• Food Science of Animal Resources
• /
• v.38 no.6
• /
• pp.1315-1321
• /
• 2018

Bacteriocin is ribosomally synthesized by bacteria and inhibits closely related species. In this study we aimed at isolating lactic acid bacteria producing bacteriocin presenting anti-staphylococcal activity. A Lactococcus lactis strain was isolated from kimchi for the purpose and identified by 16S rRNA gene sequencing. As preliminary tests, optimal culture conditions, stabilities against heat, solvents, and enzymes treatments, and type of action (bacteriostatic or bactericidal) of the bacteriocin were investigated. The optimal culture conditions for production of the bacteriocin were MRS broth medium and $25^{\circ}C$ and $30^{\circ}C$ culture temperatures. The bacteriocin was acidic and the activity was abolished by a protease treatment. Its stability was maintained at $100^{\circ}C$ for 15 min and under treatments of various organic solvents such as methanol, ethanol, acetone, acetonitrile, and chloroform. Finally, the bacteriocin showed bactericidal action against Staphylococcus aureus where 200 AU/mL of the bacteriocin decreased the viable cell count (CFU/mL) of S. aureus by 2.5 log scale, compared with a control (no bacteriocin added) after 4-h incubation.

• Journal of Aquaculture
• /
• v.14 no.3
• /
• pp.157-163
• /
• 2001

The antibacterial effect of fish diet soaked in the extract of Salvia miltiorriza was tested to determine its levels of antibacterial activity, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The extract showed strong activity against gram positive bacteria, but was weak against gram negative bacteria. Concentration levels of 13.4~40.3 and 67.2~403.0 $\mu\textrm{g}$/ml were determined as the MIC and MBC, respectively. However, levels above 403.0 $\mu\textrm{g}$/ml was neither bacteriostatic nor bactericidal against Edwardsiella tarta, a gram negative strain. The fish diet, soaked in the extract of Salvia miltiorriza, inhibited the growth of all strains of Streptococcus genus and Vibrio anguillarum. The relationship formula between weight of fish diet and Salvia miltiorriza extract absorbed into the fish diet was Y＝2.4953X＋3.3276 ($R^2$= 0.9999). The antibacterial activity of the fish diet, soaked in the extract, was stable from 10 to 35$^{\circ}C$ during the storage period of 28 days.

• The Journal of the Korean Society for Microbiology
• /
• v.22 no.3
• /
• pp.233-240
• /
• 1987

The amniotic fluid provides a medium in which the fetus can readily move, cushions him against possible injury and helps him maintain an even temperature. Besides above mentioned functions, investigators reported that human amniotic fluid contains host-resistance factors which prevent bacteria from producing infectious disease and this activity shows difference among human racial groups or bacterial genera, species and strains. 40 amniotic fluid specimens from Korean women in their second and third trimesters of pregnancy were examined for inhibiting the growth of Escherichia coli. And various factors which might affect bacterial growth inhibiting activity such as pH, initial inoculum size, concentration of amniotic fluid, and heat resistance, were also tested using a strongly inhibitory amniotic fluid specimen. Finally plate diffusion tests were carried out using other strongly inhibitory amniotic fluid. The following results were obtained: 1. Of the 40 fluid samples examined, 18 specimens(45%) had inhibitory activity and samples from women in their second trimester of pregnanancy showed non-inhibitory activity(2 specimens). 2. The pH of the fluids varied between 7.43 and 8.33. There was no correlation between pH and inhibitory activity. 3. No. 19 amniotic fluid showed bacteriostatic activity after 24 hours incubation when an inoculum of $10^2$ organisms per milliliter was used, but non-inhibitory with an inoculum of $10^3$ and $10^4$ bacteria per milliliter. 4. The content of amniotic fluid in culture media influenced E. coli growth. At 90 percent, E. coli was inhibited growth but at 10 percent and 50 percent. 5. Inhibitory activity of No. 19 amniotic fluid was retained after heating to $50^{\circ}C$ for 30 minutes or 100^{\circ}C$ for 30 minutes. 6. Plate diffusion tests with No. 27 amniotic fluid showed that 0.7ml amniotic fluid gave clear zone of growth inhibition around the central well but 0.2ml and 0.1ml amniotic fluids were not.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.1
• /
• pp.20-26
• /
• 1986

