portugal, and mainly belonging to the genera Pseudomonas, Flavobacterium, Enterobacter, Chryseobacterium and Pantoea. At pH 7, most PSB promoted maize growth, with strain C11 increasing plant P content around 2-fold compared to the control. At pH 8, fewer strains were effective, but strains F and C11 enhanced shoot weight and M shoot length by 28%, 27%, and 10%, respectively. These findings highlight the potential of selected PSB strains as next-generation bioinoculants for sustainable agriculture. However, strain selection must consider geography, crop type, and management practices to ensure consistent efficacy, thereby supporting the broader application of PSB as a precision tool for improving food security. Full article

The use of bioinoculants aligns with ecological intensification in agriculture, but their effects on crop performance and soil microbiota under different fertilization regimes remain unclear. This study evaluated the impact of a bioinoculant containing two phosphate-solubilizing bacterial strains (Priestia megaterium and Bacillus subtilis) on maize yield, root architecture, and rhizosphere microbial communities via seed inoculation in a clayey soil. Maize was cultivated for two consecutive seasons under treatments combining inoculation, phosphorus sources (triple superphosphate or reactive rock phosphate), and P doses (0 or 120 kg ha⁻¹ of P₂O₅). Root traits, phosphatase activities, and microbial diversity were assessed at flowering, while agronomic parameters and nutrient content were measured at harvest. In the first season, microbial alpha diversity was higher, accompanied by a 31.5% increase in root surface area and a 46.2% increase in P-resin availability. In contrast, the second season showed greater phosphatase activity and higher grain P and K concentrations, by 42.3% and 38.2%, respectively. Grain yield did not differ significantly between inoculated and non-inoculated treatments; however, root, plant, and microbial traits varied markedly across seasons. Principal component analysis revealed that productivity was primarily driven by seasonal variation rather than by fertilization or inoculation. These findings emphasize that the effectiveness of bioinoculants and P fertilization, as well as their influence on the microbiota, are highly context-dependent, being shaped by environmental conditions, soil nutrient availability, and crop genotype. Full article

This study presents the first molecular characterization of arbuscular mycorrhizal fungi (AMF) isolated from single-spore cultures in Morocco, specifically from the rhizosphere of date palm (Phoenix dactylifera L.) in the Figuig oasis. Nine indigenous AMF isolates were successfully established and identified through an integrative approach combining spore morphology with ribosomal DNA region sequencing (SSU–ITS–LSU). Morphological and phylogenetic analyses revealed that the isolates belonged mainly to the genera Rhizophagus and Glomus. These results provide new insights into AMF diversity in arid Moroccan ecosystems and establish a reference collection of indigenous isolates with potential applications. In particular, they open opportunities for developing bio-inoculants that can improve date palm growth, enhance resilience to environmental stresses, and contribute to sustainable agriculture and soil restoration in oasis systems. Full article

Crop productivity can be affected by biotic and abiotic stressors, and plant growth-promoting bacteria (PGPB) from the genera Bacillus and Burkholderia have the potential to maintain fruit yield and quality, as these bacteria can promote plant growth by solubilizing nutrients, fixing atmospheric nitrogen, producing phytohormones, and exhibiting antagonistic activity against pathogens. This study aimed to evaluate the effects of inoculating plants with Bacillus subtilis and Burkholderia seminalis on their morphological characteristics, fruit technological attributes and yield of common cherry tomatoes (Solanum lycopersicum L.) subjected to induced water deficit. The study was arranged on a split-plot randomized block design, with four water replacement levels (40%, 60%, 80% and 100% of crop evapotranspiration, ETc) and three inoculation treatments (Bacillus subtilis ATCC 23858, Burkholderia seminalis TC3.4.2R3 and non-inoculation). Data were subjected to analysis of variance using the F-test and compared using Tukey’s test (p < 0.05) and multivariate statistics from principal component analysis. Inoculation with Burkholderia seminalis increased the plant fresh and dry shoot and root mass, as well as root volume. Inoculation with Bacillus subtilis increased carotenoid and chlorophyll b contents. Both inoculations enhanced leaf water content in plants experiencing severe water deficit (40% of ETc). The use of these strains as PGPB increased the fruit soluble solids content. Higher productivity in inoculated plants was achieved through a greater number of fruits per cluster, despite the individual fruits being lighter. Treatments with higher water replacement levels resulted in greater yield. Inoculations showed biotechnological potential in mitigating water deficit in cherry tomatoes. Full article

