Multifunctional Actinomycetes: Harnessing Bioactive Metabolites for Innovative Therapeutics and Agricultural Solutions

The global search for novel bioactive metabolites has intensified interest in actinobacteria due to their pharmaceutical and biotechnological potential. This study presents an integrative screening strategy that combines comprehensive biological assays, phytochemical profiling, therapeutic evaluation, and agricultural application. Seventeen actinobacterial isolates were systematically assessed through antioxidant (FRAP, DPPH, SOS, XO inhibition), anti-hemolytic, anti-lipid peroxidation, cytotoxicity, oxidative stress markers, and antimicrobial tests to identify multifunctional strains. Three top-performing isolates were further examined for phenolic acids, flavonoids, and their anticancer, anti-inflammatory, and anti-cholesterol properties. Isolate 17 exhibited the highest activity and was identified as Plantactinospora endophytica JTT05 based on 16S rRNA sequencing and phylogenetic analysis. Importantly, we report for the first time that this potent isolate not only displays strong therapeutic bioactivities but also promotes plant development. When applied to Eruca sativa, P. endophytica JTT05 enhanced fresh weight by 3.14%, dry weight by 24.75%, photosynthetic efficiency by 13.46%, and improved phytochemical contents including phenolics (+12.31%), flavonoids (+0.73%), antioxidants (+4.80%), and glucosinolates (+22.21%). Overall, P. endophytica JTT05 emerges as an innovative dual-function microorganism, offering promising antioxidant, anticancer, anti-inflammatory, and anti-cholesterol activities while simultaneously serving as a sustainable plant growth–promoting agent.