• Journal of Dairy Science and Biotechnology
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• v.35 no.4
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• pp.249-254
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• 2017

The purpose of this study was to investigate the acid tolerance, bile acid tolerance, and fermentation activity of lactic acid bacteria isolated from Kimchi in the presence of hydrolysates of whey protein concentrate. Kimchi isolates DK109, DK119, DK121, DK128, DK211, DK212, and DK215, which were identified as Lactobacillus sp., and L. casei DK128 showed the highest acid and bile acid tolerance. To produce whey hydrolysates, enzymes were added to a 10% (w/v) whey protein concentrate (WPC) solution at 1:50 (w/v, protein). The viabilities of the DK strains were determined in the presence of low pH and bile salts. Then, yogurt was produced via fermentation with L. casei DK128, an isolate from Kimchi, in the presence of the following additives: CPP, WPC, and WPC hydrolysates (WPCH) generated by alcalase (A) or neutrase (N). The produced yogurts were subjected to various analyses, including viable cell counts (CFU/mL), pH, titratable activity, and sensory testing. After 8 h of fermentation, the pH and titratable activity values of all test samples were 4.2 and 0.9, respectively. The viable counts of LAB were $3.49{\times}10^8$, $5.72{\times}10^8$, $7.01{\times}10^8$, and $6.97{\times}10^8$, for the Control, CPP, A, and N samples, respectively. These results suggest that whey proteins have potential as dietary supplements in functional foods and that WPCH could be used in yogurt as a low-cost alternative to CPP.

• The Korea Journal of Herbology
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• v.39 no.1
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• pp.39-47
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• 2024

Objectives : This study evaluates how various traditional Korean herbal medicines assess MUC5AC expression for esophageal mucosal defense and analyzes the associated mechanisms involved in inflammation. Methods : Forty types of traditional Korean herbal medicines were assessed for in vitro antioxidant activities, and the real-time PCR method was employed to analyze MUC5AC expression under pH 4.5 conditions in human esophageal epithelial cells (HET-1A). Eight types of Korean herbal medicines were evaluated for in vitro antioxidant activities, and Reactive oxygen specise (ROS) expression was analyzed under bile salt (480 𝜇M) and pH 5.5 conditions in human esophageal epithelial cells (HET-1A). Simulation experiments involving bile salts and acidity were conducted for one hour to assess the efficacy of four drugs, and the activities of Mitogen-activated Protein Kinase (MEK), Nuclear Factor Kappa B (NF-𝜅B), and Cyclooxygenase-2 (COX-2) were detected through Western blot analysis. Results : Compared to the Normal group, the Control group exhibited higher ROS generation. Such increased ROS levels were significantly reduced by four extracts: Citrus Unshius Pericarpium (CUP), Cnidium officinale Rhizoma (CR), Ginseng Radix (GR), and Linderae Radix (LR). The protein expression of COX-2 decreased with the treatment of LR, CUP, and CR. Particularly, CUP and CR exhibited superior effects compared to other groups in inhibiting the phosphorylation of NF-𝜅B. Conclusion : Based on the results obtained, we have identified drugs that inhibit oxidative stress and inflammation caused by bile acid in esophageal epithelial cells. Our future plans involve comparing and analyzing the efficacy of these herbal medicines through animal experiments.

• Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.123-128
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• 2006

An epizootic causing mortality among cultured marine finfishes occurred in 1999 in the province of Kyoungsang, Korea. The disease was characterized by the presence of enterocele, abdominal swelling, and gastroenteritis. The causative bacteria were isolated from olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), turbot (Scophthalmus maximus) and the rearing water. These bacteria showed swarming activity on agar plates and yellowish or greenish colonies on thiosulfate-citrate-bile salts-sucrose (TCBS) agar plates, but no luminescence. The pathogen was identified as Vibrio harveyi based on morphological and biochemical characteristics and the sequence of l6S rDNA. The lethal doses (LD$_{50}$) of olive flounder and black rockfish were estimated to be $1.24\times10^6-1.36\times10^8$ and $3.24\times10^5-5.8\times10^7$ CFU/fish respectively following intraperitoneal injection.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.422-425
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• 2001

For isolating and identifying Bifidobacterium spp. originating from Korea, feces were sampled from healthy Korean infants nursery school and postpartum care center. Through the use of gram staining and microscopic examination for cell morphology, 87 bacterial strains presumed to be the Bifidobacterium strains were isolated from 59 Koreans. To identify the Bifidobacterium strains at the genus level, these bacteria were then analyzed using the TLC method. As a result, 29 of the isolated strains were confirmed as members of the genus Bifidobacterium. 29 Bifidobacterium strains were tested acid, bile salts and oxygen tolerance and investigated antioxidative effect specially. And determined the superiority of 5 strains out of 29 Bifidobacterium strains. Finally, the selected bifidobacterium was identified with using designed 16S-ITS rDNA primer.

