Screening And Probiotic Properties Of Adhenece-forming Lactobacilli Strains

Adhension is one of the important criteria associated with the screening of probiotic microorganisms. The study selected 2 adhenece-forming lactobacillus strains, i.e., Lactobacillus salivarius CH10 and Lactobacillus murinus M8, from 15 lactic acid bacteria. The objectives of this study were: (1)to study their physical characteristics and the gastrointestinal tolerance firstly; (2) to evaluate their effects in the modulation of the intestinal flora of mice; and (3) to examine the safety of the two strains. This study attemptes to providing valuable data for the development of starter cultures and probiotics.1. MATH (microbial adhesion to hydrocarbons) method was used to assay the surface hydrophobicity and auto-aggregation of 15 lactobacilli strains. There are a relation between surface hydrophobicity and auto-aggregation. 3 lactobacillus strains, strains Ind3,CH10 and M8 showed higher hydrophobicity among these tested strains.2. Strain Ind3 did not grow at pH 2.5. However, strains CH10 and M8 showed good growth and gastrointestinal tolerance. They grew in a concentration of 18% sodium chloride and pH 2.5. They were resistant to bile salt and trypsin and pepsin. Moreover, strains CH10 and M8 were identified Lactobacillus salivarius and Lactobacillus murinus, respectively based on data from morphological characters, physiological and biochemical properties and 16S rRNA.3. Oral administration of strains CH10 and M8 (1×10~9cfu/mL) to rats showed that rats'weight the experimental animal's weight increased faster than those of the control group after 10-day. Compared to the control (without bacterial cells), the activity ofβ-D-galactosidase from intestinal flora was increased. The counts of beneficial microorganisms like bifidobacteria and lactobacilli in the intestinal flora in mice were significantly promoted. Oral adminisitration of the live cells of L.salivarius CH10 and L. murinus M8 for 10 days allowed rat's feces to have more bifidobacteria and lactobacilli as well as less Enterobacter, Clostridium perfringens and Enterococcus. It means that L. salivarius CH10 and L.murinus M8 modulates the intestinal microflora between helpful and harmful microorganisms.4. The analysis of kidney and liver from mices showed that there were no differences between the control group and the bacterial-feeding group. It means that strains CH10 and M8 might be safe as potential probiotic bacteria.