• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.289-296
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• 1990

The antimicrobial and antioxidant activities of grapefruit seed extract(GFSE), which was extracted with glycerine in the special schematic extraction apparatus, were investigated for handling and processing of fishery products. The effectivity of GFSE has been tried on sardine, mackerel and shrimp divided into six lots for each fishery product: control(no treatment) and five GFSE-treated samples. Samples were inoculated with Salmenella typhi, incubated for 24hrs at $30^{\circ}C$ in dextrose-tryptone broth medium and prepared for microbiological 8f chemical analysis and organoleptic assessment. The bacteriological analytical results with GFSE(250ppm) showed the reduction of $1.8\times10^6\to2.0\times10^4,\;1.9\times10^6\to1.8\times10^4$ and $1.6\times10^6\to2.7\times10^3$ in total bacterial count for sardine, mackerel and shrimp, respectively. The test results with GFSE(500ppm) showed a $100\%$ reduction of bacterial mackerel treated with GFSE(500ppm) was reduced to $1.1\times10^4$ and $9.0\times10^3$ respectively. Antioxidant effect of treatment with GFSE at 500ppm level for three products was significant. LSD test results on organoleptic parameter for the samples treated with various showed a significant influence on the appearance, odor and texture in which at concentration 500ppm level give the excellent scours compared to each control.

• Food Science and Preservation
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• v.16 no.1
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• pp.122-127
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• 2009

This study was to separate wild yeast from the Houttuynia Cordata Thunb(HC) extracts fermented in traditional way and investigate the characteristics of fermentation from the HC extracts. As a result, the longer the cultivation time, the more the contents of alcohol in $15^{\circ}Brix$ sugar solutions increased. When it reached to 90 hours since it cultivated, it ranked HCE 12%, HCD 11.2%, and HCA 10.5% in order. As for HCF, HCG, HCB, and HCC), this study has shown that the contents of alcohol were from 7.5% through 8.5%. As a result of selecting germ strains like HCE and HCD with the highest alcohol-genicity in the sugar solutions as separated yeast from HC and of comparing and reviewing the existing Saccharomyces germ strains and fermentation power in the medium of HC(Juice extraction of HC : Distilled water(1:1), this study has found out that 'pH' decreased from $4.09{\sim}4.12$ before fermentation through $3.57{\sim}3.78$ after fermentation. And, the sugar concentration decreased from $15.00{\sim}15.19^{\circ}Brix$ through $7.75{\sim}9.57^{\circ}Brix$ before fermentation. Also, the acid value increased from $0.138{\sim}0.210%$ before fermentation through $0.282{\sim}0.45%$ after fermentation. In addition, as the contents of alcohol became $3.6{\sim}4.6%$ after fermentation, isolates HCD and HCE from HC had higher value rather than ones of DJ97, YJK, R12, and RCY separated from persimmons, apples, and grapes. The result value of color was minimum $4.75{\pm}1.44$ and maximum $6.85{\pm}1.63$, and HCE marked the highest record among the items of sensory evaluation. The overall acceptability was in normal level like minimum $3.95{\pm}1.17$ and maximum $5.00{\pm}1.41$. It is considered as it could lower sensory evaluation because the acceptability of flavor was not satisfied. After all, the significance(p<0.05) among the germ strains was not recognized in aspects of color, flagrance, flavor, and overall acceptability.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.605-616
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• 2004

