Streptococcus macedonicus strains isolated from traditional fermented milks: resistance to gastrointestinal environment and adhesion ability.
Khaldi TEM, Kebouchi M, Soligot C, Gomri MA, Kharroub K, Le Roux Y, Roux E
Appl Microbiol Biotechnol. Jan 2019. doi: 10.1007/s00253-019-09651-z
COMMENT: Bacterial strains must meet certain selection criteria to be qualified as probiotic. Probiotic bacteria must have an ecological origin, survival capability to low pH and to bile salts stress and a good adhesion ability to epithelial cells.
In this article Streptococcus macedonicus, a lactic acid bacteria, is proposed like a good candidate as probiotic.
The first objective of this work was to isolate and identify different strains of S. macedonicus from raw milks fermented spontaneously.
In the second part of this study, we examined in vitro some properties that probiotic strains should possess.
The authors could isolate four new Streptococcus macedonicus strains. These strains resisted down to pH3. Three of them survived to a concentration of 10 nM of BSM (bile salts mixture) and the totality of the bacterial strains stuck on epithelial cells Caco2 TC7 and mucus-secreting cells HT29-MTX.
This first characterization indicates that S. macedonicus strains have the main prerequisites of probiotic, but further molecular and physiological studies are obviously required to highlight their potential influence on human health and their use as starter culture in the food industry.