Résumé:
The interest and exploration of biodiversity in subsurface ecosystems
have increased significantly during the last 2 decades. The aim of this study was to
investigate the in vitro probiotic properties of spore-forming bacteria isolated from
deep caves. Two hundred fifty spore-forming microbes were enriched from sediment
samples from 10 different pristine caves in Algeria at different depths. Isolates showing
nonpathogenic profiles were screened for their potential to produce digestive enzymes
(gliadinase and beta-galactosidase) in solid and liquid media, respectively. Different pro-
biotic potentialities were studied, including (i) growth at 37°C, (ii) survival in simulated
gastric juice, (iii) survival in simulated intestinal fluid, and (iv) antibiotic sensitivity and
cell surface properties. The results showed that out of 250 isolates, 13 isolates demon-
strated nonpathogenic character, probiotic potentialities, and ability to hydrolyze gliadin
and lactose in solution. These findings suggest that a selection of cave microbes might
serve as a source of interesting candidates for probiotics.
