The Influence of Ph and Temperature on the Antimicrobial Activity Of Cell-free Supernatant of Lactobacillus plantarum Sn13t Isolated from Stingless Bee Honey (Galo-Galo)

Abstract

This study aimed to measure the antimicrobial activity of Lactobacillus plantarum SN13T cell-free supernatant against bacterial pathogens at different pH and temperatures. L. plantarum SN13T was isolated from stingless bee honey (galo-galo). Some pathogenic bacteria were tested, namely Listeria monocytogenes VTO, Listeria monocytogenes, L. innocua, Staphylococcus aureus, Salmonella, Propionibacterium acnes, Pseudomonas, Klebsiella, Acinetobacter baumani, and Escherichia coli. Cell-free supernatant (CFS) L. plantarum SN13T had antimicrobial activity against pathogenic bacteria. The highest antimicrobial activity of CFS L. plantarum SN13T at pH 2 was against Salmonella bacteria (23.9 mm), and the smallest inhibition (10.2 mm) was against Acinetobacter baumani. While at pH 4, the highest antimicrobial activity of CFS was found in E. coli with an inhibition zone of 26.9 mm. CFS L. plantarum SN13T at different temperatures still had antimicrobial activity, even at more than 121oC. CFS L. plantarum SN13T produced the highest antimicrobial properties against Pseudomonas, both at 70, 100, and 121oC, while the lowest antimicrobial activity was shown against L. monocytogenes VTO.