Very little information is available in the literature on storage of fish sauce. Therefore, microbiological and chemical chracteristics during storage and quality of fish sauce were investigated and discussed to present data about the optimum storage condition. The chopped sardine meat was mixed with equal amount of water and $9\%$(w/w) of $75\%$ vital wheat gluten and then hydrolyzed by addition of commercial proteolytic enzymes such as bromelain, papaya protease, ficin and a enzyme mixture (Pacific Chem. Co.) for 4 hours at $52.5^{\circ}C$. The reaction mixture was heated for 30 min at $100^{\circ}C$ for enzyme inactivation, pasteurization and color development and then centrifuged for 20 min at 4,000 rpm. Table salt and benzoic acid were added for bacteriostatic effect and stored for 80 days at $15{\pm}1^{\circ}C$ and $30{\pm}1^{\circ}C$. The results were summarized as follows: 1. The amount of amino-nitrogen and pH of fish sauce were almost unchanged during storage. 2. Mininum concentration of salt for bacteriostatic activity was $9\%$(w/w) regardless of addition of benzoic acid. 3. the yields of amino-nitrogen were $63.1\%$ for the hydrolysate prepared without enzyme, $79.7\%$ for that with bromelain, $69.9\%$ with ficin, $74.3\%$ with papaya pretense, and $78.1\%$ with enzyme mixture, respectively. 4. The contents of amino-nitrogen were $4510.0mg\%$ on the dry basis for the product prepared by autolysis, $5483.2mg\%$ for that prepared with bromelain, $5305.7mg\%$ with ficin, $4994.1mg\%$ with papaya protease and $5582.3mg\%$ with the enzyme mixture, respectively. 5. The contents of crude protein were $51.35\%$ on the dry basis for the product prepared by autolysis and 55 to $59\%$ for prepared with commercial enzymes. 6. The hydrolysate prepared with the enzyme mixture revealed a little stronger meaty taste than any other products. 7. The level of crude protein in residues was still high ($69.5{\sim}77.2\%$ on the dry basis) and might be originated from the added vital wheat gluten.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.3
• /
• pp.34-40
• /
• 2012

In this study, new antibacterial materials were developed to manufacture a functional corrugated board. Sulfur solution, a new antibacterial solution made from inorganic sulfur in the laboratory, and other antibacterial mat erials were adopted to treat the surface of a linerboard. We measured the antibacteriocidal and bacteriostatic activities, as well as the fungal resistance of the surface-treated linerboards, to identify the antibacterial properties. The mechanical properties of the surface-treated linerboard were also determined in order to identify the effects of the antibacterial materials on linerboard properties. Linerboard treated with sulfur solution, PVOH, and sodium metasulfite showed the highest antibacterial activity, while linerboard treated with sulfur solution and nano sulfur showed the highest fungal resistance. It was identified that sulfur solution has effective antibacterial properties. The antibacterial materials did not affect the mechanical properties of the surface-treated linerboard, but the binder showed significant effects in terms of the burst strength, the compressive strength, and the stiffness of the linerboard.

• Journal of Life Science
• /
• v.32 no.10
• /
• pp.792-802
• /
• 2022

In this study, the antioxidant and antibacterial activities of Sophora japonica extracts were investigated to determine the potential of S. japonica as a functional food and medicinal materials. S. japonica was divided into flowers, fruits, and branches, and ethanol extraction was used. The total polyphenol and flavonoid contents were significantly higher in the flower and fruit extracts than in the branch extracts, but the ABTS and DPPH radical scavenging activity and ORAC value were higher in the branch extracts. Among the ethanol extracts of S. japonica, branch extracts showed strong antibacterial activity against Porphyromonas gingivalis, and the MIC was 0.2 mg/ml. Branch extracts showed bacteriostatic activity against P. gingivalis at a concentration of 0.4 mg/ml or less and bactericidal activity at a concentration of 0.6 mg/ml or more. Biofilm biomass production and cell growth of P. gingivalis in the culture medium treated with the branch extract at a concentration of 0.2-2.0 mg/ml were significantly decreased in a concentration-dependent manner. In addition, the mRNA expression of fimA and mfa1 associated with fimbriae formation in these cultures was suppressed in a concentration-dependent manner. Based on these results, S. japonica branch extracts can be used as functional food and medicinal materials, as demonstrated by their antioxidant and antibacterial activities against P. gingivalis and the inhibition of biofilm formation resulting from P. gingivalis.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.4
• /
• pp.550-555
• /
• 1997

Vibrio cholerae non-O1 (V. cholerae non-O1) was previously called nonagglutinable or noncholera vibrios, since it fails to react with polyvalent O1 antisera. This organism is biochemically and genetically indistinguishable from V. cholerae O1 except serological difference. V. cholerae non-O1 strains are often detected in the environment including bays, estuaries, and fresh water, and also found in food. Therefore it is designated food borne bacterium in Japan. However, research papers on V. cholerae non-O1 are very rare in Korea. In order to investigate bacteriological characteristics of V. cholerae non-O1, we isolated V. cholerae non-O1 from the environmental sea water. Among the isolated V. cholerae non-O1 strains, we selected the strain which had the most strong hemolytic activity, named as V. cholerae non-O1 FM-3. The optimum growth conditions of V. cholerae non-O1 FM-3 were $37^{\circ}C$ and pH 8.5 in BHI broth (containing $0.5\%$ sodium chloride), and it grew better than V. cholerae non-O1 ATCC 25872. But both were not able to grow in BHI broth added $5.0\%$ of sodium chloride or adjusted to pH 5.0. According to the experimental results on the susceptibility test against various antibiotics, there were no significant differences between the isolated strain and reference strain (V. cholerae non-O1 ATCC 25872). Most of the antibiotics examined had bacteriostatic action against V. cholerae non-O1 FM-3 while vancomycin, oxacillin, colistin, polymyxin B, and sulfadiazine had no bacteriostatic activity.

