Bifidobacterium longum ssp. Infantis
A basic information
Bifidobacterium longum belongs to the genus Lactobacillus, a gram-positive bacterium, does not produce spores, has no flagella, does not move, and is strictly anaerobe.
Active lactic acid bacteria content ≥ 10 billion cfu / g, powder, packed in aluminum foil bag, 1 kg / bag.
1. Bifidobacterium infantis can be isolated from the feces of healthy adults and infants. It is one of the most common flora in the human intestine and is most widely distributed at the end of the human large intestine. However, its number will decrease by a logarithmic value during weaning.
2. Bifidobacterium infantis fermentation broth against pathogenic Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Pseudomonas aeruginosa, F. dysenteriae, Escherichia coli, Candida albicans, Proteus There is a significant inhibitory effect on growth and reproduction;
3. Bifidobacterium infantis has good targeting and distribution ability to tumor tissues, and it is mainly distributed in tumor hypoxia area in tumor tissues. Bifidobacterium infantis is not pathogenic and can be selectively colonized in the hypoxic area of the tumor, giving it the natural advantages of a vector system for gene therapy and a good prospect as a carrier for tumor gene therapy;
Size and colony morphology
1. Size Under the electron microscope, the cells will have irregular shapes such as curved, Y-shaped or V-shaped, but they are less branched, and the cells are more slender and do not form chains, as shown in the figure. .
2. Colony morphology The colonies are round, convex, smooth, neat edges, opaque, and colonies are white or milky white.
Suitable for growing environment
1. Bifidobacterium infantis is suitable for growth under absolute anaerobic environment. Increasing the concentration of carbon dioxide may promote growth. The growth temperature range is 20 ～ 45 ℃, the most suitable growth temperature is 36 ～ 38 ℃, and the pH range is 6.5 ～ 7.0. In between, the pH value does not grow at 4.5 to 5.0 and 8.0 to 8.5.
2. This strain is a strictly anaerobic bacteria without enzyme activity. The tolerance to oxygen varies with the number of passages. When aerobic is present, a small amount of enzyme is activated to remove a small amount of hydrogen peroxide, while hydrogen peroxide The presence of glutamate will destroy the enzymes produced by carbohydrate metabolism, which will lead to difficult growth of bacteria.
1 culture characteristics: culture in the laboratory, can be cultured with MRS medium.
2 Biochemical characteristics: Bifidobacterium infantis does not produce carbon dioxide, propionic acid and butyric acid during carbohydrate metabolism, while acetic acid and lactic acid are the main metabolites, and it also produces a small amount of formic acid and succinic acid; it can break down the human intestine. Digested fiber or glycan does not break down a few sugars such as xylose and mannose.