| As encrusted protein , keratin has the characteristics of no-dissolve , anti-decomposition and antipain, and it also cannot be dissolved in nomal conditions. So keratin is very difficult to be delt with. And at the same time a lot of keratin materials are released in China, but they have not been used properly. With the rapid development of stockbreeding and amino acid industry, the demand of protein resource is increasing these years. So it is very necessary to research effective methods to make waste feather convert to protein and mixing amino acid and to make it to be used directly or to be the cheap resources for the purify of amino acid. By doing this we can turn wastes to treasures and protect our environment and make full use of the resources.The following things were studied for the reuse of feather wastes:1, The study of chemical hydrolysis on feather keratinThe optimum hydrolytic conditions were specified by studying the effects of medium concentration, the proportion of solid and liquid, the reaction time, the reaction temperature. And the dynamics analysis was done under this condition. It showed that the yield was higher in H2SO4 than in NaOH. But anyway there were many problems in chemical method, such as high energy and material consumption, high pollution and equipment erosion.2, The isolational screening and identification of feather-degrading microorganismsSix strains of bacteria(L1, L2, L3, L4, L5, L6) with high activity for feather-degradation were isolated from soils, strain L1 of which showed the highest activity of feather degradation based on the contrastive experiment. And after observing the shape feature and sequencing the 16SrRNA, strain L1 was identified and named as Stenotrophomonas maltophilia DHHJ temporarily in our college. Stenotrophomonas maltophilia was found for the first time to be able to degrade feather. And strain L1 could make the integrated feather fibres breakdown afterincubated for one day. The feather was completely disintegrated by strain LI after incubation for five days, and the calamus was degraded partially. The degrading rate reached 86.6% and the maximum of protein content reached 23.88 mg/mL after six days. All of these results indicated that strain LI possessed the stronger capacity of degrading feather keratin.3 n The study on zymolytic condition of strain DHHJThe optimum zymolytic culture medium of strain DHHJ was obtained after the optimizing experiment: glucose lg, feather powder 2.5g, casein 0.2g, KC1 0.0373g, NaCl 0.0294g, Tween80 0.4g, Na2HPO4: KH2PO4=0.4:0.03, pH7.5. The optimum zymolytic condition is at 40°C and at 48h with loading 25ml/250ml. And under this condition the keratinase production abilities and feather degradation abilities of strain DHHJ were much better under the optimized zymolytic condition than unoptimizable zymolytic condition.The conditions of hydrolyzing feather by using strain DHHJ and other proteinases were studied by orthogonal test. It showed that the initiative optimized hydrolytic method was to react 12h with 100 mg/ml papain PS] continuously after hydrolyzing feather 48h by strain DHHJ under the optimized zymolytic condition. It was proved that using this hydrolytic method was more effective. In future the indepth studied on this should be done.Chen Li (Environmental Engineering) Supervised by Professor Zhou Mei Hua...
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