Aug 2026· Ecology, environment & conservation· Vol 32, pp. S327-S334· 0 citations
Abstract
Hydroponics provides an efficient alternative to soil-based cultivation by conserving water, minimizing soil-borne diseases, and addressing land constraints. Coco peat serves as an effective growth medium due to its favorable aeration and moisture retention properties, while plant growth-promoting bacteria (PGPB) such as Phosphate-Solubilizing Bacteria (PSB) and Azotobacter are known to enhance nutrient availability through biological mechanisms. The present study investigates the influence of coco peat enriched with PGPB on early-stage plant growth under hydroponic conditions. PSB and Azotobacter were applied individually and as a consortium using seed coat and spray methods to evaluate their effects during the initial stages of plant development. PSB facilitates the solubilization of inorganic phosphates, whereas Azotobacter contributes to nitrogen fixation, potentially supporting early seedling establishment. The experiment was conducted in a controlled hydroponic setup over a short duration, and growth-related physical parameters indicative of early plant response were monitored. The results revealed that the consortium treatment exhibited enhanced early-stage growth parameters compared to individual applications across both treatment methods. The observed improvement in seedling performance suggests an interaction between PSB and Azotobacter during the initial growth phase. As this study represents a preliminary, short-term assessment, conclusions regarding long-term plant performance, crop yield, or reduction in chemical fertilizer dependency would require further experimentation and confirmation of results. However, the findings provide foundational insights into microbial-assisted early growth responses in hydroponic systems and highlight the need for extended-duration and field-scale studies to evaluate long-term agronomic implications.
Purpose Microbe-assisted zinc (Zn) biofortification offers a sustainable strategy for enhancing wheat productivity and nutritional value. This study evaluated whether two endophytic bacteria from the Zn hyperaccumulator Sedum alfredii, applied individually or as a SynCom, could improve wheat growth, Zn uptake, physiological performance, and root exudate modulation under hydroponic conditions. Methods Wheat seedlings were grown under hydroponic conditions and inoculated with SaPA1 and SaBR2 individually or as a consortium, and their impacts on growth, Zn uptake, physiological characteristics, root morphology, and root exudate metabolomics were assessed after 30 days. Results All inoculated treatments improved Zn uptake, wheat growth, plant height, and leaf photosynthetic performance relative to the control, with the SynCom showing the strongest overall effect. Zn concentrations increased by 42.49% in roots and 46.6% in shoots under the consortium treatment compared to the control. Zn accumulation was also significantly enhanced by endophytic inoculation, with the consortium producing the greatest increase, reaching about 6-fold in roots and nearly 3-fold in shoots relative to the control. Additionally, non-targeted LC–MS profiling revealed clear treatment-dependent shifts in root exudates, with the SynCom showing the strongest metabolic reprogramming and greater organic acid exudation. Conclusion These findings show that endophytic bacteria derived from a Zn hyperaccumulator can improve wheat growth, Zn uptake, physiological performance, and root exudate remodeling under hydroponic conditions. Overall, the results support the potential of endophytic bacteria, especially as a SynCom, as a microbial strategy for Zn biofortification in wheat.
Nazish Jabeen Abbasi, Ancao Pan, Jazbia Shirin et al.· Frontiers in Microbiology· 0 citations
Soil degradation is a major concern, causing a decline in crop productivity and making sustainable agricultural practices essential for humankind. Biochar and plant growth-promoting bacteria (PGPB) are currently applied as affordable and environmentally safe alternatives. Biochar, a porous, carbon-rich by-product of biomass pyrolysis, was applied at 3 % (w/w) alone (control) and in combination with microbial inoculants, including a bacterial consortium. A 15-day pot experiment was conducted under controlled conditions to evaluate the effects of biochar and plant growth-promoting bacteria (PGPB) on plant growth. This study investigates the effects of biochar and PGPB (three Pseudomonas spp. and one Diaphorobacter spp.) on rice (Oryza sativa L.) and mustard (Brassica juncea L.) when applied individually and in combination. The results were evaluated based on plant growth-promoting criteria namely root and shoot length and chlorophyll content. It was observed that biochar had a positive impact on plant growth parameters when applied individually, however in combination with bacterial inoculants, the results were significantly improved. The consortium treatment showed higher values for root length, shoot length and chlorophyll content compared with individual treatments. This study highlights the major scope and potential of utilising plant growth promoting bacteria and biochar to achieve sustainable increases in plant growth and yield. However, some treatments showed variability in results, which could be attributed to the compatibility between biochar and microbial inoculants. This underscores the need for further optimisation studies on the interaction between biochar and bacterial inoculants.
