Related Experiment Video
Updated: May 11, 2026

Methods for Facilitating Microbial Growth on Pulp Mill Waste Streams and Characterization of the Biodegradation Potential of Cultured Microbes
Published on: December 12, 2013
Wool-waste valorization: production of protein hydrolysate with high antioxidative potential by fermentation with a
1Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, Sfax, Tunisia. nahedfakh_zouari@yahoo.fr
Aims:
Wool, a recalcitrant waste mainly composed of keratin, constituted a serious problem for the environment and was not effectively valorized. This study reported the optimization of wool-waste biodegradation by a new keratinolytic bacterium Bacillus pumilus A1. The in vitro digestibility and the antioxidant potential of wool protein hydrolysate (WPH) were also investigated.
Methods And Results:
The antioxidant potential of WPH was evaluated using in vitro antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power and metal (Fe(2+)) chelating activity. Cultivation on 50 g l(-1) of wool for 2 days, at 45°C and at initial pH of 10, resulted in maximum production of amino acids and peptides (39.7 g l(-1)). WPH presented a very high in vitro digestibility (97%) as compared with that of the untreated wool (3%).
Conclusions:
The keratin present into the wool-waste was completely solubilized. Interestingly, WPH presented an important DPPH radical-scavenging activity with an IC50 value of 0.14 ± 0.01 mg ml(-1).
Significance And Impact Of Study:
WPH would be a very useful source of protein and antioxidants in animals' diets.
Related Concept Videos
Production of Organic Acids
Microbes in the Production of Fermented Foods
Microbes in Food Production
Biofuels
Microbial Bioremediation of Plastics
Production of Antibiotics
