Atividade antimicrobiana de peptídeos oriundos de proteínas clara do ovo caipira

Abstract

Food proteins are natural sources of bioactive substances, such as peptides with antimicrobial action, these biomolecules have a broad spectrum of microbicidal action, becoming a natural alternative to combat multidrug-resistant strains to drugs traditionally marketed in antimicrobial therapies. Therefore, the objective of this work was to prospect antibacterial peptides with molecular mass less than 3 kDa from free range egg white proteins, pre-treated by ultrasonic sonication (40 kHz), then submitted to enzymatic proteolysis. The maximum percentage of 32.40 ± 0.10% of protein hydrolysis was found from statistical inferences resulting from the combination of different sonication times and enzymatic hydrolysis, where the optimal times were 15 minutes and 5 seconds for sonication and 128 minutes and 13 seconds for enzymatic hydrolysis. The test with the highest degree of hydrolysis was subjected to fractionation by means of ultrafiltration in a cutting membrane with a porosity of 3 kDa. the fraction containing peptides with molecular mass less than 3kDa was submitted to the evaluation of the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (CMM) against the 9 reference bacterial strains. For the microorganism Enterococcus faecalis ATCC 29212 the MIC and CMM values were set at 90 μg.mL-1 and for the Listeria monocytogenes ATCC 19114, and Listeria monocytogenes ATCC 19117 the MIC and CMM values were 1ug.mL-1. For the strains Bacillus cereus ATCC 11778, Escherichia coli ATCC 8739, Escherichia coli ATCC 25922, Salmonella enteritidis ATCC 31194, Salmonella typhimurium ATCC 14028, and Serratia marcescens ATCC 13880 the values of MIC and CMM were defined as 90 ng.mL-1. Demonstrating the great bactericidal potential of the peptide fraction prospecting from enzymatic hydrolysis of free range chicken egg white proteins previously submitted to sonication. Thus, the proposed proteolysis is efficient for the prospecting of bioactive peptides with antibacterial activity.