Coinoculation of Pantoea phytobeneficialis PF55 and Trichoderma harzianum ESALQ 1306 enhances soil microbial activity and agronomic performance in onion

Bioformulations of Entrophospora lutea enriched with biostimulants for growth promotion and control of Rhizoctonia root rot in lupine

Arbuscular mycorrhizal fungus (AMF) Entrophospora lutea was previously selected as a highly compatible isolate for lupine, and the main objective of the present study was to further improve its performance and practical applicability by developing two E. lutea formulations using peat and vermiculite carriers enriched with various biostimulants. Incorporating biostimulants into AMF formulations can enhance fungal performance and root symbiosis. The first formulation contained proline, ascorbic acid, and hemicellulose, whereas the second contained proline, humic acid, and mannitol. Both formulations improved AMF performance by increasing the number of infective propagules and root colonization rate. Their efficacy against Rhizoctonia root rot in lupine was evaluated in comparison with unamended E. lutea and the fungicide Rizolex under greenhouse and field conditions. Under greenhouse conditions, Formulation 2 increased plant survival to 92% and reduced disease severity to 24.2%, compared with 48% survival and 65.8% disease severity in the infected control. Root colonization reached 78% and 69% for Formulations 1 and 2, respectively, compared with 53% for the unamended E. lutea. These improvements were associated with enhanced plant growth, nodulation, nitrogenous activity, and enhanced antioxidant enzyme activities. Formulation 2 showed a more pronounced effect with increased proline accumulation and caused 82.6% reduction in H2O2 accumulation compared with the infected control. Under field conditions, both formulations improved yield compared with the untreated control across the two growing seasons. No significant differences were observed between the AMF formulations and Rizolex for most evaluated parameters. These findings demonstrate that the developed biostimulants-enriched AMF formulations are effective and environmentally friendly alternatives to chemical fungicides for controlling R. solani root rot in lupine, while improving plant growth and productivity.

Caracterização morfofisiológica, molecular e funcional de Mycobacterium agroflorensis com potencial para o desenvolvimento de bioinsumos e promoção do crescimento vegetal

The growing demand for sustainable agricultural systems has stimulated the development of microbial bioinputs capable of reducing dependence on mineral fertilizers while improving the efficient use of natural resources. In this context, the prospecting and characterization of plant growth-promoting bacteria represent a promising strategy to increase agricultural productivity and support environmental sustainability. This study aimed to perform the morphophysiological, molecular, and functional characterization of the experimental strain Mycobacterium agroflorensis, evaluating its potential for application as an agricultural bioinput. The research included macroscopic and microscopic characterization, cultivation on Middlebrook 7H10 medium, assessment of bacterial growth under different temperature and pH conditions, molecular identification based on 16S rRNA gene sequencing, and investigation of plant growth-promoting mechanisms, including phytohormone production, phosphate solubilization, siderophore production, and genes associated with plant–bacteria interaction. Agronomic assays were also conducted under controlled environmental conditions, combined with Internet of Things (IoT)-based environmental monitoring, to evaluate bacterial inoculation in different crop species. The results demonstrated that M. agroflorensis exhibited high phenotypic stability, optimal growth at 30 °C and pH 7.0, morphological characteristics consistent with the genus Mycobacterium, and functional traits associated with plant growth promotion. Bacterial inoculation improved plant development and demonstrated promising potential for application in sustainable agricultural systems. These findings highlight the biotechnological potential of M. agroflorensis as a candidate for the development of agricultural bioinputs, contributing to low-carbon agriculture and advancing research in agricultural microbiology.

Impact of Rhizophagus irregularis and Trichoderma sp. Inoculation on Cassava (Manihot esculenta Crantz) Agronomic Parameters

Background: In Côte d’Ivoire, cassava (Manihot esculenta Crantz) is cultivated throughout the country and represents an important source of income and food security. However, its production commonly involves chemical inputs that may contribute to declining soil fertility. Aims: This study evaluated the effects of Rhizophagus irregularis and Trichoderma sp. on cassava growth and yield. Place and Duration of Study: The study was conducted in two stages: a two-month in vivo cultivation phase at the Ecology Research Centre in Abidjan, southern Côte d’Ivoire, followed by a 10-month field phase in Azaguié, south-eastern Côte d’Ivoire. Methodology: The Yacé and TMS30572 cultivars were grown in vivo and under field conditions and inoculated at planting with R. irregularis (RI) and Trichoderma sp. (TRI). The fungi were applied separately and in combination (RI + TRI). Under field conditions, NPK (10-18-18) fertiliser served as the positive control for yield evaluation. Results: After two months, stem diameter, plant height, number of leaves, and leaf area were enhanced by RI and RI + TRI, whereas the effect of TRI varied with the plant organ and cultivar. For each cultivar, mycorrhizal colonisation intensity and frequency did not differ significantly between the RI and RI + TRI treatments, confirming the mycotrophic response of cassava. The RI, NPK, and RI + TRI treatments produced statistically comparable yields within each cultivar. For Yacé, yields were 18.56 t/ha with RI, 18.87 t/ha with NPK, and 19.07 t/ha with RI + TRI. The corresponding yields for TMS30572 were 28.76, 28.96, and 29.22 t/ha, respectively. Conclusion: Under the tested conditions, RI alone and RI + TRI produced cassava yields comparable to those obtained with NPK fertiliser and therefore showed potential for supporting more sustainable cassava production.

