The Effects of Protein-Rich Keratin Hydrolysates and Calcium Nanocomposites on the Growth of Amaranth

This study investigates the effects of protein-rich keratin hydrolysates and calcium nanoparticles derived from feather and hoof waste on the growth of Amaranth (Amaranthus spp.). The primary aim was to evaluate the potential of keratinolytic bacteria isolated from keratin dump site to degrade feather and hoof waste effectively and assess its suitability as a biofertilizer. Through this research, the efficiency and nutrient-release capacity of the biofertilizer were analyzed, aiming to provide a sustainable alternative to synthetic fertilizers in enhancing vegetable growth.
Samples of feathers, and hooves were collected, cleaned, and processed into keratin-rich powders for microbial utilization and biofertilizer production. Aquamicrobium defluvii, an isolated keratinolytic bacterium, was cultured in a nutrient medium optimized for keratin degradation. Feather and hoof hydrolysates were produced through fermentation, followed by the formulation of calcium nanocomposites from the produced hydrolysates with calcium nitrate. These biofertilizers were then tested on Amaranth in a controlled field experiment, with applications via foliar spray and soil drenching. Growth parameters, including plant height, leaf count, and chlorophyll content, were regularly measured to assess biofertilizer efficacy.
Results showed that feather hydrolysate (FH) treatments significantly enhanced plant growth metrics, including plant length, leaf number, and biomass, compared to the water control and closely matched the effects of synthetic NPK fertilizer in many respects. In particular, 100% FH promoted higher growth than water across all parameters and nearly matched NPK in terms of plant length and chlorophyll content. Hoof hydrolysate (HH), especially at 75% concentration, also improved leaf number more effectively than NPK and substantially increased plant height and biomass compared to the water control, though it was slightly less effective than NPK overall in chlorophyll content.
In conclusion, this study suggests that keratin hydrolysates and their nanocomposite formulations can serve as effective biofertilizers, with FH offering balanced growth promotion similar to NPK, and HH providing notable advantages in leaf production. These findings contribute to the development of sustainable agricultural practices by utilizing waste-derived nutrients, potentially reducing dependency on synthetic fertilizers and promoting organic waste recycling in agriculture.