Technological potential of indigenous lactic isolates of an Algerian artisanal cheese: J’ben Elgafs

Abstract

This study was carried out to identify indigenous lactic acid bacteria from artisan cheese made from raw milk of indigenous cows in order to select potential starter cultures. Nine cheese samples prepared during the periods of milk production which is relative to the abundance of grass in the rangelands, i.e. three samples per season, in summer and autumn 2019 (medium season), in winter (low season) and in spring 2020 (high season), are produced according to traditional techniques and without exogenous seeding. 25 strains are presumptively identified using the reaction REP-PCR with primer (GTG) 5. The results are then confirmed by sequencing the 16S rDNA. Molecular identification reveals the presence of the species Lactococcus lactis, Enterococcus faecalis, Leuconostoc mesenteroides, and finally the isolates of Lactobacillus (Lb) represented by Lb. casei, Lb. fermentum and Lb. acidophilus. Coded isolates of Lactococcus lactis (STRD4) and Enterococcus faecalis (SMRB1) show good acidification capacity and the ability to produce antimicrobial compounds, while coded isolates of Lb. acidophilus (SA3) have good proteolytic capacity and produce exopolysaccharides, and the coded isolates (SHWI2, SHWI3) belonging to the species Leuconostoc mesenteroides, use citrate and produce diacetyl and acetoin. These strains appear to be interesting candidates for addition to the starter culture. This study provided a better understanding of the role of indigenous LAB in the quality of artisanal cheeses and the possibility of using the selected isolates as a potential starter culture for cheese production under controlled conditions.