Influence of Trichoderma asperellum and Bacillus subtilis as biocontrol and plant growth promoting agents on soil microbiota

Cyanobacterium Nostoc species mitigate soybean cyst nematode infection on soybean by shaping rhizosphere microbiota

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most devastating and yield-limiting pathogen that threatens soybean production globally. Sustainable SCN disease management strategies are needed. In this study, a cyanobacterial strain was isolated from SCN-infected soybean soil and identified as Nostoc punctiforme using the cyanobacterial 16S rRNA gene sequence. When susceptible soybean plants were grown in the SCN-inoculated soil, N. punctiforme inoculants significantly reduced the total number of SCN eggs and second-stage juveniles (J2s), compared to the control with SCN inoculation only. Further microbial analysis showed that N. punctiforme inoculants changed the bacterial and fungal communities in the soybean rhizospheres and significantly increased the relative abundance of several bacterial and fungal species with potential nematicidal activities, suggesting the changes of soybean rhizosphere microbiota may partially contribute to the activity of N. punctiforme inoculants against SCN. However, N. punctiforme inoculants did not directly induce soybean defense reactions against SCN. Thus, N. punctiforme may be a potential microbial source against SCN invasion in soybean.

Effects of biopreparations based on Bacillus and Trichoderma, combined with mineral and organic fertilization and a Pisum sativum L. forecrop on improving the tolerance of Maize plants to drought stress

The increased frequency of extreme weather phenomena, such as heat waves and drought, adversely affects the condition of plants. The need to strive for more sustainable methods of growing plants requires undertaking researches that focus on strengthening the immunity of plants using methods that have a positive impact on both crops and the natural environment. The aim of the study was to assess the effectiveness and compare the effects of selected microbiological preparations based on Bacillus bacteria and Trichoderma symbiotic fungi, combined with mineral (NPK) and organic fertilization (manure) and a Pisum sativum L. forecrop on improving the tolerance of maize plants to drought stress. The pot experiment was carried in 2023 as a two-factor experiment in three replicates. Physiological parameters were assessed based on measurements of photosynthetic efficiency (A - CO2 assimilation rate, E - Transpiration Rate, Gs - Stomatal Conductance) and chlorophyll content (CCI) and fluorescence (F0 - initial fluorescence, Fm - maximum fluorescence, Fv/Fm - maximum photochemical efficiency of PSII, Yield - quantum yield of the photochemical reaction in PSII, ETR - electron transport rate, NPQ - Non - Photo-chemical Quenching), as well as soil respiration (NCER- Net CO2 Exchange Rate, W flux- Net H2O Exchange Rate, Ce- Soil Respiration) and biometric measurements (dry mass of shoots and roots).The measurement of photosynthesis efficiency under drought stress clearly indicated the highest, significant effect caused by Trichoderma preparation with both fertilizers. In the control, CO2 assimilation was practically inhibited due to drought (98% drop), while in the plants in which the Trichoderma preparation was used together with half dose of NPK and manure, there was only a slight decrease (1% and 13% respectively). A greatest, significant improvement in the DM of roots under drought was noted in plants in which the Pisum forecrop was applied together with NPK and manure (230% and 168% respectively). Pisum forecrop and treatments with microbiological preparation containing Trichoderma, make it possible to reduce the fertilization dose by at least half. This is particularly important in view of the global trend of increasing drought stress and efforts to improve soil quality.

Deciphering the microbiome dynamics in an effective banana Fusarium wilt biocontrol interaction system

This study explored the effects of bacterial and fungal biocontrol agents (consortia) on the microbiome of Fusarium wilt (Foc TR4)-infected Cavandish banana soils in terms of alteration of prevalence and abundance. The results showed a significant shift in microbial diversity, dominance, abundance, evenness, richness and composition core and indicator microbiome in response to soil applied consortia and untreated controls. A total of 2857 bacterial OTUs from 331 families across 40 phyla dominated with Bacillaceae (40.2%), Acidobacteriaceae (14.2%), Haloarculaceae (12.6%), and Paenibacillaceae (9.4%). There were 4,868 fungal OTUs from 520 families across 18 phyla dominant with Mortierellaceae (20.9%), Cortinariaceae (7.6%), Aspergillaceae (6.2%), Pandeidae (5.6%), and Pyronemataceae (5.0%). Alpha diversity analysis indicated that bacterial diversity varied across treatments where T2 has the highest OTUs, while fungal diversity remained relatively stable across the treatments. Beta diversity and PCoA analysis revealed the differences in community compositions across treatments in both bacterial and fungal microbiome. Bacterial communities in T3 and T5 were highly similar, whereas T4 had a notable difference in fungal communities. This study identified a total of 192 bacterial core OTUs dominated with Firmicutes, Proteobacteria, and Acidobacteriia. In the case of fungi, 59 core OTUs from Ascomycota, Basidiomycota, and Mucoromycota are the most abundant ones within the treatments. Venn diagram revealed unique, common and shared OTUs suggesting antagonistic interactions of the soil applied consortia. DESeq2 analysis revealed a significant shift of core microbiome, where positive fold changes in Betaproteobacteria for bacterial, and Fusarium sp. for fungi were noticeable. Heatmap analysis revealed the treatment-dependent differences in community composition where T2 has higher bacterial abundance and T4 has higher fungal abundance suggesting that the biocontrol treatments affect the soil microbiome differently depending on the combinations and the origins of the consortia. The indicator species analysis identified 37 bacterial and 34 fungal OTUs that were specific and indicative of particular treatments that suggest microbial consortia might be selectively enhancing the growth of functionally beneficial microbial populations of the soil that promote soil health and disease suppressiveness. This study recommends that the use of biocontrol agents in the form of consortia would not only expand the diversity of the soil microbiome but also improve the effectiveness and the sustainability of Fusarium wilt management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-025-04223-7.