• Food Science of Animal Resources
• /
• v.31 no.3
• /
• pp.413-419
• /
• 2011

The antimicrobial effects of the natural flavonoids kaempferol, quercetin, apigenin, and naringenin as well as a novel flavonoid 7-O-butyl naringenin against the growth of four meat-born Staphylococcus aureus strains were evaluated. First, the flavonoids were screened for inhibitory effects against the growth of each strain using the paper disc diffusion method. Second, the growth inhibitory effects of flavonoids that showed antimicrobial activity were measured using the microplate method. Third, the bactericidal effects of flavonoids were evaluated in a 0.8% (w/v) NaCl solution. All flavonoids showed bacteriostatic effects at >20 mM. Among the flavonoids studied, quercetin was more effective than the others tested. However, the inhibitory effect of 7-O-butyl naringenin on growth of S. aureus KCCM 32395 was greater than that of quercetin at the same concentration. Additionally, 7-O-butyl naringenin exhibited significant bactericidal effects at >25 ${\mu}M$. When bacterial cells were examined using scanning electron microscopy, it appeared that the S. aureus membranes were damaged or morphologically changed when treated with quercetin and 7-O-butyl naringenin at 200 ${\mu}M$.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.9
• /
• pp.1374-1383
• /
• 2003

The effect of applying edible coating and addition of antioxidants (butylated hydroxyanisole (BHA) plus butylated hydroxytoluene (BHT) in a 1:1 ratio) on pork patties were investigated prior to achieve desired physico-chemical, microbiological and sensory qualities. For this, five treatments were conducted as (i) control (neither coated nor antioxidants treated); (ii) coated without antioxidants treated; (iii) coated and antioxidants added in the batter mix only (100 ppm); (iv) coated and antioxidants added in meat mix (100 ppm) only; and (v) coated and antioxidants added both in the batter mix (50 ppm) and the meat mix (50 ppm). Addition of antioxidants both in the batter mix and the meat mix significantly (p<0.05) reduced the microbial loads and thiobarbituric acid (TBA) values. The TBA values significantly (p<0.05) increased up to day 14 and then progressively increased with the advancement of each interval of storage days up to 28 days. Total plate count significantly (p<0.05) increased with the increase in storage days.Coliform and Staphylococcus aureus were absent throughout the storage days in all samples. Staphylococcus aureus however, were present in the control group at day 14 and in enrobed (coated) patties (without antioxidants treated) at 28th day. Addition of antioxidants to batter mix and meat mix did not substantially enhance bacteriostatic activity. Application of coatings and antioxidants retarded the loss of firmness, flavor, changes in appearance and color, and also other sensory attributes. Control patties were better with respect to microbial quality and TBA values but had poorer sensory quality than coated patties.

• Journal of the Korean Home Economics Association
• /
• v.43 no.3 s.205
• /
• pp.119-129
• /
• 2005

The antibacterial activities against Staphylococcus aureus of persimmon juice and persimmon juice dyed cotton fabrics were eveluated. We investigated the effects in pursuit of the proper treating conditions to use persimmon juice dye for comfortable and hygienic doffing. The antibacterial activities were estimated by test method KS K 0693 and the percentage reduction of bacteria at various contact conditions of test materials and bacteria. The results were as follows. no bacteriostatic activities (BS) of persimmon Juice were more than $99.98\%$ and the increase was dose-dependent according to concentration from $1\%$ to $10\%$. However, bactericidal activities (BC) were not found BS increased from $99.97\%$ to $100\%$ and BC from $79.74\%$ to $100\%$ with increasing persimmon juice concentration of cotton fabrics from $10\%$ to $100\%$. Antibacterial effects were significantly shown at $10\%$ of persimmon juices. BS increased from $75.69\%$ to $100\%$ and BC from $65.89\%$ to $100\%$ over 18 hours of contact time and continued for 50 hours. BS of $100\%$ persimmon juice dyed cotton fabrics increased from $96.56\%$ to $98.20\%$ and BC from $-136\%$ to $65\%$ at different incubation temperatures of $17\pm1^{\circ}C$, $27\pm1^{\circ}C$ and $37\pm1^{\circ}C$. BS ranged from $99.06\%$ to $99.99\%$ and BC from $84.31\%$ to $95.10\%$, according to the initial bacterial density from $4.08\times10^7$ to $4.08\times10^5$. Sixty-seven percent of subjects of answered not to smell any odor from persimmon juice dyed cotton fabrics by subjective test.