The Scale Of The Preparation Of Antimicrobial Peptides Feed Additive And Its Application In Broiler Breeding

Currently,due to the abuse of antibiotics in breeding industry,food safety and other issues have caused widespread concern by consumers.Biological antimicrobial peptides have many advantages,such as antibacterial ability,broad antimicrobial spectrum,non-resistance,etc,therefore,antimicrobial peptides have become an alternative to antibiotics in animal-breeding industry.In this paper,the preparation technology of antibacterial peptide from B.laterosporus S62-9 was studied,and then it was applied to industrial preparation of antimicrobial peptide feed additive.Finally,the antimicrobial peptides feed additive was used to feed the broiler chickens.The main contents were as follows:1)Screening of materials for antimicrobial peptides adsorption and optimizing the adsorption process.Firstly,inorganic zeolite powder was screened as the optimal adsorption materials for antimicrobial peptides adsorption amongthe several cheap adsorption materials.Then,the adsorption conditions were optimized by the single factor experiment and the results showed the optimal temperature was 50℃,p H value was 8.0,zeolite powder adding amount was 3%(m/v)and the adsorbing time was 2 h.On this basis,the condition of temperature,p H value and zeolite powder adding amount were farther optimized by response surface experiments.The best adsorption conditions for antimicrobial peptides adsorption were 60℃,p H 8 and adding 4%(m/v),and the adsorption rate could reach95%.2)Studing on the mechanism and product characteristics of zeolite adsorbing antibacterial peptide.The process of zeolite adsorbent antimicrobial peptides were fitted by isotherm model and kinetic equation,and the results showed Langmuir adsorption isotherm model,Redlich-Peterson adsorption isotherm models and pseudo second order equation were the suitable fitting models.After incubating in 100℃ for 120 min,antibacterial activity loss of the composit of antimicrobial peptides-zeolite was small,so it had high thermal stability.When the p H value was between 2.0 to 11.0,the loss rate of the antibacterial activity was between 10% to 15%.It still had high antibacterial activity,high acid and alkali stability.The intestinal enzyme action experiment found that pepsin,lipase and cellulase had little influence in the antibacterial activity of the product,and it had high stability towards intestinal enzyme.Over 10 weeks at room temperature and frozen,products under both conditions have strong antibacterial activity,and the inhibition zone diameter was under0.08 mm.Therefore,the composit of antimicrobial peptides–zeolite could maintain for long time with high antibacterial activity and high stability.3)Researching on industrial preparation technology of antimicrobial peptides feed additive.Through a series of improved preparation process,a set of integrally industrial production process was formed for the prepatation of antimicrobial peptides feed additive.After fermentation,the fermentation broth was sterilized 10-15 min at 121℃.Fisrtly,4%-5% zeolite powder was added to the Sterilizing fermented liquid,then the antimicrobial peptides adsorption was carried out at 50℃-60℃ for 2 h,the fermentation broth was filtered and the zeolite was collected next.andlastly,the composite was dried and packaged.The industrial product of antimicrobial peptide feed additive was obtained and showed obviously antibacterial effect.4)Studing on "no resistance" breeding of broiler chicken with antimicrobial peptide feed additive.The antimicrobial peptides feed additive product was applied in breeding of broiler chickens.The feed conversion rate and death rate of the test group was lower than blank group,and slaughtering rate was higher than the blank group,and high dose group of them was most obvious.The results showed the antimicrobial peptide feed additive could improve the growth performance and the body immunity of broiler chickens.