Introduction
Agri Biochem Research Lab is exploring diverse ecosystems to unravel robust plant growth-promoting microorganisms for eco-friendly agriculture. A systematic research approach for isolation and building a proprietary culture bank.
Coal mining has been a vital part of India’s industrial growth, but it comes with environmental challenges, including soil contamination with heavy metals and alterations in pH levels due to the release of pollutants. However, nature always finds a way to restore balance, and in this study, researchers set out to explore the potential of plant growth promoting rhizobacteria (PGPR) in the rhizosphere of plants growing in hostile condition of coal mines in Gujarat, India. These PGPRs which are capable of adapting and support plant growth in adverse climate conditions can be invaluable assets for reclamation and restoration efforts, due to its unconventional nature to enhance plant growth and combat abiotic stress conditions.
Methods
Our team of researchers had collected 37 soil samples from the rhizosphere of plants in Amod G-19 Extension Lignite Mine in Gujarat (GMDC). To assess the physicochemical characteristics of the coal mine spoils, standard protocols from the Agri Biochem Research Lab were employed. The results indicated contamination with heavy metals, salt stress, and variations in pH levels, posing significant challenges to plant growth in the area.
Isolation and Characterization of PGPR
From the soil samples, the researchers isolated and characterized the PGPR. These microorganisms were found to possess multiple plant growth promoting traits, including nitrogen fixation, phosphate, potash, and zinc solubilization. A total of 89 isolates were selected for further detailed study.
Microbial Population and Phylogenetic Analysis
Among the isolated PGPR, the highest microbial population was observed for nitrogen-fixing bacteria, constituting 60.67% of the isolates, followed by phosphate-solubilizing bacteria at 21.35%, zinc-solubilizing bacteria at 14.60%, and potash-solubilizing bacteria at 3.37%. Further identification of the isolates was done through 16S rRNA gene sequencing. The phylogenetic analysis revealed that the PGPR belonged to three major phyla: Proteobacteria, Actinobacteria, and Firmicutes, with the Enterobacteriaceae family being the most represented genera.
Application in Reclamation and Stress Mitigation
These findings hold tremendous promise for reclamation efforts in coal mine spoils. The isolated rhizobacterial strains, with their ability to promote plant growth and counteract abiotic stress, present themselves as suitable bioinoculants for restoring the soil and supporting vegetation in the mining areas. By harnessing the natural potential of these PGPR, it might be possible to create more sustainable agricultural lands in coal mining regions, leading to the revitalization of the ecosystem.
Conclusion
The study highlights the importance of exploring nature’s hidden treasures even in seemingly challenging environments like coal mines. Plant growth promoting rhizobacteria found in the rhizosphere of plants growing in coal mines have exhibited various beneficial traits, making them potential bioinoculants for soil reclamation and stress mitigation. As environmental concerns continue to grow, understanding and utilizing such natural solutions become crucial for restoring balance and ensuring a sustainable future. Further research and implementation of these PGPR strains in reclamation projects can significantly contribute to environmental restoration efforts in coal mining regions, ultimately fostering a healthier and more resilient ecosystem.