Studying On Isolation And Cultivation Of Feather-degrading Bacteria And Enzymatic Properties Of Proteins

Our poultry processing industry produce large amounts of waste feathers each year, a huge amount of feathers accumulation create adverse impact on the environment. Making advantage of the abandoned feather and turning it into wealth is imperative research trends. The main component of feather is keratin, keratin is needed in animal feed, fertilizer and pharmaceutical industries. This paper aims to study the strain screened that can efficiently degrade feathers, further to optimize relevant culture conditions and explore its enzymatic characteristics of the enzyme produced. Providing an experimental basis and theoretical foundation for the fermentation process of the strains with biodegradation ability of waste feathers. The results are as follows:(1) Repeatedly screened efficient feather-degrading bacteria from the sample, obtained the optimal strain B2. In the screening medium at 30 ?, 150 r/min shaking culture for 2 d, the keratinase activity of this strain can reach 67.14 U/m L. Strain B2 has significant degradation ability on natural feathers. After training for 3 d the pinna all fall of the quill. After 4 d the feather degradation rate can reach 71.3 %.(2) The growth environment and nutritional conditions of strain B2 were optimized. After optimization, we obtained the environmental conditions suitable for strain B2 growth and for the production of keratinase: liquid volume 50 m L(250 m L Erlenmeyer flask), culture temperature is 30 ?, inoculum is 5 %, initial p H is 8.0. After optimization, the media component suitable for strain B2 growth and produce keratinase is: feather powder 15 g/L, K2HPO4 1.4 g/L, KH2PO4 0.7 g/L, Na Cl 0.5 g/L, Mg SO4 0.01 g/L, Ca Cl2 0.01 g/L, NH4NO3 1 g/L, distilled water to make up.(3) The strain B2 produced by the enzymatic properties Keratinase study, examining reaction temperature, p H, metal ions and chemical reagents B2 strains produced keratin crude enzyme activity in rats. Meanwhile, the Michaelis-Menten equation simulation curve analysis kinetic properties of the enzyme reaction.B2 strains produced keratinase suitable reaction temperature is 25 ?to 60 ?, p H of 7.0-8.0. The keratinase most suitable reaction temperature is 50 ?, under the temperature condition, the angle protease activity reached 333.14 U/m L. Optimum reaction p H of 8.0, at which p H, the keratinase activity was 312.01 U/m L.Reaction system, the metal ions Mg2+ and Ca2+ added strains B2 produced keratin crude enzyme has inspired action, and Zn2+ and Mn2+, Co2+, Cu2+, Hg2+ and Fe2+ is the angle of the protease inhibitor.Reaction system, the addition of chemical reagents DMSO, B2 strains produced keratin crude enzyme has inspired action, and Tween-80, EDTA and SDS to the corner protease inhibition.Properties of the enzyme kinetics of strain B2 produced keratinase conducted through Michaelis-Menten equation to get fit straight double reciprocal method, the equation for Y=0.0017X+0.0057, linear correlation coefficient R2=0.9900, this formula Km value of the enzyme calculated 0.30 mg/m L, Vmax is 175.44 A280·m L-1·h-1.