Subinhibitory concentrations (sub-MICs) refer to concentrations below minimum inhibitory concentrations (MICs). The antimicrobial agents may be present at relatively high concentration, at least higher than bacterial MIC and thereafter be deserted off a surface and function at sub-MICs, perhaps by interfering with bacterial metabolism. Consequently, the aim of this study was to determine the effects of growth, in the presence of sub-MICs of antimicrobial agents, on the cell surface properties and virulence factors of mutans streptococci and to investigate the efficacy of a chemical approach in vitro. Streptococcus mutans Ingbritt and Streptococcus sobrinus 6715-7 were used. Eight antimicrobial agents (Sanguinaria extract;SG, Chlorhexidine digluconate;CHX, Fluoride;F, Propolis;PP, Hydrogen peroxide;HP, Triclosan;TC, Sodium dodecyl sulfate;SDS Cetylpyridinium chloride; CC) were diluted serially in broth to determine MICs and to compare the growth rate, acid production, hydrophobicity, adhesion activity to saliva coated hydroxyapatite, glucan synthesis and cellular aggregation of experiment groups (in the presence of sub-MICs) with those of control (in the absence of antimicrobial agents). Sub-MICs of antimicrobial agents affected the growth of cells, hydrophobicity, and adhesion of bacteria to saliva coated hydroxyapatite and glucan synthesis. They also resulted in a significant reduction in pH after 12 hours (p<0.05). By cells pretreated with proteinase K, either the aggregation induced by antimicrobial agents was completely inhibited or the aggregation titers were markedly increased. According to the results of the present study, each antimicrobial agent at sub-MICs could affect similar as its known action mechanism and could continually inhibit cariogenic bacteria at such concentrations. Thus, the use of these antimicrobial agents would be one of the effective methods to prevent dental caries.

• Food Science and Preservation
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• v.22 no.5
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• pp.727-734
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• 2015

In this study, three GRAS (generally recognized as safety) strain was isolated from Doenjang and Cheonggukjang and identified as a protease-producing microorganism, following the appearance of a clear zone around its colony when cultured on a medium containing skim milk. Based on an analysis of the nucleotide sequence of 16S ribosomal RNA, the strains wereas identified as Bacillus amyloliquefaciens and wereas therefore named Bacillus amyloliquefaciens CDD5, Bacillus amyloliquefaciens CPD4, and Bacillus amyloliquefaciens CGD3. Here, we analyzed the protease and ${\alpha}$-glucosidase inhibitory activities of the three B. amyloliquefaciens strains. Among the isolated strains, B. amyloliquefaciens CGD3 exhibited the highest protease activity (9.21 U/mL, 24 hr). The protease activities of B. amyloliquefaciens CDD5 and B. amyloliquefaciens CPD4 reached 1.14 U/mL and 8.02 U/mL, respectively, at 48 hr. The proteases from the three B. amyloliquefaciens strains showed the highest activities within a pH range of 8.0-9.0 at $50^{\circ}C$, and casein was found to be the preferred substrate on evaluating enzyme activity in the substrate specificity assay. The B. amyloliquefaciens strains exhibited maximal growth when the nutrient broth medium had an initial pH within the range of 5.0-10.0, 6-9% sodium chloride (NaCl), and 5% glucose. B. amyloliquefaciens CDD5 exhibited a low ${\alpha}$-glucosidase inhibition rate (5.32%), whereas B. amyloliquefaciens CPD4 and B. amyloliquefaciens CGD3 exhibited relatively higher inhibition rates of 96.89% and 97.55%, respectively.

• Journal of Life Science
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• v.19 no.7
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• pp.956-962
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• 2009

The aim of this study was to assess the effects of dentifrice-contatning grapefruit seed extract (GSE) and processed sulfur solution (PSS) on antimicrobial effects against oral pathogens. We first evaluated the antimicrobial effects of GSE and PSS against oral microbes: Streptococcus mutans (Sm), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) and Candida albicans (Ca). When antimicrobial activity against Sm, Pi, Pg and Ca was tested, at 40 $\mu$l/disk, the inhibition zones of GSE were 11.0, 9.5, 8.0 and 9.0 mm, respectively. With the same method, the inhibition zones of PSS were 2.0, 3.5, 0.0 and 1.5 mm, respectively. In the micro broth dilution method, the MIC values of GSE against Sm, Pi, Pg and Ca were 0.24, 0.06, 0.10 and 15.63 $\mu$l/rnl, respectively. The MIC values of PSS were 0.12, 3.91,>125 and 7.81 $\mu$l/ml, respectively. When pH, refractive index, viscosity and color value of dentifrice-containing GSE and PSS were measured, there were no significant changes in these physical properties compared to the control samples. Antimicrobial activities of dentifrice products containing 0.5% GSE and 0.5% PSS against oral pathogens were 7.3, 4.3, 2.2 and 1.5 mm, respectively. According to these results, we conclude that there may be a role for GSE and PSS in the development of new oral supplies.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.219-228
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• 1990

