FEATHER DEGRADING FUNGI: ISOLATION, IDENTIFICATION AND MEASURING THE PROTEOLYTIC ACTIVITY USING SOLID-STATE FERMENTATION TECHNIQUE

Abstract

The rapid growth of the poultry industry has been associated with an increase in the production of keratin-containing residues (feathers are most abundant). Keratinolytic microorganisms have become biotechnologically important since they target the hydrolysis of highly rigid keratin. The main aim of the recent study was to isolate Aspergilli that have a keratinolytic activity. The keratinolytic fungi were isolated from three different places containing keratinous wastes. For cultivating these organisms, a solid-state fermentation (SSF) media was used containing feather as the only source of carbon and nitrogen. Then, we used Potato dextrose agar (PDA) media for purification and identification of isolates, by studying their culture and microscopic characteristics. Based on our results, we obtained four keratinolytic fungal species; namely, Aspergillus terreus, Aspergillus nidulans, Aspergillus niger , and Aspergillus fumigatus . The total protein content in the fermented media was measured using the method of Lowry. The hydrolysis of feathers by fungi resulted high amount of soluble protein from the insoluble hard keratin presented in chicken feather, which can be used as an organic fertilizer or as an ingredient in animal feed, reducing the environmental impact of feather waste from the chicken industry. This study highlights the feather-degrading fungi that are useful as biotechnological solutions, in the management of keratinous waste by using environmentally friendly methods.