Actinomycetes: Potential Link to Sustainable Agriculture and Environment

Actinomycetes are spore-forming, aerobic bacteria that are gram-positive and possess high guanine-cytosine (57-75%) content in their DNA.They are belonging to Actinomycetales order, which is noted for the development of both substrate and aerial mycelium.These bacteria exhibit true aerial hyphae and have a filamentous structure, resembling fungi.They are among the most prevalent microorganisms found in soil, generating thread-like filaments that contribute to the "earthy" scent associated with freshly turned, healthy soil.Actinomycetes play crucial roles in the cycling of organic matter, suppressing the growth of various plant pathogens in the rhizosphere, and decomposing complex polymer mixtures found in deceased plant, animal, and fungal material, thereby producing many extracellular enzymes that enhance crop production.They significantly aid in biological soil buffering and the biological regulation of soil environments through processes such as nitrogen fixation and the degradation of high molecular weight pollutants like hydrocarbons in contaminated soils.Besides this, actinomycetes can serve as biofertilizers in sustainable agriculture, as they enhance plant growth and soil health through multiple plant growth-promoting features, including the solubilization of phosphorus, potassium, and zinc, the generation of Fe-chelating compounds, production of phytohormones like indole acetic acids, cytokinins, and gibberellins, as well as biological nitrogen fixation.Moreover, actinomycetes do not harm the environment; rather, they bolster long-term soil health by creating and stabilizing compost piles, forming stable humus, and partnering with other soil microorganisms to decompose resistant plant and animal residues, thus preserving the soil's biotic balance by collaborating with nutrient cycling.