Car wash wastewaters (CWW) bring growing environmental challenges due to the increasing number of vehicles worldwide and they require novel, optimized and sustainable treatment methods. They are highly heterogenous, typically containing complex mixtures of detergents, waxes, oils, petroleum derivatives, corrosion inhibitors and salts, with the composition depending on installation age, geographic location, season, and weather. This study aimed to select bacteria resistant to variable and potentially toxic CWW, capable of biodegrading organic pollutants. A total of 81 strains isolated from various environmental sites were screened for tolerance to CWW environments by performing growth inhibition tests in 20 real wastewater samples with chemical oxygen demand (COD) ranging from 122 to 2267 mg O₂/dm³. Seventeen strain candidates were chosen, identified with molecular proteomics, and further evaluated for biodegradation potential. Based on the most robust isolates, six microbial consortia were developed and examined. Biodegradation experiments were conducted at ambient temperature without active pH control and nutrient supplementation to reflect real conditions occurring in wastewater treatment practice. The best-performing consortium reduced COD by 86% within 7 days. These findings should help improve the treatment of complex CWW by highlighting the potential of thoroughly selected bacteria as effective tools for bioremediation of extremely harsh environments. Full article

Drought is a significant abiotic stressor affecting crops globally. Beneficial microorganisms, such as rhizobia, have been shown to enhance crop resilience to such stresses. In this study, we isolated a highly efficient rhizobacterial strain (Rhizobium sp. PV-6) from the root system of Phaseolus vulgaris and systematically investigated the phenotypic and physiological responses of the plants across seven growth stages under four treatments: W-NO (watering without inoculation of rhizobium), W-RHI (watering with inoculation of rhizobium), D-NO (drought without inoculation of rhizobium), and D-RHI (drought with inoculation of rhizobium). We also examined the variation in microbial communities in rhizosphere and root compartments. Physiological analyses revealed that rhizobium inoculation significantly enhanced plant height, fresh weight and dry weight, root length, lateral root number, and nodule number of red kidney beans. Alpha diversity analysis suggested that the microbial communities in the roots and rhizosphere of red kidney beans show different variant distributions. Beta diversity and species difference analysis revealed that drought treatments (D-NO, D-RHI) recruit Shinella, Nocardioides, Agromyces, Pseudomonas, and Ensifer at rhizosphere compartments, while D-RHI enrich Pseudomonas, Sphingobacterium, Paenibacillus, Bacillus, Massilia, and Lysobacter at root compartments in the T5 stage. Further, transcriptomic analysis revealed that PV-6 enhances drought tolerance in red kidney beans by modulating the expression of genes associated with abiotic stress-related genes. Our findings highlight the potential of Rhizobium sp. PV-6 as a bioinoculant for improving drought tolerance in red kidney beans (Phaseolus vulgaris), providing a foundation for designing synthetic microbial communities for crop stress resilience. Full article

To survive in saline environments, plants establish complex symbiotic relationships with soil microorganisms, including halotolerant arbuscular mycorrhizal fungi (AMF). The main objective of this study was to uncover how inoculation with a consortium of halotolerant AMF influences recretohalophyte Limonium species tolerance to long-term salinity, at physiological and molecular levels. In this study, the physiological performance, ultrastructure of leaf epidermal cells, and expression of seven genes involved in salinity response were studied in Limonium daveaui and Limonium algarvense plants exposed to 200 mM NaCl and inoculated with an AMF consortium, dominated by Rhizoglomus invernaius. An isohydric response was observed for both species after one year in salinity. Inoculation with AMF led to higher stomatal conductance for plants in non-saline conditions and improved photosystem II efficiency under salinity. In L. algarvense, inoculation enhanced stomata and salt gland epidermal area under tap water. While salinity significantly increased salt gland, stomata and pavement cells areas but not cell size. In L. daveaui, AMF led to an increased salt gland density as well as salt gland size under saline conditions. In both species, salinity increased the expression of Na⁺/H⁺ antiporter AtSOS1, aquaporin TIP5, and salt gland development related genes LbTRY, Lb7G34824 and Lb4G22721GIS2. The expression of such genes was significantly reduced in AMF-inoculated plants under salinity. Besides, higher levels of gene expression were observed in L. algarvense than in L. daveaui. Overall, our findings highlight the protective role of halotolerant AMF and emphasize their potential as sustainable effective bio-inoculants for enhancing plant salinity tolerance. Full article

