Biofertilization with Gluconacetobacter diazotrophicus: Effects of a Native Isolate and a Reference Strain on Soil and Foliar Chemical Profiles and Economic Performance in Greenhouse Tomato Production
The intensive use of synthetic fertilizers in horticulture generates environmental and economic constraints, highlighting the need for sustainable alternatives such as plant growth-promoting bacteria. However, their effectiveness depends on strain adaptation to local conditions. This study evaluated the effect of Gluconacetobacter diazotrophicus (native isolate GIBI029 vs. reference strain ATCC 49037) under four nitrogen (0 and 100% of the recommended dose) and phosphorus (0 and 100% of the recommended dose) fertilization combinations on soil chemical properties, foliar nutrient uptake, and economic performance in greenhouse tomato production in Colombia. The native isolate was associated with higher soil nutrient levels, reaching 185.1 g/kg organic matter, 6.4 g/kg total nitrogen, 284.75 mg/kg available phosphorus, 9.32 cmol/kg calcium, and 3.93 cmol/kg magnesium. In addition, foliar nitrogen content reached 22.4 g/kg in treatments inoculated with GIBI029. These responses were associated with yields up to 106.4 t/ha, exceeding those obtained with the reference strain. Yield data were obtained from a previous study conducted under the same experimental design and environmental conditions and were incorporated here exclusively for the economic assessment. Economically, the native isolate achieved the highest benefit–cost ratio (2.65) and net income (USD 20,106/ha). A strong correlation between soil organic matter and nitrogen (r = 0.99) was observed, indicating a close association between these variables within the evaluated production system. These results suggest that strain origin may influence biofertilization efficiency and indicate that native microbial inoculants can contribute to improved agronomic and economic performance under the conditions evaluated, supporting their use in sustainable tomato production systems.
The use of microbial biostimulants has become an important strategy for improving the productivity and quality of soilless vegetable production systems. However, the potential role of lactic acid bacteria (LAB) in hydroponic crop production remains insufficiently explored. This study evaluated the effects of three LAB strains, namely Lactiplantibacillus plantarum (LP), Levilactobacillus brevis (LB), and Pediococcus pentosaceus (PP), their combined mixture, and a commercial PGPR-based product, Rhizofill, on the growth, yield, physiological performance, and nutritional quality of lettuce grown in a floating hydroponic system. The experiment was conducted under greenhouse conditions using Batavia-type lettuce cv. ‘Caipira’ in a randomized complete block design with four replications. Bacterial suspensions were applied to the nutrient solution at 7-day intervals. Bacterial inoculations significantly improved plant growth, yield, SPAD chlorophyll index, leaf sap EC, and antioxidant-related quality traits compared with the untreated control. Among the tested treatments, LP showed the strongest overall performance, increasing plant fresh weight and total yield by 34.0% and 36.0%, respectively, compared with the control. LP also enhanced total phenolic, flavonoid, and L-ascorbic acid contents, indicating a simultaneous improvement in productivity and nutritional quality. LB was particularly effective in promoting root fresh weight and produced the lowest nitrate accumulation among all treatments. Compared with Rhizofill, LP showed equal or superior performance in several growth and quality parameters, suggesting that selected LAB strains may provide an effective alternative to conventional PGPR-based microbial biostimulants. Overall, the findings highlight the potential of LAB, particularly L. plantarum, as emerging microbial biostimulants for sustainable hydroponic lettuce production.
