"Synthesis, Characterization, and Agricultural Applications of Biodegradable Polymers from Renewable Resources"

The rapid development of biodegradable polymers, particularly the potassium salt of polyglutamic acid (PGA-K), has gained significant attention due to growing environmental concerns over synthetic plastics. This study synthesizes and characterizes PGA-K derived from soil-isolated Bacillus species, assessing its properties and potential applications in drug delivery, agriculture, and environmental management. Comprehensive characterization techniques, including Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and UV-Vis spectroscopy, confirm the structural integrity and functional groups of PGA-K. The antimicrobial efficacy of PGA-K was evaluated against various bacterial strains and yeast species, demonstrating substantial antibacterial activity, especially against Pseudomonas aeruginosa (21 mm inhibition zone), and notable antifungal activity against Saccharomyces cerevisiae (18 mm inhibition zone). Additionally, the cytotoxicity of PGA-K was investigated using brine shrimp, revealing an LD50 of 49 ppm, indicating moderate toxicity that necessitates careful application considerations. These findings suggest that while PGA-K presents promising applications as a biodegradable alternative, its ecological impacts must be addressed to ensure environmental safety.