• Korean Journal of Microbiology
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• v.23 no.3
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• pp.223-229
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• 1985

We have previously isolated seven strains of spiral form bacteria, which have shown several similar characteristics to Leptospira from patient with epidemic pulmonary hemorrhagic fever and matural paddy water. Further studies have performed to characterize them. All of the isolated bacteria were aerobic, gram negative and spiral form and their growth were completely inhibited at temperature below $13^{\circ}C\;and\;50^{\circ}C$. In sensitivity test to drugs, the bacteria were resistant to the bile salts, 5-Fu and Amphotericine B, but sensitive to the 8-Azaguanine. The isolated bacteria as well as 5 serotypes of Leptospira interrogans reacted the patient sera and it was also shown that antisera from rabbit immunized with the isolated bacteria reacted with 5 serotypes of Leptospira interrogans. These results suggest that the isolated bacteria may belong to the genus Leptospira.

• Parasites, Hosts and Diseases
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• v.35 no.2
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• pp.75-78
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• 1997

In uitro excystation studies were done on the metacercarial cysts of Echinostomn triuolvis obtained from the kidneys of naturally infected Rnna species tadpoles. Cysts were excysted in an alkaline trypsin-bile salts medium and the percentage of excystation was compared with that from previous studies done on cysts obtained from the kidneys of snails. The percentage of excystation of E. triuoluis metacercariae from tadpole kidneys was similar to that reported for previous studies on cysts obtained from experimentally infected gastropod hosts. The possible role of tadpoles as an agent for the transmission of Echinostomn and echinostomiasis to humans is discussed.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.429-432
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• 1991

In order to prepare probiotics, a strain which has resistant against acid, bile salts and antibiotics was isolated from infant and anirnat feces. Among these isolated strains, TK- 19 showed a strong acid tolerance and growth at 500 $\mu g$/ml of Na-deoxycholate. Also strain TK-19 was resistant to kanarnycin (30 $\mu g$/ml), streptomycin (10 $\mu g$/ml), nisin (50 $\mu g$/ml) and tetracycline (10 $\mu g$/ml). The isolated strain TK-19 was identified as Streptococcus faeciam, and was named Streptococcus faeciurn TK-19.

• Journal of Pharmaceutical Investigation
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• v.38 no.2
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• pp.127-134
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• 2008

Peroral administration is the most convenient one for the administration of pharmaceutically active compounds. Most of poorly water-soluble drugs administered via the oral route, however, remain poorly available due to their precipitation in the gastrointestinal (GI) tract and low permeability through intestinal mucosa. In this study, one of drug delivery carriers, lipid nanoparticles (LNPs) were designed in order to reduce side effects and improve solubility and stability in GI tract of the poorly water soluble drugs. However, plain LNPs are generally unstable in the GI tract and susceptible to the action of acids, bile salts and enzymes. Accordingly, the surface of LNPs was modified with polyethylene glycol (PEG) for the purpose of improving solubility and GI stability of paclitaxel (PTX) in vitro. PEG-modified LNPs containing PTX was prepared by spontaneous emulsification and solvent evaporation (SESE) method and characterized for mean particle diameter, entrapping efficiency, zeta potential value and in vitro GI stability. Mean particle diameter and zeta potential value of PEG-modified LNP containing PTX showed approximately 86.9 nm and -22.9 mV, respectively. PTX entrapping efficiency was about 70.5% determined by UV/VIS spectrophotometer. Futhermore, change of particle diameter of PTX-loaded PEG-LNPs in simulated GI fluids and bile fluid was evaluated as a criteria of GI stability. Particle diameter of PTX-loaded PEG-LNPs were preserved under 200 nm for 6 hrs in simulated GI fluids and bile fluid at $37^{\circ}C$ when DSPE-mPEG2000 was added to formulation of LNPs above 4 mole ratio. As a result, PEG-modified LNPs improved stability of plain LNPs that would aggregate in simulated GI fluids and bile solution. These results indicate that LNPs modified with biocompatible and nontoxic polymer such as PEG might be useful for enhancement of GI stability of poorly water-soluble drugs and they might affect PTX absorption affirmatively in gastrointestinal mucosa.

• 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.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.177-184
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• 2009

Three hundred lactic acid bacteria isolated from human feces were studied their probiotic characters to develop potential probiotics. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, thermal stability, antimicrobial, anticancer cell, and antiviral activity. Strain Miny-148 was selected as a potential probiotic bacterium which showed resistance to low pH, bile salts and thermal stability. On the basis of fatty acid profiles and 16S rDNA sequences analysis, the strain was identified as Lactobacillus pentosus (similarity 99.9%). The strain, L. pentosus Miny-148, showed broad antimicrobial spectrum against E. coli O157:H7, Shigella flexneri, Bacillus anthracis, Staphylococcus aureus, E. coli, Vibrio cholerae, V. vulnificus, Salmonella typhimurium, and Methicillin-resistant S. aureus (MRSA). Cell-free culture supernatant of the strain also inhibited against the growth of HT-29 colon cancer cell and transmissible gastroenterits virus.