Balancing Nature and Nurture: The Role of Biocontrol Agents in Shaping Plant Microbiomes for Sustainable Agriculture

Microbial communities in the plant environment are highly dynamic, with bacterial populations rapidly responding to changes. Numerous studies have examined how both inherent plant characteristics and environmental factors shape plant-associated microbiota. These factors determine which bacterial communities thrive and how they interact with plants; certain conditions favor beneficial bacteria, and others support pathogens. In this mini-review, we focus on an additional factor influencing plant microbiomes and their surrounding environments: the use of biocontrol agents. The increasing application of microbial inoculants and their metabolites as biocontrol strategies in agriculture has created a critical knowledge gap about the effects of introducing non-native bacterial species into natural plant ecosystems. The inoculation of plants and their environments with exogenous biocontrol microorganisms has the potential to alter microbial community diversity and composition, presenting both opportunities and challenges for sustainable agricultural practices.

Improving Soil Quality and Crop Yields Using Enhancing Sustainable Rice Straw Management Through Microbial Enzyme Treatments

This study develops a model to raise public awareness about the consequences of burning rice straw after harvest, including environmental pollution, soil degradation, and increased CO2 emissions that contribute to the greenhouse effect. The distinctive feature of the research is the introduction of a post-harvest rice straw treatment process using microbial products capable of secreting cellulase enzymes, which can break down the cellulose in the straw. This process shortens the decomposition time and produces natural organic fertilizer, thus reducing cultivation costs by 60% and increasing crop yields by 20%. The experimental model was carried out in Cam My district, Dong Nai province, Vietnam, including 4 models: no microbial products; using Bio Decomposer; using NTT-01; and using NTT-02. Each experimental field had an area of 650 m². The results showed a significant reduction in straw decomposition time after 14 days of use of the products, with a decomposition rate of up to 80%, nearly twice as fast as without the products. This helps save time, produce natural organic fertilizers, reduce care costs, and increase rice yields, resulting in more income for local residents. These findings demonstrate the effectiveness of microbial treatments in sustainable agriculture and their potential for a broader application in the management of agricultural waste.

Synthesis and characterization of copper oxide nanoparticles: its influence on corn (Z. mays) and wheat (Triticum aestivum) plants by inoculation of Bacillus subtilis

Nanotechnology is now playing an emerging role in green synthesis in agriculture as nanoparticles (NPs) are used for various applications in plant growth and development. Copper is a plant micronutrient; the amount of copper oxide nanoparticles (CuONPs) in the soil determines whether it has positive or adverse effects. CuONPs can be used to grow corn and wheat plants by combining Bacillus subtilis. In this research, CuONPs were synthesized by precipitation method using different precursors such as sodium hydroxide (0.1 M) and copper nitrate (Cu(NO₃)₂) having 0.1 M concentration with a post-annealing method. The NPs were characterized through X-ray diffraction (XRD), scanning electron microscope (SEM), and ultraviolet (UV) visible spectroscopy. Bacillus subtilis is used as a potential growth promoter for microbial inoculation due to its prototrophic nature. The JAR experiment was conducted, and the growth parameter of corn (Z. mays) and wheat (Triticum aestivum) was recorded after 5 days. The lab assay evaluated the germination in JARs with and without microbial inoculation under CuONP stress at different concentrations (25 and 50 mg). The present study aimed to synthesize CuONPs and systematically investigate the particle size effects of copper (II) oxide (CuONPs) (< 50 nm) on Triticum aestivum and Z. mays. In our results, the XRD pattern of CuONPs at 500 °C calcination temperature with monoclinic phase is observed, with XRD peak intensity slightly increasing. The XRD patterns showed that the prepared CuONPs were extremely natural, crystal-like, and nano-shaped. We used Scherrer's formula to calculate the average size of the particle, indicated as 23 nm. The X-ray diffraction spectrum of synthesized materials and SEM analysis show that the particles of CuONPs were spherical in nature. The results revealed that the synthesized CuONPs combined with Bacillus subtilis used in a field study provided an excellent result, where growth parameters of Z. Mays and Triticum aestivum such as root length, shoot length, and plant biomass was improved as compared to the control group.