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Wool‐waste valorization: production of protein hydrolysate with high antioxidative potential by fermentation with a new keratinolytic bacterium, B acillus pumilus A1
Author(s) -
Fakhfakh N.,
Ktari N.,
Siala R.,
Nasri M.
Publication year - 2013
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12246
Subject(s) - bacillus pumilus , hydrolysate , dpph , food science , wool , chemistry , antioxidant , fermentation , mesophile , bacteria , biochemistry , biology , hydrolysis , materials science , genetics , composite material
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 B acillus 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 IC 50 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.