Effect of Low pH on the Ability of Lactobacillus acidophilus to Survive and Adhere to Human Intestinal Cells

Abstract

Lactobacillus acidophilus was suspended in broth and buffer at pH 2, 3 and 4 and incubated at 37°C for 2 hr. In both broth and buffer at pH 2, viable cell numbers decreased rapidly, and none were recovered. after 45 min. At pH 4 in broth and buffer, the number of cells was not significantly reduced in 2 hr. In potassium phthalate buffer at pH 3, no viable cells were recovered after 30 min, while in KC1 buffer and broth at pH 3, no significant reduction was seen. Cells subjected to low pH for up to 5 h were able to adhere to human intestinal cells in vitro. Exposure to low pH did not appear to disrupt the ruthenium red staining layer exterior to the cell wall.

Probiotic Characteristics of Lactobacillus spp. Isolated from Fermented Milk Product Dahi

“…However, some LAB such as L. acidophilus and L. casei, are capable of surviving in the presence of bile due to their ability to deconjugate bile acids. Bile resistance and the ability of LAB to inhabit the intestinal tract appear to be correlated (Gilliland and Speck, 1977;Hood and Zottola, 1988). Most of the L. acidophilus strains are sensitive in the presence of 0.3% bile, as reported by other researchers (Gupta, et al, 1996;Jacobsen, et al, 1999).…”

Producing Probiotic Peach Juice

“…The viability of probiotic organisms is also influenced by inhibitory components such as lactic acid during fermentation and cold storage. Some other Conditions such as increased acidity resulting from the fermentation process can reduce the survival and viability of probiotic bacteria (16,(20)(21)(22). As mentioned above, we found that L. delbrueckii and L. plantarum could survive the high acidity and low pH in fermented peach juice.…”

Probiotic properties of Enterococcus faecium CE5-1 producing a bacteriocin-like substance and its antagonistic effect against antibiotic-resistant enterococci in vitro

“…The acid tolerance of LAB depends on the pH profile of H + -ATPase and on the composition of the cytoplasmic membrane. This is largely influenced by the type of bacterium, the growth medium, and the incubation conditions (Hood and Zoitola, 1988).…”