• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.87-91
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• 1996

The optimum temperature and pH for the enzyme activity were 45$^{\circ}C$ and 10.0, respectively. The enzyme was stable in a pH range of 5 to 10, and 62% of its activity was lost on heat treatment of 60$^{\circ}C$ for 20 min. The activity of the purified enzyme was inhibited by $Fe^{2+},\;Zn^{2+}\;and\;Pb^{2+}$, and slightly activated by $Mn^{2+}\;and\;Ca^{2+}$. ${\gamma}$-Chloromercuribenzoic acid, 2,4-dinitrophenol and $H_{2}O_{2}$ did not show inhibitroy effect on the lipolytic activity of the alkaline lipase but ethylenediaminetetraacetic acid inhibited the enzyem activity. This suggested that the enzyme have metal group in its active site. Sodium salts of bile acids stimulated the enzyme activity. Analysis of hydrolyzates of olive oil after the reaction revealed that Serratia liquefaciens AL-11 produced non-specific lipolytic enzyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.396-401
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• 2012

To select potent probiotics from lactic acid bacteria in Yulmoo Kimchi, an in vitro and stimulated human intestinal model system (SHIMS) test were performed. One Leuconostoc mesenteroides strain from five strains of Yulmoo Kimchi and one Lactobacillus plantarum from 12 strains of KCTC and KCCM were selected according to survival in acidic and bile salts conditions. Between the two species, Leu. mesentroides displayed higher survival activity in a SHIMS test. The strain was identified as Leu. mesentroides by 16S rRNA sequencing and was designated as Leu. mesentroides K01.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.516-525
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• 2012

LAB were isolated from makgeolli locally produced around Jinju, Gyeongnam, S. Korea during spring of 2011. Randomly selected 11 isolates from MRS agar plates were identified first by API CHL 50 kits and then 16S rRNA gene sequencing. All 11 isolates were identified as Lactobacillus plantarum. Among them, ST4 grew in MRS broth with ethanol up to 10%, showing the highest alcohol resistance. L. plantarum ST4 was moderately resistant against acid and bile salts. When cellular proteins of L. plantarum ST4 under ethanol stress were analyzed by two-dimensional gel electrophoresis (2DE), the intensities of 6 spots increased, whereas 22 spots decreased at least 2-fold. Those 28 spots were identified by peptide mass fingerprinting (PMF). FusA2 (elongation factor G) increased 18.8-fold (6% ethanol) compared with control. Other proteins were AtpD (ATP synthase subunit beta), DnaK, GroEL, Tuf (elongation factor Tu), and Npr2 (NADH peroxidase), respectively. Among the 22 proteins decreased in intensities, lactate dehydrogenases (LdhD and LdhL1) were included.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.571-575
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• 1993

Effect of surface hydrophobicity of soybean peptides on serum cholesterol in rats was investigated. Soybean protein(ISP), casein(CNP), and their peptic hydrolyzates fractionated by acid precipitations (SHT, SH8, SH6, SH4, CHT, CH6, CH5, CH4) were fed to rats and the concentration of serum cholesterol and the fecal steroid excretion were measured. And surface hydrophobicities of the peptide fractions were measured by determining by the ANS flourescence intensity and SDS binding capacity. It was found that the higher the surface hydrophobicity of peptides was, the more the fecal steroids excreted(r=0.801) and the lower the concentration of serum cholesterol became(r=-0.868). However, there was no relationship between SDS surface hydrophobicity and fecal steroids or serum cholesterol. ANS surface hydrophobicity of soybean protein was increased by enzymatic hydrolysis. These results suggest that high surface hydrophobicity of peptides formed during digestion is responsible for the hypocholestrolemic effect of soybean protein through the hydrophobic interaction between the peptides and bile salts in rats.

