Simultaneous production of proteases and antioxidant compounds from agro-industrial by-products

•Different bioproducts was obtained simultaneously using different by-products.•Integrated process was enabled to obtain proteolytic and keratinolytic enzymes.•Residual biomass provided the highest protease activity (1306.6 U/mL) at 32-h.•The reused feather meal reached the highest keratinolytic activity (89 U/mL) at 32-h.•Hydrolysates produced in cultivation have great potential as natural antioxidants.

The use of processes for simultaneous production of bioproducts as enzymes and bioactive compounds is an interesting alternative to reduce environmental impacts. Thus, the aim of this study was to produce simultaneously, using the biorefinery concept, both proteases and bioactive compounds with antioxidant activity from Bacillus sp. P45 cultivation by using different by-products. The integrated process developed in this study enabled to obtain enzymes with proteolytic and keratinolytic properties in a process with alternate substrates from agro-industrial by-products (feather meal, residual feather meal and biomass), thus, creating an interesting alternative to managing them. The residual biomass provided the highest protease activity (1306.6 U/mL) and the reused feather meal reached the highest keratinolytic activity (89 U/mL), both at 32 h of cultivation. Moreover, hydrolysates produced in cultivation using feather meal and residual biomass had high antioxidant activity, they have great potential as natural antioxidants.