• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.214-219
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• 1995

In fermentation of dairy products, bifidobacteria is used in conjunction with other lactic acid bacteria, such as L. acidophilus, L. bulgaricus and S. thermophilus, rendering the enumeration of bifidobacteria difficult. In order to develop optimum conditions for selective enumeration of bifidobacteria, we examined MIC of several antibiotics against various bifidobacteria and other lactic acid bacteria. The growth of L. acidophilus, L. bulgaricus and S. thermophilus were inhibited by lithium chloride at the concentration of less than 4 mg/ml, whereas growth inhibition of bifidobacteria occurred at concentrations over 6-10 mg/ml. Tetracycline and chloramphenicol were also found to selectively inhibit growth of other lactic acid bacteria at the concentration of 1-3 $\mu$g/ml. Addition of 6 mg/ml lithium chloride, 1 $\mu$g/ml, tetracycline or 3 $\mu$g/ml chloramphenicol to medium was found to be optimal for selective enumeration of bifidobacteria. By using these three inhibitory chemicals in the TPY medium, higher number of bifidobacteria were selectively isolated than with NPNL agar and LP agar.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.89-93
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• 1999

Stability and gastric acid resistance of Lactobacilli and Bifidobacteria in commercial yogurts were invcstigated. It was noted that there was significant differences of stability and gastric acid resistance among yo-wts. The sutvival of Lactobacilli and B#idohacleria in commercial yogurts decreased as a function of time during storage and showed in the range of $10^7$-$10^8$ cfulml. The lower the pH was, the lower survival of Lactobacillus and B~dobaclerium was observed. The survival of Lactobacillz and Bifidobacteria in three yogurts appeared to be $10^3$-10$^4$ cfuIml. In the case of yogurt containing Bifidobncterza- loaded capsules, the gastric acid resistance of the Rifidobncteria was greatly enhanced and the survival after treatment in a gastric juice for 120 min was over 10' cfulml.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.445-457
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• 2020

Prebiotics are defined as "Nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth and activity of bacteria in the intestine" and as defined improve host health. This study was carried out to investigate the effects of bifidobacteria (Bifidobacterium lactis BB12 and Bifidobacterium longum BB536) growth enhancer (BE0623) supplement as a prebiotic. The addition of BE0623, a growth promoting material for bifidobacteria, significantly increased bifidobacteria viable cells counts in fermented milk by about 45 to 75 times compared to the non-added control group. In addition, microscopic observation showed a significant effect on proliferation of bifidobacteria in fermented milk with added BE0623. The viable cell counts in bifidobacteria also increased roughly 102-fold compared to the control group (non-added BE0623) and was higher than that of commercial growth promoters. Each fraction obtained though the purification of BE0623 influenced the increase of bifidobacteria growth. Culturing bifidobacteria with a combination of fractions of BE0623 had a synergistic effect compared to culturing bifidobacteria with each fraction individually. When any of the fractions were not added, the effect of the growth enhancer on bifidobacteria was reduced. These results indicate that all fractions contain substances that promote the growth of bifidobacteria. Therefore, BE0623 is considered to be available as a growth promoting material for bifidobacterium.

• The Korean Journal of Community Living Science
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• v.12 no.1
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• pp.15-22
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• 2001

This study was conducted to find out the effect of fermented milk on lowering of serum and liver cholesterol in high diet. Sprague-Dawley male rats of 200g initial average weight were assigned to four experimental group : (1) high fat diet + milk (2) high fat diet + bifidobacteria (3) high fat diet + microcapsulated bifidobacteria (4) high fat diet + fermented milk by bifidobacteria. Milk, bifidobacteria, microcapsulated bifidobacteria and fermented milk by bifidobacteria were given 2ml per day. According to the result, there was lowering effect of serum and liver total cholesterol in fermented milk feeding group, Serum LDL-cholesterol was also low tendency in fermented milk by bifidobacteria feeding group. Accordingly, it was confirmed that the material that caused hypocholesteremic effect was not the bifidobacteria itself in fermented milk but the metabolic material produced in the fermentation, and it inhibited cholesterol synthesis in liver.

• Applied Biological Chemistry
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• v.36 no.3
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• pp.191-196
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• 1993

This method using the synthesis substrate of $5-bromo-4-chloro-3-indolyl-{\alpha}-galactoside\;(X-{\alpha}-Gal)$ was examined for the differential enumeration of Bifidobacteria and lactic acid-producing bacteria. Bifidobacteria possess a high level of ${\alpha}-galactosidase$ activity. Bifidobacterium longum KCTC 3215 exhibited the highest ${\alpha}-galactosidase$ specific activity (8.57 units/mg protein). Determination of ${\alpha}-galactosidase$ activity using the PNPG procedure showed that Lactobacillus, Streptococcus, Pediococcus, and Leuconostoc strain had lower ${\alpha}-galactosidase$ activity as compared to Bifidobacteria. The $X-{\alpha}-Gal$ based medium is useful to identify Bifidobacteria among lactic acid-producing bacteria since the enzyme action of ${\alpha}-galactosidase$ spills $X-{\alpha}-Gal$ substrate and releases indol which impacts a blue color to Bifidobacterial colonies on agar plates. All strains of Bifidobacteria appeared as blue colonies on MRS agar medium supplemented with $100\;{\mu}M\;X-{\alpha}-Gal$ while colonies of other lactic acid-producing bacteria appeared white or light blue.