• Korean Journal of Veterinary Research
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• v.52 no.3
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• pp.169-176
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• 2012

Probiotics colonize the intestines and exert an antibacterial effect on pathogens. Therefore, probiotics could be used as a preventive agent against lethal infections. To isolate probiotic microorganisms, 116 bacterial strains were isolated from healthy cow's milk and were subjected to Gram-stain, morphology and biochemical analyses, Vitek analysis, and 16S rRNA analysis. One of the strains identified as Bacillus (B.) thuringiensis 87 was found to grow very well at pH 4.0~7.0 and to be resistant to high concentrations of bile salts (0.3~0.9% w/v). B. thuringiensis was susceptible to the antibiotics used in the treatment of bovine mastitis, yet it exhibited an antimicrobial effect against Staphylococcus (S.) aureus 305. Moreover, it protected mice from experimental lethal infections of E. coli O55, Salmonella typhimurium 01D, and S. aureus 305 through a significant induction of interferon-${\gamma}$, even at four-week post-administration of B. thuringiensis. Although oral administration of B. thuringiensis 87 did not provide significant protection against these lethal challenges, these results suggest that B. thuringiensis 87 could be a feasible candidate as a probiotic strain.

• Journal of Pharmaceutical Investigation
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• v.24 no.2
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• pp.57-65
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• 1994

To increase the dissolution rate of practically insoluble biphenyl dimethyl dicarboxylate (DDB), various solid dispersions were prepared with water soluble carriers, such as povidone (PVP K-30), poloxamer 407, sodium deoxycholate (SDC) and polyethylene glycol (PEG) 6000, at drug to carrier ratios of 1:3, 1:5 and 1:10 (w/w) by solvent or fusion method. Dissolution test was performed by the paddle method. The dissolution rate of DDB tablets (25 mg) on market was found to be very low (11.44, 9.02 and 6.42% at pH 1.2, 4.0 and 6.5 after 120 min, respectively). However, dissolution rates of DDB from various solid dispersions were very fast and reached supersaturation within 10 min. DDB-PEG 6000 solid dispersion appeared to be better in enhancing the in vitro dissolution rate than others. Furthermore, the incorporation of DDB and phosphatidylcholine (PC) into ${\beta}-cyclodextrin$ at ratios of 1:2:20, 1:5:20 and 1:10:20 resulted in a 4.9-, 11.2- and 19.6-fold increase in DDB dissolution after 120 min as compared with the pure drug, respectively. This might be attributed to the formation of lipid vesicles which entrapped a certain concentration of DDB during dissolution. On the other hand, the permeation of DDB through rabbit duodenal mucosa was examined using some enhancers such as SDC, sod. glycocholate (SGC) and glycyrrhizic acid ammonium salt (GAA). Only trace amounts of DDB were found to permeate through deuodenal mucosa in the absence of enhancer. SDC was found to markedly decrease the permeation flux of DDB, however, SGC and GAA (5 mM) enhanced the flux of DDB 1.6 and 2.4 times higher as compared with no additive, respectively.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.320-324
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• 2010

Five different enrichment methods were studied to find an optimal method to recover Yersinia enterocolitica from swine feed samples. When the recovery of Y. enterocolitica GER-C (serotype O:3) strain was studied at 1000 CFU/g feed, phosphate-buffered saline (PBS) enrichment at $4^{\circ}C$ and PBS plus sorbitol and bile salts (PSB) enrichment at $4^{\circ}C$ and $21^{\circ}C$ were not effective (< 22%). In contrast, both irgasan-ticarcillin-potassium chlorate (ITC) and tryptic soy broth plus polymyxin B sulfate and novobiocin (TSBPN) enrichment methods showed a full recovery (100%) at 100-1000 CFU/g feed. At 10 CFU/g feed, both ITC and TSBPN methods still recovered the strain (> 50%). In recovery of ATCC 9610 (serotype O:8) strain, TSBPN method was more sensitive than any other methods (P < 0.05) at 1000 CFU/g feed. Using TSBPN method, the strain was still recovered at 100 CFU/g feed, but not at 10 CFU/g feed. With its sensitivity and relatively simple recipe, TSBPN was most desirable method to recover Y. enterocolitica from swine feed samples.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.31-39
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• 2012

