Environmental Microbiology, Soil Microbiology & Microbial Biogeochemistry

Biography

Biography: Derriche ibtissem

Abstract

Statement of the Problem: Microorganisms from the genus Lactobacillus are responsible for spontaneous food fermentations. Some species, of lactobacilli have the “Qualified Presumption of Safety” status recognized by the European Food Safety Authority. Several of their strains are used as probiotics in foods, sometimes included in synbiotic combinations together with prebiotics.  New microbial strains from different sources represent an opportunity to use them for autochthonous food production.

Here we assessed the capacity of selected strains isolated from, human colustrum and aggregate of olive oil and identified by partical 16S rRNA gene sequencing as  L.brevis , and two L.paracasei casei respectivelly, to survive in vitro to gastrointestinal conditions: low pH, high bile salts concentrations and adhesion to HT29 intestinal cell line and  as well as antibiotic resistance against eleven antibiotics , we tested their growth and production of organic acids and volatile compounds by HPLC and gas chromatography, respectively,when they were incubated anaerobicallyin the presence of inulin, fructooligosaccharides or galactooligosaccharides as the main carbon sources. The strains were able to survive to simulated gastrointestinal conditions, to adhere to the HT29 cell line, and to grow in inulin, FOS, and GOS. However, they displayed different profiles of organic acids and volatile compounds, mainly depending on the prebiotic used and the microbial species.

Conclusion & SignificanceThe influence that the combined use of strains with prebiotics could exert on the organic acids and volatile formed in food and in the gut should be specifically assessed for each synbiotic combination and food product.