B. Ikiz, H. Daşgan, İlker Yıldız et al.· International Journal of Agr...· 0 citations
Climate change and increasing demand for local protein resources offer a significant reason to introduce soybean (Glycine max (L.)) in Lithuania, which is beyond soybean’s typical distribution area in Europe. This study was carried out to examine the effect of microbial biostimulant inoculation in combination with chemical micronutrients on soybean under the edaphic condition of Lithuania. A three-year field trial (2023–2025) tested five treatments, including uninoculated control, Arthrobacter pascens (AP), Bradyrhizobium japonicum (BJ), BJ + AP, and BJ + AP combined with micronutrients (BJ + AP + MN) on soybean biomass, nodulation, growth, quality, yield, and yield components. BJ alone promoted most of the crop traits because the northern soil lacks biological nitrogen fixation rhizobia. It established nodulation, increased SPAD value, shoot biomass (81%), plant height (19.16%), root biomass (40.1%), protein (6.9%), pods per plant, and grain yield (33.2%) over the uninoculated control. Moreover, AP also elevated biomass and yield components significantly without nodule formation. The effects of combined biostimulant treatments in many cases were not significantly different from the single treatment of BJ. All the treatments exhibited stable performance in growing seasons, although with year-to-year climatic variation. The year 2025 gave the highest biomass and yield because of the good precipitation and temperature over that year. The most positive response of soybean grain yield was observed with inoculation of BJ + AP, which increased grain yield by 35.65% over the untreated control. This study highlights the potential of the novel epiphyte Arthrobacter pascens 13LEP5 as a highly efficient, nodule-independent biofertilizer that can match or exceed the performance of traditional inoculants in soybean production. This study suggests identifying rhizobial inoculation as a strong climate-smart strategy for the launch of a productive, low-input, organic soybean system as an expansion poleward cultivation under the edaphic condition of Lithuania.
Y. Jamil, Sulaiman Khan, Raminta Skipitytė et al.· Agriculture· 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
Biostimulants are able to increase tolerance to water and salt stress and help enhance the absorption of nutrients from the soil, in addition to increasing the extension of roots, they are also effective in the synthesis of plant hormones (such auxins, gibberellins, cytokinins) and in the capacity to make insoluble phosphorus in the soil available to plants, minimizing the effects of biotic and abiotic stresses. The objective of this study was to evaluate the phytotechnical and physiological responses of maize subjected to two water regimes and a biostimulant containing mycorrhizae and rhizobacteria of the genus Bacillus spp., through the characterization of the antioxidant response conditioned by this association. The experiment was set up in a 5x2 factorial scheme, with five treatments related to the doses of biostimulant [negative control; 0.250 kg ha-1; 0.500 kg ha-1; 0.750 kg ha-1 and 1 kg ha-1] and two water availability levels (60% and 100% of field capacity), with four replicates, totaling 40 pots. The following growth parameters were analyzed at 15 and 30 days after planting: plant height, stem diameter, number of leaves, root length and root volume, as well as the following biochemical parameters: lipid peroxidation, total peroxidase and catalase of leaf and root. The biostimulant promoted an increase in the growth of the aerial part and root system of corn plants, in addition to an adjustment of antioxidant enzymes, indicating that, up to 30 days after planting (DAP), corn plants show better adaptability to the water regime with 60% of field capacity.
Ana Thaila Rodrigues Felix, Alessandro Carlos Mesquita, Filipe de Amorim Fonseca Moura et al.· Scientia Plena· 0 citations
The targeted foliar application of indigenous osmotolerant epiphytes offers a highly effective and ecologically sustainable approach to significantly reduce synthetic fertilizer dependency while enhancing crop resilience, vegetative growth, and pathogen defense.
Satish Kumar, Meenal Rathore, Pushpendra Sharma et al.· World Journal of Microbiolog...· 0 citations
Simple Summary This study evaluated organic waste-based nutrient supplements for morel mushroom cultivation, focusing on yield, nutritional quality, and soil ecological responses. The wa-60 formulation increased yield by 28.6% while sustaining high amino acid levels, positioning it as a viable option for balancing productivity and fruit-body quality. Although wr-60 did not enhance yield, it substantially enriched soil bacterial diversity, indicating its potential for substrate amelioration and microecological restoration. Both treatments dynamically regulated soil organic matter, pH, macronutrients, microbial biomass, and enzyme activities, exhibiting a biphasic pattern of rapid initial changes followed by stabilization. Collectively, wa-60 emerged as a promising organic amendment strategy for morel production. Future research should incorporate field-scale trials and functional genomic approaches to clarify the causal roles of key microbial taxa in nutrient release and crop performance.
Li-Bing Gong, Le Wang, Li-Ping Su et al.· Biology· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