D. Ruchi, S. Sunita, G. Arpita et al.· Plant Science Today· 0 citations
Modern agriculture faces critical challenges, including climate change, soil degradation, and reliance on synthetic inputs, necessitating sustainable alternatives. A promising approach is applying microbial solutions. This study investigated the effects of a commercially available powder-formulated seed coating product containing Rhizoglomus irregularis and Azospirillum spp. on high-linoleic sunflower (Helianthus annuus L.) under field conditions at three Hungarian sites with contrasting soil properties. Plant growth parameters, yield, and the rhizosphere’s microbial carbon-source utilisation potential were assessed to evaluate treatment effects. Seed-applied inoculation increased plant height, stem diameter, and biomass, although responses varied with site conditions and sampling time. The agronomic response was highly site-dependent: the strongest effect was observed at a low-pH, phosphorus-limited site, where seed inoculation achieved a significant yield increase of 18–21%, while effects at sites with higher pH and sufficient phosphorus resulted only in minor, statistically non-significant numerical trends. Distinct shifts in culture-dependent carbon-source utilisation potential were detected by Biolog EcoPlate™ analysis, showing temporal and site-specific variability. These results indicate that seed-applied formulations offer a logistically feasible, targeted delivery method for plant-beneficial microbes, with their agronomic efficacy fundamentally governed by site-specific soil chemical profiles and baseline nutrient availability. Overall, the agronomic benefits of inoculation appear to be context-dependent and more pronounced under nutrient-limited conditions, highlighting the critical importance of site-specific application strategies and the need for further long-term studies.
Andrea Tímea Tóth, Lívia László, Katalin Posta· Agronomy· 0 citations
Drought is one of the major abiotic stresses limiting productivity worldwide, highlighting the need for sustainable strategies to improve crop resilience under water-limited conditions. This study evaluated the effects of the plant growth-promoting bacteria Bacillus aryabhattai and Pseudomonas fluorescens, applied individually or in combination, on soybean growth under well-watered and water-deficit conditions. The experiment was conducted in a completely randomized design arranged in a 2 × 4 factorial scheme, consisting of two irrigation regimes (well-watered and water deficit) and four biological treatments (control, B. aryabhattai, P. fluorescens, and co-inoculation with both bacteria). Plant growth variables, including shoot and root length, root volume, fresh biomass, and dry biomass, were evaluated after the stress period. Under well-watered conditions, co-inoculation promoted the greatest fresh root biomass and consistently increased shoot biomass compared with the untreated control. Under water-deficit conditions, B. aryabhattai alone produced the highest fresh root biomass and root volume, demonstrating superior performance in promoting root development during drought stress. Although most variables did not differ significantly among treatments, inoculated plants consistently exhibited greater vegetative growth than non-inoculated plants. These findings demonstrate the potential of B. aryabhattai and P. fluorescens as plant growth-promoting bacteria capable of enhancing soybean development, with B. aryabhattai showing particular promise for improving plant performance under water-limited conditions.
