Study On Screening Of Feather Degrading Strain And Mixed Liquid State Fermentation

As a result of the rapid development of animal husbandry the protein demand of our country increases year by year. Because of the shortage of protein resource our country mainly import fish powder. For this reason, developing new protein resource comes to be a hot spot. Our country has rich feather resources whose annual production is hundreds of thousand tons. Rejection of these feather causes huge wastes and pollutions.Birds feather has very high protein content, especially the cystine content which was the highest of all kinds of natural protein feeder. However birds feather is mainly made of ceratin which is quite stable because of the disulfide link between peptide chain. Digestibility of animal to untreated feather is very low. More and more attention is being paid to microbe fermentation to decrease energy use, to get more protein and animo acids, and to reduce environmental pollutions.All edaphon DNA was extracted in special environment and the DNA was set to be template in this experiment, use PCR-SSCP technology to analyze microbes species group in sample and get3stocks of PD bacterium of ceratin, NJQ1,NJQ2,NJQ3. By using the ways of morphology view, physiology determination and16SrRNA gene analysis, these3bacts were tested to be Enterococcus faecalis, Bacillus cereus, and Bacillus pumilus.The effect of monoxenie liquid state fermentation and mixed liquid state fermentation of NJQ1, NJQ2, NJQ3were analyzed and compared. The degradation rate of feather could be raised by changing temperature, pH, inoculation quantity, inoculation ratio, bacterium age, mineral salt, nitrogen and carbon sources. By the test data the best condition was confirmed:initial pH8.5, inoculation quantity6%, inoculation ratio of NJQ2:NJQ3as2:3, bacterium age12hours, K2HPO40.09g·L-1、KH2PO40.36g·L-1、NaCl0.3g·L-1、bacterium,37℃,180r·min-1shake culture48h. The best cultivating condition was found during the research. Deep brown turbid fluid appeared during24-36h, feathers construction broke down obviously. When it came to the48th hour, nearly of the branchlets fell off and degrdn, only gross stick existed, the degradation rate reached72%.This experiment offerd highly efficient and stabled degradation backterium for feather keratin use. It optimized the condition of mixed liquid culture fermentation and made fermentation reaction faster and effective. Further more the product was also safe and reliable which could be a cheap and safe solution to the shortage of animal’s feeder protein.