Cell surface characteristics of Lactobacillus casei subsp. casei, Lactobacillus paracasei subsp. paracasei, and Lactobacillus rhamnosus strains

Abstract

Hydrophilic and electrostatic cell surface properties of eight Lactobacillus strains were characterized by using the microbial adhesion to solvents method and microelectrophoresis, respectively. All strains appeared relatively hydrophilic. The strong microbial adhesion to chloroform, an acidic solvent, in comparison with microbial adhesion to hexadecane, an apolar n-alkane, demonstrated the particularity of lactobacilli to have an important electron donor and basic character and consequently their potential ability to generate Lewis acid-base interactions with a support. Regardless of their electrophoretic mobility (EM), strains were in general slightly negatively charged at alkaline pH. A pH-dependent behavior concerning cell surface charges was observed. The EM decreased progressively with more acidic pHs for the L. casei subsp. casei and L. paracasei subsp. paracasei strains until the isoelectric point (IEP), i.e., the pH value for which the EM is zero. On the other hand, the EM for the L. rhamnosus strains was stable from pH 8 to pH 3 to 4, at which point there was a shift near the IEP. Both L. casei subsp. casei and L. paracasei subsp. paracasei strains were characterized by an IEP of around 4, whereas L. rhamnosus strains possessed a markedly lower IEP of 2. The present study showed that the cell surface physicochemical properties of lactobacilli seem to be, at least in part and under certain experimental conditions, particular to the bacterial species. Such differences detected between species are likely to be accompanied by some particular changes in cell wall chemical composition.

Biomineralization of carbonates by Halobacillus trueperi in solid and liquid media with different salinities

“…The bacterial metabolism tends to modify these parameters leading to modifications of the cell surface during the culture growth phases. On the other hand, the influence of the physicochemical parameters of the medium on the cell surface varies among different bacterial species [41].…”

Association patterns ofPseudomonas aeruginosaclinical isolates as revealed by virulence traits, antibiotic resistance, serotype and genotype

“…After incubation, bacteria were washed twice in 0.01 M PBS, pH 7.4 by centrifugation for 20 min at 1000 g and were then resuspended in 0.1 M PBS, pH 7.4 (Jucker et al, 1996;Otto et al, 1999;Yu & Li, 2005) to a standard inoculum corresponding to c. 10 8 CFU mL À1 . Because some solvent droplets, namely n-hexadecane, are negatively charged in aqueous solutions, there is a need to use high concentrations of electrolytes in order to avoid charge interferences (Pelletier et al, 1997). Afterwards, 250 mL of the solvent was added to each triplicate sample (1 mL each) and the two phases were mixed by vortexing for 1 min.…”

In vitroevaluation of the mucin-adhesion ability and probiotic potential ofLactobacillus mucosaeLM1

“…All tested strains showed weak acidic characteristics (less than 40% affinity to ethyl acetate) and highly basic characteristics (60-90% affinity to chloroform), similar to Lactobacillus acidophilus M92 (Kos et al 2003) and Lact. rhamnosus (Pelletier et al 1997). Most adhesive probiotic lactobacilli strains showed strong basic and electron-donating properties, demonstrating preferential monopolarity towards chloroform (Kos et al 2003;Pelletier et al 1997).…”