Open AccessAntimicrobial Activity of Lactic Acid Bacteria Strains Isolated from Dadih against Escherichia coli
Author(s) -
Usman Pato,
Y Yusmarini,
Shanti Fitriani,
Nia Naidya Jonnaidi,
Mimi Sri Wahyuni,
Jeska Aryaningsih Feruni,
Irwandi Jaswir
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/709/1/012019
Subject(s) - antimicrobial , bacteriocin , lactic acid , preservative , bacteria , escherichia coli , microbiology and biotechnology , food science , listeria monocytogenes , biology , biopreservation , proteolytic enzymes , microorganism , streptococcus thermophilus , enzyme , chemistry , biochemistry , genetics , gene
Food is a material that is very susceptible to contamination by pathogenic microorganisms that affect the quality, shelf life and safety of food. One way to prevent contamination by pathogenic microorganisms is to add preservatives. Bacteriocin produced by lactic acid bacteria (LAB) is one of the natural food preservatives that are safe for human consumption. The aims of this study were to screen the ability of LAB isolated from dadih in inhibiting the growth of E. coli and to evaluate antimicrobial components that play a role in inhibiting the growth of E. coli. The antimicrobial sensibility of LAB to pH, heat and proteolytic enzymes was carried out using the referenced method. The results showed that supernatant from 12 LAB strains of dadih were able to inhibit the growth of E. coli with various inhibition zones. However, out of the 12 LAB, only 9 strains were found to have an inhibition zone of more than 4 mm. Then the 9 strains were tested for antimicrobial compounds, and it was found that 3 strains had antimicrobial activity derived from organic acids especially lactic acid, and 6 strains namely R-43, R-32, R-19, R-55, R-45 and R-41 had an antimicrobial effect in the form of bacteriocins based on the sensitivity test for pH, heat and enzyme treatments. Crude bacteriocin derived from 6 LAB strains inhibited the growth of E. coli, and the highest antimicrobial activity was found on Streptococcus lactis sub sp. diacelylactis R-43 with average inhibition zone of 8.9 mm. Based on this study, it can be concluded that the bacteriocin produced by S. lactis subsp. diacelylactis R-43 can be used as one of the natural preservatives for prevention from food-borne pathogen, E. coli.