Thiago Ghedin Cappellesso, Sérgio Miguel Mazaro, Maira Cristina Schuster Russiano et al.· REMUNOM· 0 citations
Drought stress is among the most critical limitations to maize productivity, particularly under rainfed conditions. In this study, we explored the Brazilian Caatinga biome as a source of drought adapted plant growth-promoting bacteria and evaluated their potential to mitigate drought effects in maize (Zea mays L.). A total of 414 thermo-tolerant bacterial strains were isolated from soil, of which 28 Bacillus strains were able to grow under low water activity. These strains exhibited multiple plant growth-promoting traits in vitro, including exopolysaccharide production, biofilm formation, siderophore production, indole-3-acetic acid synthesis, putative nitrogen fixation, and phosphate solubilization. Twelve selected strains significantly improved root morphology, relative chlorophyll content (SPAD units), and biomass accumulation in maize seedlings under osmotic stress induced by polyethylene glycol. Notably, strain 1A11 showed the most consistent effects, promoting root growth and biomass accumulation under both stressed and non-stressed conditions, indicating constitutive growth promotion across environments, whereas other strains showed stronger responses under stress. This stability across environments strengthens its agronomic value, particularly in regions characterized by high rainfall variability. Genome sequencing of five elite strains (1A11, 5D5, 6E9, 1H10, and 2E7) identified conserved gene clusters associated with exopolysaccharide production, indole-3-acetic acid synthesis, phosphate metabolism, iron acquisition (siderophore synthesis), synthesis of volatile compounds, motility, chemotaxis, and general responses to osmotic and oxidative stress. Multi-location field trials conducted across five locations in Brazil, under rainfed conditions, indicate that strains 1A11 (Bacillus subtilis), 5D5, and 6E9 (Bacillus velezensis) consistently increased grain yield compared to the non-inoculated control and performed similarly to or better than a commercial inoculant. Mean productivity gains with the strain 1A11 reached up to 39% relative to the non-inoculated treatment across environments. These results indicate that Bacillus strains isolated from semi-arid soils were able to convert multifunctional potential into measurable agronomic gains under field conditions, demonstrating their potential as bioinoculants to enhance maize resilience under water-limited agricultural systems.
U. G. Lana, S. M. de Sousa, Bárbara Temponi Vilarino Godinho et al.· Frontiers in Plant Science· 0 citations
Background: Maize (Zea mays L.) is one of the world's most important cereal crops, and improving its productivity while reducing dependence on chemical fertilizers has become a major goal of sustainable agriculture. The potential role of plant growth promoting rhizobacteria (PGPR) as a biofertilizer evolved as appropriate substitute to neutralize adverse environmental impacts wielded by manmade agrochemical.
Objective: This study aimed to evaluate the effects of Pseudomonas fluorescens and Bacillus subtilis, individually and in combination, on the growth and yield of maize compared with conventional NPK fertilization.
Methods: A field experiment was conducted during the 2025 growing season at the Field Crops Research Station, College of Agriculture, University of Samarra, using a Randomized Complete Block Design (RCBD) with three replicates. Six treatments were evaluated: Untreated control (T1), Pseudomonas fluorescens (T2), Bacillus subtilis (T3), combined inoculation (P. fluorescens + B. subtilis) (T4), combined inoculation with NPK fertilizer (T5), and NPK fertilizer (20:20:20) only (T6). Vegetative growth and yield-related traits were recorded and statistically analyzed.
Results: Inoculation of plants with PGPR bacteria resulted in a significant improvement in both vegetative growth and yield compared to the untreated control group. Pseudomonas fluorescens (T2) exhibited the highest vegetative growth rate, recording the highest plant height (148.00 cm), leaf area (365.00 cm²), leaf area index (2.63), and number of grains per spike (688 grains) compared control group recorded (92.33 cm), (10.67 plant⁻¹), (151.73 cm²), (0.70) respectively. Bacillus subtilis (T3), achieved the highest productivity, producing the largest number of spikes per plant (2.67 spikes) and the highest spike weight (283.50 g) compared control group recorded (2.00) and (161.60 g).
Conclusion: The use of PGPR, and especially Pseudomonas fluorescens and Bacillus subtilis as potential biofertilisation agents is a promising sustainable alternative to chemical fertilisation that can enhance maize growth and production, while decreasing dependence on mineral fertilisers.
Waser saad Khalaf, Ahmed waleed Abdulrahman· International Journal of Bio...· 0 citations