The purpose of this study was to isolate bacteriocin-producing bacteria with antagonistic activities against pathogens from the intestines of pigs for probiotic use. Lactobacillus sp. AP 116 possessing antimicrobial property was selected from a total of 500 isolates. The AP 116 strain showed a relatively broad spectrum of inhibitory activity against Listeria monocytogenes, Clostridium perfringens, Pediococcus dextrinicus, and Enterococcus strains using the spot-on-lawn method. Bacteriocin activity remained unchanged after 15 min of heat treatment at $121^{\circ}C$ and exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. Maximum production of bacteriocin occurred at $34^{\circ}C$ when a pH of 6.0 was maintained throughout the culture during fermentation. According to a tricine SDS-PAGE analysis, the molecular weight of the bacteriocin was approximately 5 kDa. The isolate tolerated bile salts and low pH, and also induced nitric oxide (NO) in mouse peritoneal macrophages. Bacteriocin and bacteriocin-producing bacteria, such as Lactobacillus sp. AP 116, could be potential candidates for use as probiotics as an alternative to antibiotics in the pig industry.

• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.58-63
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• 2007

Bifidobacteria are probiotic organisms that provide both flavor and health benefits when incorporated as live cultures into commercial dairy products. Because bifidobacteria are very sensitive to environmental conditions (acids, temperature, oxygen, bile salts, the presence of other cultures, etc.), their viability in human gastrointestinal tract is limited. The microencapsulation of bifidobacteria is a process to protect them against harsh environmental conditions, thereby increasing their viability while passing through human gastrointestinal tract. To confirm the survival rate of microencapsulated Bifidobacterium breve CBG-C2 in milk, their survival rate was compared with several kinds of free bifidobacteria and lactic acid bacteria in commercial yogurt products under simulated gastric and small intestinal conditions. Double-microencapsulation of the bacteria was employed to increase the survival rate during digestion. The outer layer was covered with starch and gelatin to endure gastric conditions, and the inner layer was composed of a hard oil for the upper small intestinal regions. Almost all microencapsulted bifidobacteria in the milk survived longer than the free bifidobacteria and lactic acid bacteria in the commericial yogurt products under the simulated gastric conditions. Numbers of surviving free bifidobacteria and lactic acid bacteria in the commercial products were significantly reduced, however, the viability of the microencapsulated bificobacteria in the milk remained quite stable under gastric and small intestine conditions over 3$\sim$6 hrs. Thus double-microencapsualtion of bifidobacteria in milk is a promising method for improving the survival of bifidobacteria during the digestive process.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.967-982
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• 2021

Probiotics are living microorganisms that, when administered in adequate amounts, provide a health benefit to the host and are considered safe. Most probiotic strains that are beneficial to human health are included in the "Lactic acid bacteria" (LAB) group. The positive effects of probiotic bacteria on the host's health are species-specific and even strain-specific. Therefore, evaluating the probiotic potential of both wild and novel strains is essential. In this study, the probiotic characteristics of Lactobacillus brevis KT38-3 were determined. The strain identification was achieved by 16S rRNA sequencing. API-ZYM test kits were used to determine the enzymatic capacity of the strain. L. brevis KT38-3 was able to survive in conditions with a broad pH range (pH 2-7), range of bile salts (0.3%-1%) and conditions that simulated gastric juice and intestinal juice. The percentage of autoaggregation (59.4%), coaggregation with E. coli O157:H7 (37.4%) and hydrophobicity were determined to be 51.1%, 47.4%, and 52.7%, respectively. L. brevis KT38-3 produced β-galactosidase enzymes and was able ferment lactose. In addition, this strain was capable of producing antimicrobial peptides against the bacteria tested, including methicillin and/or vancomycin-resistant bacteria. The cell-free supernatants of the strain had high antioxidant activities (DPPH: 54.9% and ABTS: 48.7%). Therefore, considering these many essential in vitro probiotic properties, L. brevis KT38-3 has the potential to be used as a probiotic supplement. Supporting these findings with in vivo experiments to evaluate the potential health benefits will be the subject of our future work.