A kanamycin resistance($Km^r$) gene was studied for its transfer in natural freshwater environments by using the natural bacterial isolate(M1) of DK1 and the DKC601 strain, $Km^r$ plasmid of which was genetically engineered from the NI strain. The transfer frequency ofthe $Km^r$ gene and rearrangement of the $Km^r$ plasmid were compared between the gnetically engineered microorganism(GEM) and the NI parental strain by conjugation with the same recipient strain. The transfer frequency of the $Km^r$ gene was about $9.1\times 10^{-12}-1.8\times 10^{-11}$ in both the GEM and NI strains at 5 to $10^{\circ}C$, but the frequency of the NI was about 10 times higher than that of the GEM at 20 to $30^{\circ}C$. The $Km^r$ plasmid in the transconjugants obtained by conjugation of the NI with the MY1 strain as a ricipient showed alot of rearrangement, but the $Km^r$ plasmid transferred from the GEM was stable without alteration of its size. When the MT2 strain was used as a recipient, however, such a rearrangement of the $Km^r$ plamid was observed in the transconjugants obtained from the GEM as well as the NI strain. In those transconjugants obtained from different mating pairs and water environments, the plasmid were appeared to decrease in their number as the period of conjugation time was prolonged, but only the $Km^r$ plasmid transferred from the GEM kept having its size of 52kb. Therefore, the $Km^r$ gene was transferred at the same rate from the GEM and NI strains in natural freshwater environment, but the gene of the GEM strain was more stable than the NIduring conjugation and the $Km^r$ plasmid was rearranged by changing the recipient strain for conjugation in any water environments.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.289-292
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• 2008

Trisodium phosphate 12 hydrate and citric acid monohydrate mixture showed the strong anti-sticking effect on Streptococcus mutans, Streptococcus mitis, and Streptococcus salivarius, which are adhered to glass beads. Each Streptococcus species was shaking-cultured in brain heart infusion broth containing three glass beads. After 18 hr, glass beads were slightly washed into normal saline by three-pin-pointed pincette. Each three glass-beads set was put into reagent -containing tubes, which have 40 mg of bits of weighing paper for gaining brushing effect as similar as brushing one's teeth. The tubes were shaken by vortex mixer for 10 min except non-oral microbe, Streptococcus agalactiae (5 min). The samples were colony-counted by serial agar dilution method. Experiment was repeated three times for each Streptococcus species. The relative ratios of bacterial de-adherence by reagents were calculated in comparison with normal saline control. The de-adherence degree of citric acid-trisodium phosphate-saline mixture (CTS, pH 6.0) against Streptococcus mutans came to an average of 12.5 times compared with normal saline control. Trisodium-saline (TS, pH 8.4) showed the average of 7.5 times, and citric acid-saline (CS, pH 4.6) showed 6.0 times compared to the control group. The bacterial de-adherence degree against Streptococcus salivarius was each 7.2,2.6 and 2.8 times in above reagent sequence in comparison with saline control. CTS and TS showed 2.4 and 3.4 times of anti-sticking effect on Streptococcus mitis respectively, but CS had no anti-sticking effect on this bacterium. CTS, TS and CS showed 0.7, 0.6, and 0.6 times on non-oral microbe, Streptococcus agalactiae, separately compared with saline control. These results show that oral Streptococcus mutans, Streptococcus salivarius, and Streptococcus mitis, which are causative of dental caries or subacute endocarditis, may be easily removed from oral cavity by CTS mixture. It is conceivable that our experimental results will enable the development of a new conceptive toothpaste to prevent dental caries or subacute endocarditis after drawing teeth.

• Tuberculosis and Respiratory Diseases
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• v.56 no.3
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• pp.261-268
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• 2004

