Preparation Of Alternative Antibiotics Feed Additive Based Attapulgite And Study On The Antimicrobial Properties

With the wide application of antibiotics in livestock farming and even abuse,a series of severe issues including bacterial resistance and environmental pollution have attracted numerous attentions.When antibiotics are used in large quantities,some of them are left in animal feces during the metabolic process of livestock and poultry,and released into the soil ecosystem through feces,which will result in environmental pollution.On the other hand,residues of antibiotics in animal products can be transmitted to human beings through the food chain,thus threatening human health.Furthermore,mycotoxins could be produced in the process of feed storage,which has great harm to the production of livestock and poultry.To reduce or replace antibiotics in animal breeding and reduce the harm of mycotoxins,we need to find a type of antibacterial drug that can replace traditional antibiotics,developing a green safety antibiotics feed additive with cost inexpensive,good antibacterial activity,and inhibit mycotoxin.Based on attapulgite（ATP）,this paper analyzes whether it can meet the trace elements required by livestock and poultry,and combines cecropin and phillyrin to prepare a kind of green antibiotics feed additive using attapulgite as a substrate to replace antibiotics.The antimicrobial activity of attapulgite feed additive to Gram-negative bacteria and Gram-positive bacteria was studied,as well as its adsorption to mycotoxin was also studied.（1）The results of XRD and EDS showed that attapulgite was of high grade and contained trace elements such as Mg,Al,and Fe needed for livestock feed,and the heavy metal content of attapulgite met the limitation of the feed grade standard of China.Making the two new feed additives（K₁-ATP and K₂-ATP）by using attapulgite as a carrier,the antimicrobial peptides were loaded onto attapulgite by ball milling,wet dispersing,and freeze-drying technologies.The structure and morphology of the materials were analyzed by FT-IR,XRD,TG,SEM,and BET,and their antibacterial activities and mycotoxin adsorption performance were studied.The results showed that K₂-ATP prepared by wet dispersion and freeze-drying was more uniform and had a better structure.Antibacterial experiments showed that K₂-ATP had almost no inhibitory effect on Escherichia coli（E.coli）,but had an effect on Staphylococcus aureus（S.aureus）when the concentration was 5mg/m L.K₂-ATP has a certain adsorption effect on aflatoxin B₁ and zearalenone.（2）A green feed additive（FSE-ATP）was prepared by wet dispersion method and freeze-drying by loading phillyrin（FSE）into attapulgite which acted as a carrier.The microstructure,antibacterial activity,and adsorption capacity of FSE-ATP feed additive were systematically characterized and studied.The results of the antibacterial test and Gram staining showed that5mg/m L FSE-ATP had a strong inhibitory effect on S.aureus and E.coli.In addition,the feed additive of FSE-ATP has a certain adsorption effect on aflatoxin B₁,the adsorption process follows the Freundlich model and the quasi-second-order kinetic model.（3）The antibacterial peptide and phillyrin were loaded onto the surface of ATP,and a new green antibiotic feed additive（KFSE-ATP）was prepared by wet dispersion and freeze-drying.The microstructure,antibacterial activity,and adsorption properties of KFSE-ATP were systematically characterized and studied.SEM,XRD,and FT-IR showed that phillyrin bonded with antibacterial peptides and adsorbed on the surface of the attapulgite.The results of the antibacterial performance showed that KFSE-ATP had higher antibacterial activity than that of ATP,and had an inhibitory effect on E.coli and S.aureus at 5 mg/m L.In addition,the new feed additive of KFSE-ATP has a certain adsorption effect on aflatoxin B₁.,the adsorption process follows the Freundlich model and the quasi-second-order kinetic model.