Unveiling the advanced application of actinomycetes in biotic stress management for sustainable agriculture

Actinomycetes are gram-positive, filamentous bacteria that are a major source of bioactive compounds and secondary metabolites. These organisms play a major role in organic farming and sustainable agriculture due to their diverse features including plant growth promotion, enhanced soil nutrients through phosphate solubilization and biocontrol properties of their metabolites like polyketides and β-lactams. Recent time, there has been an increased interest in using actinomycetes as a substitute for pesticides and chemical fertilizers to avoid adverse phenomena such as bioaccumulation, biomagnification, soil degradation etc. This review sheds light on the taxonomy and classification of actinomycetes, their morphological and biochemical characteristics and their relevance to insect pests. It further explores their role as biopesticides, biofertilizer and plant growth promoter due to the broad-spectrum action of their secondary metabolites. For instance, Streptomyces lydicus can produce some metabolites and lytic enzymes that protect the crop from insect pests, while Streptomyces avermitilis synthesizes a compound called avermectins which are toxic to insect pests. Additionally, presented the current advancements in the use of actinomycetes as biopesticides including the incorporation of genetic engineering and nanotechnology. Eventually discussed the research gaps and future prospects in this field for sustainable crop protection. With the agricultural sector moving towards sustainable solutions, actinomycetes have emerged as a promising, eco-friendly alternative, contributing to higher crop yields and more effective biotic stress (crop pests and diseases) management.