Valorization of Chicken Feather Waste for Concomitant Production of Keratinase, Oligopeptides and Essential Amino Acids Under Submerged Fermentation by Paenibacillus woosongensis TKB2

Response surface methodology was employed to optimize and improve submerged fermentation for the production of keratinase by Paenibacillus woosongensis TKB2. Among different physico-chemical parameters, 0.8 % chicken feather (w/v), 2.36 % bacterial inoculum (v/v), 5.08 % NaCl (w/v) and 0.052 % K2HPO4 (w/v) were significantly influencing on keratinase production, feather degradation ability and oligopeptides production, analysed through Plackett-Bruman factorial design followed by Box-Behnken response surface methodology. Under these conditions keratinase activity (78.62 U ml(-1)), feather degradation efficiency (86.99 %) and oligopeptides production (3.77 mg ml(-1)) respectively, were obtained in submerged condition. Furior tranansform infrared spectroscopy and scanning electron microscopy reveled the sulphitolysis and keratinolysis of feathers. After fermentation culture filtrate containing significant amount of oligopeptides were analysed through reduced gel electrophoresis and Matrix-assisted laser desorption ionization mass spectrometry-time-of-flight (MALDI-TOF), reveled that the molecular masses of the solubilized products, oligopeptides, were less than 8,000 Da. Amino acids were detected and analysed through thin layer chromatography and high performance liquid chromatography signifies that a rich number of essential amino acids (valine, lycine, alanine, isoleucine, cysteine, tryptophan, lysine, glutamic acid, arginine, histidine, glycine, aspartic acid, thionine, hydroxyproline and serine) were produced in the fermented medium. This results influence the bioactivities of oligopeptides and amino acids derived from the bacterial-degradation of chicken feathers may be used for livestock feedstuffs formulation and used as nitrogen supplementation for micriobial growth medium.