Background : The resurgence of tuberculosis and outbreaks of multidrug resistant (MDR) tuberculosis have increased the emphasis for the development of new susceptibility testing of the Mycobacterium tuberculosis for the effective treatment and control of the disease. Conventional drug susceptibility testings, such as those using egg-based or agar-based media have some limits, such as the time required and difficulties in determining critical inhibitory concentrations, but these are still being used in many diagnostic laboratories because of no better lternatives, considering cost and accuracy. To overcome these limits, a rapid and simple method for new susceptibility testing, using live and dead assays, was applied for a bacterial cell viability assay to distinguish dead from live bacterial cells based on two-color fluorescence. Materials and Methods Strains : Forty strains were used in this study, 20 susceptible to all antituberculosis drugs and the other 20 resistant to the four first line antituberculosis drugs isoniazid, rifampicin, streptomycin and ethambutol. Antibiotics : The four antibiotics were dissolved in 7H9 broth to make the following solutions: $0.1{\mu}g\;isoniazid(INH)/m{\ell}$, $0.4{\mu}g\;rifampicin(RMP)/m{\ell}$, $4.0{\mu}g\;streptomycin(SM)/m{\ell}$ and $4.0{\mu}g\;ethambutol(EMB)/m{\ell}$. Results : Live and dead Mycobacterium tuberculosis cells fluoresced green and red with the acridin (Syto 9) and propidium treatments, respectively. These results are very well accorded with conventional drug susceptibility testing by proportional method on Lowensen-Jensen media (L-J) containing 4 drugs (INH, RMP, EMB and SM), showing a 93.7 % accordance rate in susceptible strains and 95% in resistant strains. Conclusion : The results of the drug susceptibility testing using the live and dead bacterial cell assay showed high accordance rates compared with the conventional proportion method on L-J. This finding suggests that the live and dead bacterial cell assay can be used as an alternative to conventional drug susceptibility testing for M. tuberculosis strains.

• KSBB Journal
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• v.23 no.6
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• pp.513-518
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• 2008

This paper described the extraction/purification of $\beta$-carotene from recombinant E.coli and evaluation of anti-wrinkle activity of purified $\beta$-carotene. No significant differences in extraction yields were observed when hexane or isobutyl acetate was used. However, extraction from wet-cell cake resulted in 2-fold higher amount of $\beta$-carotene than that from dry cells. Disruption of 5 g-wet cells by ultrasonic homogenizer, acetone dehydration, extraction with isobutyl acetate resulted in 36 mg of $\beta$-carotene corresponding to 61.2% of recovery. The formation and separation of $\beta$-carotene crystal improved the purity. 633 mg of $\beta$-carotene crystal with 93% purity was obtained from 223 g/L of wet-cell cake harvested from 2.5-L fed-batch culture broth. The cultures of normal human primary fibroblast were performed to investigate the effect of $\beta$-carotene on cytotoxicity as MTT assay and anti-wrinkle activity as collagen synthesis assays. $1.7{\mu}M$ of $\beta$-carotene was found to be optimal concentration at which 1.4-fold higher amount of collagen was synthesized than that in absence of $\beta$-carotene. This indicates that highly purified $\beta$-carotene can be obtained from recombinant E.coli by applying simple method with less toxic solvent and can be used in functional cosmetics as anti-wrinkle agent.

• Restorative Dentistry and Endodontics
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• v.34 no.6
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• pp.500-507
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• 2009

The purpose of this study is to compare the antibacterial effect of $Listerine^{(R)}$ on two microorganisms (P. gingivalis and E. faecalis) with various root canal irrigants (NaOCl, CHX, EDTA) and to identify possibility of using $Listerine^{(R)}$ as a root canal irrigant. Porphyromonas gingivalis ATCC 3327 and Enterococcus faecalis ATCC 29212 were used in this experiment. For the test irrigants, 0.5%, 1%, 2.5%, 5.25% NaOCl, 0.1%, 0.2%, 1%, 2% CHX, 0.5M EDTA (18.6% EDTA) and $Listerine^{(R)}$ were prepared. Distiled water was used as control. Two methods-1) Comparison of turbidity in broth and 2) Agar diffusion test-were used to determine the extent of antibacterial effect of $Listerine^{(R)}$ and to compare it with that of NaOCl, CHX, and EDTA. All solutions tested were effective against two bacterial strains compared with control (p < 0.001). Any concentration of NaOCl, CHX, and EDTA showed similarly high effectiveness against all bacterial strains. In all experiment, $Listerine^{(R)}$ showed significantly low antibacterial effect compared with the other root canal irrigants (p < 0.05). In conclusion, the results reflect remarkably low antibacterial effect of $Listerine^{(R)}$ as compared with root canal irrigants in general so it is not suitable for the root canal irrigant.