• Korean Journal of Microbiology
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• v.34 no.3
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• pp.154-161
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• 1998

To investigate whether the introduced genetic marker is useful to detect the survivalship and activity of the natural bacteria under the stressed conditions, one Gram-negative isolate, KP964 was transformed to the luminous phenotype by transferring luxAB gene. Under the starvation-stress this luminous bacterial culturability (determined by colony-forming-units [CFU] on agar plate) decreased rapidly below the detection limit by 37 days, while its total cell number (determined by AODC) remained almost the same as its initial inocular size. At that time period, the viable cell number was estimated to be 1400 times higher than its CFU number. The bioiuminescence (determined by relative light units [RLU]) produced under the same condition was also monitored and found to decrease more rapidly than the culturability by 5-fold. Under the other stresses, e.g., osmotic shocks, acid shock, and exposure to toxic chemicals, this bacterial strain did not show the reliable correlation between CFU and RLU. These results might not suggest the direct estimation of bioiuminescence from the stressed bacteria be an index of both the survivalship and its activity. However, when the stressed bacterial cells were incubated under the favorable condition by relieving from the existing stress, the potential bioiuminescence (the lag periods before the increase of bioiuminescence, the increase rates of bioiuminescence, and the maximal levels of bioiuminescence) was shown to be highly dependent upon the strengths of the stresses exposed to the bacterial cells. Therefore, analysis of the potential bioiuminescence from the stressed bacteria revealed good relationships with survival as well as activity.

• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.55-62
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• 2023

This study aimed to investigate the effect of a coating agent on pork storage. Pork was coated with a coating agent containing sodium carboxymethyl cellulose (CMC) and mandarin peel powder (M). The treatments were divided into control, a 0.1% CMC treatment, and a 0.1% CMC +5% M treatment, and pH, color, 2-thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen (VBN), and the number of viable cell counts were measured. In the case of redness (a), it was found that the reduction over the storage period was less in the 0.1% CMC + 5% M treatment than in the control and the 1% CMC treatment. When stored at 4℃ and 25℃, TBARS of pork tended to increase during the storage period, followed by control, 0.1% CMC treatment, and 0.1% CMC + 5% M treatment, indicating that lipid oxidation was most suppressed in pork coated with mandarin peel powder. As a result of measuring the VBN of pork stored at 4℃ and 25℃, the 0.1% CMC + 5% M treatment showed lower values than the control and 0.1% CMC treatment. When the film-coated pork was stored at 4℃, the number of viable cell counts in the 0.1% CMC +5% M treatment area was 7.13±0.96 log CFU/g on the 12th day of storage, delaying the growth of viable cell counts for approximately 3 d more than other treatments. Therefore, coating pork with a film containing CMC and mandarin peel powder has been confirmed to delay the increase in the number of viable cell counts while reducing the quality change during pork storage, which is an effective alternative to improving the storage of fresh food as an edible film.

• Journal of Periodontal and Implant Science
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• v.48 no.3
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• pp.164-173
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• 2018

Purpose: The aim of this study was to evaluate the antimicrobial effect of a newly devised toothbrush with light-emitting diodes (LEDs) on Porphyromonas gingivalis attached to sandblasted and acid-etched titanium surfaces. Methods: The study included a control group, a commercial photodynamic therapy (PDT) group, and 3 test groups (B, BL, and BLE). The disks in the PDT group were placed in methylene blue and then irradiated with a diode laser. The B disks were only brushed, the BL disks were brushed with an LED toothbrush, and the BLE disks were placed into erythrosine and then brushed with an LED toothbrush. After the different treatments, bacteria were detached from the disks and spread on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy was performed to visualize bacterial alterations. Results: The number of viable bacteria in the BLE group was significantly lower than that in the other groups (P<0.05). Scanning electron microscopy showed that bacterial cell walls were intact in the control and B groups, but changed after commercial PDT and LED exposure. Conclusions: The findings suggest that an LED toothbrush with erythrosine treatment was more effective than a commercial PDT kit in reducing the number of P. gingivalis cells attached to surface-modified titanium in vitro.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.169-177
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• 1983

1. At selected time intervals, viable cell plate counts were run. After the 12 hours incubution the number of viable cells was maximum. 2. The morphology of L. acidophilus in tomato juice was thicker rods than those of in milk media. 3. In the assay of antimicrobial activity; (1) The antimicrobial activity of acidophilus tomato juice showed bigger inhibitory zone than acidophilus milk in the well-cup assay technique. (2) The inhibitory zone against Shigella dysenteriae was the biggest among the other pathogenic organisms in the disc assay. 4. The antimicrobial activity of sephadex G-50 gel filtration chomatography showed in the 5th fraction. 5. The spectra of ultraviolet absorption exhibited around maximum peak at 270nm.

• The Korean Journal of Food And Nutrition
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• v.21 no.3
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• pp.288-292
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• 2008

To save cost and time in Kimchi manufacture, the use of raw red-pepper paste and device-mashed vice materials, in place of dried red-pepper powder, was examined. Two kinds of Kimchi were prepared: One with dried red pepper powder and device-not mashed vice materials and the other with raw red pepper paste and device-mashed vice materials. Then pH, total acidity, total viable cell counts, total lactic acid bacteria and sensory characteristics were evaluated. Comparisons of the two Kimchis, indicated that changes in pH, total acidity, the total number of viable cells and total lactic acid bacteria were similar between the two groups. The acceptability score of the Kimchi made using the raw red pepper paste and device-mashed vice materials was slightly lower than that of Kimchi made using the dried red-pepper powder. This color was indistinctly changed since the vice materials were mashed and mixed. In conclusion, the results indicate that when manufacturing Kimchi using device-mashed vice materials, Kimchi of better quality can be made by adding dried red-pepper powder.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.96-100
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• 2001