Exploring microbial resources from coastal environments is crucial for enhancing food security; however, current knowledge remains limited. This study aimed to isolate and molecularly characterize bacteria associated with maize and groundnut, and to evaluate their potential as plant growth-promoting (PGP) agents. Rhizobacteria were isolated from rhizospheric soil, and endophytic bacteria were obtained from surface-sterilized and macerated plant roots. One gram of each sample was suspended in sterile distilled water in test tubes, serially diluted, and plated on nutrient agar. After incubation, distinct colonies were sub-cultured to obtain pure cultures for biochemical tests, screening for PGP traits, assessment of pH and salt tolerance, optimal growth conditions, bioinoculation potential, and molecular analysis. Out of sixty isolated bacteria, five potent strains, BS1-BS5, were identified. BS3 showed the highest mannanase activity, with a 2.3 cm zone of clearance, while BS2 exhibited high indole-3-acetic acid (IAA) and phosphate solubilization activities of 10.92 µg/mL and 10.78 mg/L. BS1 and BS4 demonstrated high drought tolerance, 0.94 and 0.98 at 10% PEG, with BS1 also showing maximum salt tolerance of 0.76. At 6.0 g and 2.0 g supplementation, BS1 and BS2 utilized 100% lactose and fructose. BS3 exhibited the highest percentage of antifungal activity, with a 30.12% inhibition rate. BS4 and BS5 promoted shoot lengths of 55.00 cm and 49.80 cm, respectively. Although the bacterial species isolated are generally considered pathogenic, their positive effects contributed significantly to maize growth. Full article

The use of plant growth-promoting bacteria (PGPB) tolerant to abiotic stress factors can enhance plant performance when applied under both optimal and stress conditions in crops. In this study, bacterial strains associated with the rhizosphere of the halophyte Distichlis spicata were isolated and characterized for their ability to produce siderophores, solubilize phosphate, synthesize indole-3-acetic acid (IAA) and exopolysaccharides (EPS), and tolerate salinity. IAA production and antioxidant capacity were further assessed under saline stress. As expected, salinity negatively impacted bacterial growth, IAA biosynthesis, and antioxidant activity—even in strains from a salt-tolerant plant. Nevertheless, all strains except RD2 maintained growth and IAA production in LB broth supplemented with up to 1 M NaCl. Five halotolerant strains (RD2, RD4, RD17, RD26, and RD27) were selected for greenhouse inoculation assays in tomato (Solanum lycopersicum) seedlings. Inoculation with RD26 significantly enhanced seedling performance, promoting tomato growth, increasing leaf area by 22%, stem diameter by 17%, shoot dry biomass by 30%, and root biomass by 27% as compared to the uninoculated control. RD27 and RD4 also improved shoot biomass by 25 and 23%, respectively. Based on 16S rRNA gene sequencing, RD26 was identified as Pseudomonas sp. and RD27 as Zhihengliuella halotolerans. These findings demonstrate that salt stress impairs plant growth-promoting traits in rhizospheric bacteria, yet selected strains such as RD26 and RD27 can significantly promote plant growth. Their use as bioinoculants represents a promising strategy for improving crop performance in saline environments. Full article

Salt–alkaline soil poses a significant challenge to soybean productivity. While plant growth-promoting rhizobacteria (PGPR) offer a sustainable strategy for stress mitigation, their field-level application remains underexplored. Here, a field experiment was conducted in the Yellow River Delta of Shandong, China, a typical salt–alkaline region. In this study, we evaluated the effectiveness of Bacillus velezensis 41S2 in enhancing soybean performance under salt–alkaline soil through integrated field trials and transcriptomic analysis. Inoculation with strain 41S2 significantly improved plant biomass, yield components, and seed yield under salt–alkaline soil, and notably increased seed protein and isoflavone contents. Physiological analyses revealed that strain 41S2 markedly reduced hydrogen peroxide (H₂O₂) accumulation, indicating alleviation of oxidative stress. Moreover, strain 41S2 modulated the levels of soluble sugars and amino acids, contributing to osmotic regulation and carbon–nitrogen (C-N) metabolic balance. Transcriptome profiling further indicated that strain 41S2 upregulated genes involved in antioxidant response, C–N metabolism, and phenylpropanoid biosynthesis, highlighting its role in coordinating multilayered stress response pathways. Overall, these findings highlight the potential of B. velezensis 41S2 as a multifunctional bioinoculant for improving salt tolerance and presents a promising tool for sustainable crop production and ecological restoration in salt–alkaline soil. Full article