Microbial Bioactives | Online ISSN 2209-2161
Volume 8 Number 1 2025
REVIEWS (Open Access)
Microbial Allies in the Soil: How Probiotic Microbes Transform Nitrogen Fixation for a Sustainable Agricultural Future
Grace E. Li 1 *, Aroha T. Ngata 2, Farah S. Yusuf 3
Microbial Bioactives 8 (1) 1-8 https://doi.org/10.25163/microbbioacts.8110466
Submitted: 12 July 2025 Revised: 01 September 2025 Accepted: 07 September 2025 Published: 08 September 2025
Abstract
Nitrogen is a fundamental element for plant development, yet its availability in agricultural soils remains a persistent limitation. Conventional nitrogen fertilizers, though effective in boosting yields, have led to environmental challenges such as eutrophication, soil degradation, and greenhouse gas emissions. To address these issues, biological nitrogen fixation (BNF)—a natural process driven by beneficial microbes—offers an eco-friendly and economically viable alternative. This review synthesizes recent advances in understanding how probiotic microorganisms, particularly plant growth-promoting rhizobacteria (PGPR) and diazotrophic bacteria, contribute to nitrogen fixation and sustainable soil fertility.The study first explores the diversity and ecological roles of nitrogen-fixing bacteria such as Rhizobium, Azospirillum, and Azotobacter, focusing on their symbiotic and associative interactions with plants. Methods for studying nitrogenase enzyme activity and microbial colonization dynamics are also discussed. Findings highlight how probiotic-assisted nitrogen fixation enhances nutrient uptake, stimulates root growth, and improves plant resilience under abiotic stress conditions. Moreover, the integration of probiotics reduces the dependency on synthetic fertilizers, thereby supporting long-term soil health and environmental balance.However, challenges remain—particularly in ensuring microbial survival, adaptability to varied soil conditions, and competitiveness with indigenous microflora. Emerging biotechnological approaches, including genetic engineering and microbial consortia design, hold promise for enhancing nitrogen-fixing efficiency. In conclusion, the strategic use of probiotics in agriculture presents a sustainable pathway for optimizing nitrogen management while promoting ecological harmony and food security.
Keywords: Probiotics; Biological nitrogen fixation; Diazotrophic bacteria; Sustainable agriculture; Soil fertility
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