Food prospects of selenium enriched-Lactobacillus acidophilus CRL 636 and Lactobacillus reuteri CRL 1101.

M PESCUMA; B GOMEZ GOMEZ; T PEREZ-CORONA; G FONT; Y MADRID; F. MOZZI

Egmond aan Zee

Simposio; 12th International Symposium on Lactic Acid Bacteria; 2017

Selenium (Se) is an essential trace element present as SeCys in proteins (selenoproteins) involved in antioxidant functions, thyroid hormone production, viral expression genes, etc. Normally, animals incorporate Se via plant ingestion. Due to low vegetable consumption, Se deficiencies in humans have become a health problem. Additionally, Se has to be consumed as elemental Se (Se0) or as organic forms to be non-toxic. Some lactic acid bacteria can produce Se0 nanoparticles and selenoproteins. In this work, we aimed to study the cell behavior and the ability of Lactobacillus acidophilus CRL 636 and L. reuteri CRL 1101 to accumulate and biotransform Se in the presence of selenite. Moreover, the capability of the strains to survive in the presence of bile salts and at different pH values (4.0 and 8.0) after Se enrichment was evaluated. Both strains were able to grow, produce nanoparticles and accumulate Se, L. reuteri CRL 1101 being the strain that accumulated the highest (78 % at 24 h) amounts. Interestingly, SeCys was found in the cell pellets of both lactobacilli. Se-enriched strains showed lower cell growth rates when transferring them to the control medium (without Se); this effect was more detrimental in the presence of Se again, indicating that the strains could not adapt to the presence of this element. In contrast, the resistance of Se-enriched L. reuteri CRL 1101 to bile salts was improved. On the whole, results indicate that these strains could be administrated directly as probiotics or used them for formulating fermented products containing Se-enriched bacteria and nanoparticles.