Feather Keratin Hydrolysis by an Aquatic Bacterium Meiothermus I40 from Hot Spring Water

• Published in: International journal of food engineering Vol. 7; no. 2
• Main Authors: Yang, Jing-Iong, Kuo, Jen-Min, Chen, Wen-Ming, Ke, Huei-Jing, Chou, Yi-Ju
• Format: Journal Article
• Language: English
• Published: De Gruyter 01.01.2011
• Subjects: amino acids; bacteria; biodegradation; chickens; feather degradation; feathers; hot springs; hydrolysates; hydrolysis; keratin; keratinase; Meiothermus; optimization; Plackett-Burman; response surface methodology; screening; submerged fermentation; temperature; wastes; water; yeast extract
• ISSN: 1556-3758; 1556-3758
• DOI: 10.2202/1556-3758.2201

After undergoing keratinase digestion, feather wastes could have a great potential as a source of proteins and amino acids for many applications. In this study, the fermentation conditions of feather-degrading Meiothermus sp. strain I40 (I40) were optimized to enhance the biodegradation of chicken feather to hydrolysates. Initially, the factors essential for I40 keratinase production in submerged fermentation were screened, whereas response surface methodology (RSM) was then employed to evaluate the interactions among the effective factors. At first stage, eight fermentation parameters were screened using a Plackett-Burman (PB) design. Four effective factors identified by PB screening, namely feather concentration, tryptone concentration, yeast extract concentration, and incubation temperature, were further investigated their effects on keratinase production by RSM using central composite design (CCD). The I40 fermentation conditions for maximal keratinase activity were as follows: tryptone concentration 0.16 percent (w/v), yeast extract concentration 0.27 percent (w/v), feather concentration 0.08 percent (w/v), and incubation temperature at 51.7°C for 72 hr under 120 rev/min shaking. Compared to the initial stage, a 13.3-fold increase in keratinase activity was achieved when I40 incubated in the optimized conditions.