Antifungal Activity of Lactic Acid Bacteria Isolated from Nem Chua

Abstract

Lactic acid bacteria (LAB) play an important role in fermented food preservation thank to their antifungal ability as well as bacteriocin activity. Fermented meat products including Nem chua are usually placed under negative effects due to typical manual production process, uncontrolled ambient preservation condition, and consuming without cooking. In this study, the antifungal ability of lactic acid bacteria isolated from Nem chua was examined. Five Nem chua samples were collected at the local markets in Mekong Delta, Vietnam. They had good sensory evaluation (typical odor of lactic acid fermentation product like sour, meat and leaf odor) with the total score over 7/10. Average pH for 5 samples was found at 4.7 and average lactic acid content was 1.6 g/100 g of sample. The results of enumeration of total plate count and mould were found to be acceptable (3.0 x 10 7 CFU/g and 3.3 x 10 3 CFU/g, respectively) and average LAB count was 2.2 x 10 7 CFU/g. From 5 samples of Nem chua , 19 isolates of LAB and 9 isolates of mould were collected. Antifungal activity was found in most LAB isolates with various degrees. Only 9 LAB isolates, 47% (P32B, P41A, V13A, P21B, P31B, R11B, R14B, R22B and K34B) exhibited strong activity against 7/9 mould isolates (over 10+ degree of activity). Isolates P32B, P41A and V13A were chosen to be sequenced due to their strong inhibitory activity and were identified as Lactobacillus plantarum (P32B and V13A) and Pediococcus pentosaceus (P41A).