Mixtures prepared from whole milk with added skin milk powder(2.5%, w/v) and Angelica keiskei juice (1.5%, w/v) were fermented with lactic acid bacteria (single and mixed culture of Lactobacillus bulgaricus and Strpetococcus thermophilus) for 24 hours. The fermented mixtures (curd yogurt) were evaluated for acid production (pH and titratable acidity), cell numbers, viscosity, sensory property and keeping quality. Results indicated that the addition of Angelica keiskei stimulated the acid production by lactic acid bacteria. The number of viable cells reached 4.5~7.3$\times$10$^{9}$ CFU/mL for Angelica keiskei-added yogurts, while 3.3~5.1$\times$10$^{9}$ CFU/mL for control yogurts. Viscosity of Angelica keiskei-added yogurts was higher (3,609~3,854 centipoises) than that of control yogurts(3,346~3,700 centipoises). Of the microorganism tested, mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus was most effective in acid production. The overall sensory score showed that Angelica keiskei yogurt fermented with Streptococcus thermophilus was evaluated as good as control yogurt. When yogurts were stored at 4$^{\circ}C$ for 12 days, pH, titratable acidity and viable cells of lactic acid bacteria were not significantly changed(p<0.05).

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.49-55
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• 2001

For the production of probiotic feed enriched with viable yeasts, aerobic liquid culture of Kluyveromyces marxianus was attempted in pulverized residual food wastes. After the preliminary shaking culture result, the liquid food wastes was added with urea($0.5g/{\ell}$), o-phosphate($0.4g/{\ell}$ ), molasses($4g/{\ell}$), and yeast extract($1g/{\ell}$), and the fermentation was carried out in 2-litre jar fermenter. In 12 hours of aerobic mixed culture with Aspersillus oryzae, viable cell count of the yeast reached to the number of $1.4{\times}10^{10}/{\ell}$ in the cultured medium.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.746-752
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• 2002

The purpose of the present study was to examine the antagonistic activities of Enterococcus faecalis strain PL9003 (PL9003) on Helicobacter pylori. This strain was isolated from infant feces and found to inhibit both the growth of H. pylori and its in vitro adherence to the human gastric cell line MKN-45. The binding of PL9003 to MKN-45 was observed under a light microscope after Cram staining and under a scanning electron microscope. When detected with an FITC-conjugate antibody, both viable and nonviable PL9003 were found to decrease the number of H. pylori bound to MKN-45. When detected by an enzyme-linked immunoabsorbent assay, about 70% of the H. pylori bound on MKN-45 disappeared with the four-1314 addition of viable or nonviable PL9003. The spent culture supernatant (SCS) of PL9003 also decreased the viability of H pylori even after neutralization and pepsin treatment. The above results suggest that PL9003 has a potential as a new probiotic for the stomach.

• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.447-454
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• 1999

Ginseng-vinegars were produced by the fermentation of 5% ethanol solution contained ginseng, red ginseng, ginseng marc and red ginseng marc using Acetobacter aceti 3281 for 26 days at 35$^{\circ}C$. The ginseng and red ginseng vinegar contained 0.236mg/ml of total sugar 0.236mg/ml of reducing sugar and 0.05% of ethanol and 1.005 of specific gravity 8,58CFU of viable cell count 3,24 of pH and 5.11% of acidity. Whereas the vinegars produced using the water-extracted red ginseng marc and the ethanol-extracted red ginseng marc were consisted of total sugar was 1.27mg/ml and 1.60mg/ml reducing sugar was 0.077mg/ml and 0.725mg/ml specific gravity was 1.001 and 1.004 the number of viable cells was 8.51CFU/ml and 8.1CFU/ml pH was 2.81 and 2.89 acidity was 5.18% and 5.32% respectvely ethanol concentration was 0.05% in both cases. In five-grade scoring test of sensory evaluation, it was estimated favorable that each vinegar made by were-extracted red ginseng marc, ethanol-extracted red ginseng marc ginseng and red ginseng ginseng from 0.5 to 32% of water-and ethanol-extract red ginseng was extracted with 10% white vinegar for 30 days. The best sensory vinegars were obtained that ginseng of 0.4~1.6% above red glnsend of 0.8% water-extracted red ginseng marc of 0.8~1.6% and ethanol-extracted red ginseng marc of 0.4~1.6% added in 10% white vinegar respectively.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.51-55
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• 2010

A lactic acid bacterial strain showing fast growth and high acid production in Korean pear puree was isolated from Kimchi. This strain was analyzed by API 50 CHL kit and 16S rRNA sequencing analysis and identified as Leuconostoc (Ln.) mesenteroides KACC 91495P. Korean pear puree was fermented using Ln. mesenteroides KACC 91495P strain at $30^{\circ}C$ for 18 h. The changes of pH, titratable acidity and viable cell number during fermentation were investigated. The pH and titratable acidity were reached to pH 3.86 and 1.09% after 18 h fermentation, respectively. The viable cell population of Ln. mesenteroides KACC 91495P was rapidly increased to $2.0{\times}10^9\;CFU/g$ during the 9 h of cultivation. The contents of lactic acid, acetic acid and malic acid were determined to be 0.213, 0.259, and 0.217% after 18 h fermentation, respectively. The content of polyphenolic compounds, known as antioxidants, in pear puree were enhanced by Ln. mesenteroides KACC 91495P cultivation. The level of total polyphenolic compounds was increased to around 140% of initial concentration. When the fermented pear puree was kept at $4^{\circ}C$, pH, titratable acidity and number of viable cells population were nearly maintained for 13 days.