The study of the antibacterial effect of peptides obtained fromthe microbial degradation of feather by Bacillus Tequilensis BK۲۰۶

Background and Aim : Feather is one of the most important byproducts of the poultry industry.۹۰% of the feather proportion are filamentous protein structures called beta-keratin, which has asolid figure due to the presence of a high amount of cysteine and can only decompose by keratinaseenzyme, which is an extracellular protease and has the ability to cut disulfide bonds. These featherhydrolysates can be used in various industries. The aim of this research is to investigate theantibacterial effect of peptides obtained from the microbial degradation of the feather by BacillusTequilensis BK۲۰۶Methods : B. Tequilensis was cultured in feather medium, after complete degradation of thefeathers, the culture medium containing the hydrolyzed proteins was spray dried. In order toqualitatively measure the antibacterial property, concentrations of ۵۰, ۱۰۰, and ۲۰۰ mg/ml of driedpeptides were prepared then were transferred to agar plates containing Escherichia coli andStaphylococcus aureus bacteria, after incubation the disc diffusion was checked. For quantitativemethod certain concentrations of the peptides were prepared in the ۹۶-well plate containing thementioned bacteria and the absorption was measured by ELISA reader then MIC (minimuminhibitory concentration) was calculated. To determine the minimum bactericidal concentration(MBC) of peptides, the concentrations in the ۹۶-well plate was inoculated in solid culture mediumalong with the bacteria.Results : qualitative analysis showed that the zone of inhibition were observed only in the S.aureus bacteria plate of all the mentioned concentrations, and the diameter of the zone increasedin higher concentrations of the peptide. In the quantitative method, growth of both bacteria werecompletely inhibited at the concentration of ۱۰۰ mg/ml and as the concentration decreased theinhibition percentage also gradually decreased and reached below ۵۰% in the lowest concentration.Also, MBC was not observed in any of the plates at any concentrations.Conclusion : Based on the observations, it can be concluded that the microbial based featherhydrolysates have the ability to actively inhibit the growth of E. coli and S. aureus bacteria andconsequently they can be used as a safe feed additive in industries such as livestock and poultry.

کلیدواژه ها:

Keratinase ، Feather ، Peptide ، Antibacterial