Screening of Bile Resistance and Bile Precipitation in Lactic Acid Bacteria and Bifidobacteria

Abstract

A modification of the ecometric method was developed for a rapid screening of bile resistance in lactic acid bacteria and bifidobacteria. Validation of the MEM bile assay (modified ecometric method) was performed comparing the bile resistance index (RIbile) and the bile resistance ratio (R%). Most Bifidobacterium strains assayed were bile sensitive (83.3%), while only 62.1% of lactobacilli showed that behavior. Some bifidobacterial strains (55.6%) showed a crystalline precipitate when grown on solid medium supplemented with 0.5% ox bile. The crystalline structures produced by B. pseudolongum CIDCA 531 were isolated and analyzed by optical and scanning electron microscopy, thin-layer chromatography, melting point, and specific cholesterol reactions. Those studies confirmed the presence of cholesterol in these crystalline structures. On the other hand, none of the lactobacilli and streptococci studied had the ability to produce crystalline precipitates.

Bile-resistant derivatives obtained from non-intestinal dairy lactobacilli

“…lactis and L. helveticus strains. These findings agreed with those of Kociubinsky, Pe´rez, and de Antoni (1999) who found that most strains of L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp.…”

“…These are the first non-intestinal lactobacilli with acquired resistance to bile salts reported in literature. The concentration of bile (0.5%) for the adaptation of lactobacilli is within the range of the physiological concentrations of bile (Kociubinsky et al, 1999) and has been used previously by other researchers to mimic the small intestine environment (Mainville, Arcand, & Farnworth, 2005;Marteau, Minekus, Havennar, & Huis in't Veld, 1997).…”

Usefulness of a set of simple in vitro tests for the screening and identification of probiotic candidate strains for dairy use

“…All strains used in the present study were resistant or weakly inhibited by 0.3 g/100 mL bile, a concentration previously used by other researchers to mimic the small intestine environment (Mainville, Arcand, & Farnworth, 2005;Marteau, Minekus, Havennar, & Huis in't Veld, 1997). It is interesting to note the high resistance to bile salts of the strain L. gasseri LgF 37/1 , able to grow even in the presence of 1 g/ 100 mL bile salts, a concentration that is far beyond the physiological concentration of bile in the human gut (Kociubinsky, Pérez, & de Antoni, 1999). One mechanisms of bile salt resistance could be the capacity of deconjugating bile salts.…”

Mitogenic response and probiotic characteristics of lactic acid bacteria isolated from indigenously pickled vegetables and fermented beverages

“…The physiological concentration of bile acids in the small intestine is between 5,000 and 20,000 lM (Hofmann 1991). In this study, a concentration of 0.02% bile salts, equivalent to 50,000 lM was used, as was also done by Kociubinsky et al (1999), which is higher than the concentrations of 0.3 or 0.15% that have previously been used by other investigators of bacterial probiotic properties (Chou and Weimer 1999;Fernández et al 2003). Although it has been argued that LAB strains from vegetable origins are generally less bile-resistant (Mourad and Nour-Eddine 2006), the four LAB strains selected showed high resistance to bile and acid.…”