Glomus iranicum var. Tenuihypharum as a Biofertilizer Modulates Soil Microbial Community Composition and Enhances Soil Carbon Dynamics in Nectarine Cultivation

The development of biofertilization strategies based on arbuscular mycorrhizal fungi (AMF) represents a promising approach to enhance crop productivity and soil health while reducing the environmental footprint of conventional fertilization. This study evaluated the effects of Glomus iranicum var. tenuihypharum inoculation on soil physicochemical properties, abundance and diversity of soil microbial communities, and physiological performance of nectarine ( Prunus persica var. nucipersica ) under Mediterranean field conditions. Soil inoculation with G. iranicum var. tenuihypharum significantly increased soil organic carbon, microbial biomass, and basal respiration, together with enhanced plant photosynthetic rate and stomatal conductance. These improvements were accompanied by early, but transient shifts in soil microbial community composition. The structure of the fungal community exhibited a marked alteration at the initial sampling point (30 days after application). Nevertheless, the differences in fungal community composition between inoculated and control soils diminished by the second sampling (90 days after application). This trend suggests a transient shift in plant–soil communication dynamics. Bacterial assemblages also responded, showing a reduction in Actinobacteria (e.g., Rubrobacter , Solirubrobacter ) and an increase in Acidobacteria and Gammaproteobacteria. Additionally, the abundance of the ammonia‐oxidizing archaeon Nitrososphaera increased following inoculation, suggesting potential effects on nitrification processes. Overall, Glomus iranicum var. tenuihypharum enhanced soil carbon storage and microbial activity, while stimulating plant physiological performance, without causing long‐lasting alterations to the native microbiome. These results highlight the potential of products containing Glomus iranicum var. tenuihypharum as biofertilizers as part of a sustainable strategy to improve soil functionality, nutrient cycling, and crop productivity in Mediterranean fruit agroecosystems.

Molasses-amended siderophore biofertilizer reshapes the rhizosphere microbiome, promotes growth and reduces lipid peroxidation in Ocimum basilicum L

Introduction Siderophore-producing bacteria and their metabolites represent promising components of next-generation biofertilizers, yet their effects on plant physiology and soil microbiome structure remain insufficiently understood. Methods We developed a liquid biofertilizer based on siderophores and siderophore-accompanying metabolites (SSAM) produced by Pseudomonas sp. ANT_H12B and formulated with molasses as an organic carrier. Its effects on sweet basil (Ocimum basilicum L.) were evaluated by assessing plant growth, photosynthetic performance, lipid peroxidation, elemental composition, soil enzyme activities, and bacterial community structure using full-length 16S rRNA nanopore sequencing. Results The combined SSAM+molasses formulation significantly enhanced plant growth, increasing leaf dry biomass by nearly 180%, leaf number by more than 300%, and stem length by approximately 40–50% compared with untreated plants. Improved plant performance was accompanied by enhanced photosynthetic efficiency (Fv/FM) and a marked reduction in oxidative stress, as reflected by nearly 50% lower malondialdehyde (MDA) content compared with the molasses-only treatment. Although elemental analysis revealed no major disturbances in plant nutrient balance among treatments, soil supplementation with the combined formulation strongly affected rhizosphere functioning and microbiome composition. In particular, the SSAM+molasses treatment coincided with approximately 35–50% higher β-glucosidase and dehydrogenase activities and clear shifts in microbial community structure. Discussion These findings suggest that molasses-enriched siderophore metabolites may act as effective biostimulants by promoting plant growth and mitigating oxidative stress, partly through modulation of rhizosphere microbiome structure and function.

Bioprospecting osmotolerant phyllosphere bacteria: functional characterization and biotechnological application for enhanced nutrient use efficiency in solanum crops