• KSBB Journal
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• v.15 no.1
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• pp.1-8
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• 2000

The diffusion effect of simulated gastric juices into the various alginate vessel containing each biopolymer such as 0.3% soluble starch, whey, corn starch, agar, locust bean gum, guar gum, gum arabic, pectin, gelatin and 0.15% xanthan gum was tested by measuring the change of pH in the vessel. The degree of viability of bifidobacteria entrapped in each bead containing biopolymers was corresponded with the degree of diffusion inhibition of hydrogen into the each vessel. Therefore, The determination of diffusion inhibition of simulated gastric juices into the various vessel by measuring the change of pH in the vessel may be effectively used as the simple method to select the optimal entrapment lattice for the improvement of bifidobacteria viability. Bifidobacteria entrapped in alginate bead containing 0.15% xanthan gum whose lattice showed the lowest hydrogen diffusion were more significantly tolerant against bile salts and hydrogen peroxide than untrapped bifidobacteria. It was also observed that the viability of bifidobacteria entrapped in bead was nto nearly changed in milk adjusted pH 4.5 with organic adids at $4^{\circ}C$ for 10 days. Therefore, use of alginate containing 0.15% xanthan gum as a cell matrix for entrapping bifidobacteria was expected to improve the viability of bididobacteria in fermented milk products and develop the high value-added products.

• KSBB Journal
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• v.17 no.6
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• pp.531-536
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• 2002

In this study, we attempted to increase the survivability of bifidobacteria in simulated gastric juices and bile salts after cell entrapment with alginate and various food additives, such as erythritol, isomalt, palatinose, skim milk, xanthan gum, isomalto-oligosaccharide, fructo-oligosaccharide, galacto-oligosaccharide, pectin, and mono-sodium glutamate. Additionaly, the stability of bifidobacteria during storage was investigated by measuring survival rate at different temperatures, i.e. at 4$^{\circ}C$, 25$^{\circ}C$ and -20$^{\circ}C$. Bifidobacteria were immobilized in alginate beads and the survival rate was monitored. It was found that bifidobacieria entrapped with 2.5％, alginate showed the highest survival rate at 12%. After addition of the various protective agents, erythritol(1％) showed the best protective efficiency with a survival rate of 56.0% among the additives tested when exposed to simulated gastric juices for 3 h. Immobilized cells suspended in 5% skim milk and stored at 4$^{\circ}C$ survived significantly more than cells stored at 25$^{\circ}C$ and -20$^{\circ}C$. Consequently, the study shows that the survival rate of bifidobacteria immobilized in combination with 2.5% alginate beads and 1% erythritol may be signifcantly increased in simulated gastric juices and bile salts.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.154-162
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• 2010

This study was carried out to compare the efficacy and selectivity of TOS and BS media for enumeration of bifidobacteria in commercial fermented milk products. First, bifidobacteria was isolated from 20 fermented milk products, and all isolated bifidobacteria were identified by genomic technology as Bifidobacterium lactis. The two media significantly differed from each other with regard to the recovery of B. lactis, that is, the recovery of this organism was as much as 6 logs lower on BS medium than on TOS. When the concentration of BS solution (mixture of paromomycin sulfate, neomycin, sodium propionate, and lithium chloride) used in BS medium was reduced to 50% (BS50), a relatively high percentage recovery of bifidobacteria from pure cultures was achieved. Susceptibility tests to antibiotics and tests for selective agents for the isolated bifidobacteria and lactic acid bacteria were conducted. The BS solution inhibited some lactic acid bacteria and Bifidobacterium species, while mupirocin (MU) suppressed the growth of all tested lactic acid bacteria but not Bifidobacterium. As compared with BS50 medium, TOS with or without MU showed good bifidobacteria recovery and readily distinguishable colonies; in particular, TOS supplemented with MU had a high selectivity for bifidobacteria. In conclusion, all results suggested that TOS medium with or without MU was found to be suitable for selective enumeration of bifidobacteria from mixed cultures in fermented milk, and better in that capacity than BS medium.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.210-216
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• 1994

Phage utilizing medium and BL agar supplemented with antibiotic Tc(tetracycline) were developed as selective media for the isolation and counting of bifidobacteria in dairy products. The former was based on the host specificity of phage. When bifidobacteria and Lactobacillus casei HY 2782 were mixed together in dairy product, L. casei HY 2782 was laysed by J1 phage which has host specificity to L. casei HY 2782 whereas bifidobacteria grew well on the selective medium added wIth J1 phage. The latter was found to inhibit the growth of S. salivarius subsp. thermophilus, L. acidophilus, and L. casei, but commercial bifidobacteria grew well in Tc-containing BL agar.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.751-756
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• 1999

The inhibitory effect of antibiotics on growth of lactobacillus, streptococcus and bifidobacteria was examined to develop the selective media to isolate and enumerate bifidobacteria from the fermented foods containing various lactic bacteria. The growth of lactic bacteria was inhibited seriously but that of bifidobacteria was not inhibited by gentamycin or ripampicin at the concentration of more than $100\;{\mu}g/mL$. However lactic bacteria did not grow in MRS broth containing $50\;{\mu}g/mL$ of ampicillin and the growth inhibition of bifidobacteria occurred. The growth inhibition of bifidobacteria was more severe than lactic bacteria in $100\;{\mu}g/mL$ of fosfomycin. Therefore, the MRS medium containing $80\;{\mu}g/mL$ of neomycin sulfate, $50\;{\mu}g/mL$ of gentamycin, $50\;{\mu}g/mL$ of rifampicin, $15\;{\mu}g/mL$ of nalidixic acid and $3\;{\mu}g/mL$ of lithium chloride was concluded selective for bifidobacteria, but restrictive for the other lactic bacteria present in Kimchi and cheese.