Abstract
Valorizing chicken feather agro-wastes nowadays is imperative, if these wastes are disposed of without treatment, they could contribute to environmental problems. Conventional methods of processing chicken feathers such as landfilling, chemical treatment and burning are costly, non-time consumable and are toxic to the environment. Microbial hydrolysis, on the contrary, is now considered the main environmental-friendly recycling alternative. Hence, the aim of this study is to isolate keratinolytic bacteria with efficient feather hydrolysis, to optimize some of the physical parameters that could affect both bacterial growth and consequently its degrading ability. Results demonstrated an efficient feather degrading ability of newly identified Bacillus sp. D4 strain isolated from chicken feathers under optimal mesophilic temperature 37°C, pH 8.0 and 106 CFU/mL cell size inoculum, interpreted by highest keratin activity (55.0 ± 1.35 U/mL) and (54.3 ± 1.5 U/mL) respectively and higher total protein content in the cell free supernatant of 0.65 mg/mL. Beyond these parameters values, a moderate enzyme activity was observed at 40°C (35.1 ± 2 U/mL), 25°C (30.1 ± 2 U/mL), similarly at the initial pH 7.5 (52.3 ± 2 U/mL), pH 9.0 (49.0 ± 1.2 U/mL) and pH 10.0 (38.2 ± 1.35 U/mL). Bacillus sp. D4, on the other hand, was not able to tolerate high alkaline pH value 11.0 nor acidic pH 4.0 and 5.0 and high temperature of 55°C, correspondingly low enzyme activity was noted (19.0 ± 1 U/mL).
Highlights
Sustainable consumption and production promote the building of a green economy, quality of life, and long-term recovery for the planet
Pillai et al [17] isolated a serine protease from Bacillus subtilis P13 with reductase and keratinase activities capable of decomposing feathers. He et al [18] indicated the presence of 4 enzymes isolated from Bacillus subtilis involved in keratin hydrolysis. All these findings indicated that keratin degradation can be done successfully with microorganisms; the aim of many researchers recently is to implement the microbial conversion of feathers into value-added products in most poultry companies
The bacterial isolate with the highest clear zone measured in mm was considered as the most effective degrading isolate and was selected for further keratinolytic analysis, where it was cultured in 500 mL liquid feather medium (FM) composed of the following (w/v): 0. 5 g MgSO4, 0.05 g KH2PO4, 0.005 g FeSO4, 0.05 g CaCl2 0.25 g yeast extract and 5.0 g of washed chicken feathers (CF)
Summary
Sustainable consumption and production promote the building of a green economy, quality of life, and long-term recovery for the planet. Sustainable development has criminalized this unsustainable behavior and made unsustainable production and consumption patterns more sustainable. This ensures sustainable returns with positive effects for both the environment and individuals, modeling a green development strategy that transforms the concept of linear production and consumption into circular production and consumption. Working in a closed-loop, this strategy renders a product’s waste raw materials recycle able with innovative technology, resulting in economically valuable materials that contribute to the improvement of the local economy and the elimination of unemployment while simultaneously ensuring zero pollution [1].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
