• Journal of Dairy Science and Biotechnology
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• v.41 no.2
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• pp.76-85
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• 2023

This study investigated the effect of the addition of pomegranate concentrate to yogurt on the growth of pathogenic and lactic acid bacteria. The concentration of the MRS broth was adjusted to one-half and used for an experiment. Pomegranate concentrate was added at concentrations of 4%, 2%, 1%, and 0.5%, which significantly promoted the growth of Lacto-coccus cremoris, Weissella cibaria, Weissella paramesenteroides, Lactobacillus plantarum, Lactobacillus acidophilus, Streptococcus thermophillus, Lactobacillus bulgaricus, and Lactobacillus lactis. The growth of lactic acid bacteria increased with higher concentrations of pomegranate. However, the addition of pomegranate concentrate inhibited the growth of Escherichia coli KCCM11587, E. coli KCCM11591, E. coli KCCM11596, and E. coliKCCM11600. Yogurt with added pomegranate concentrate demonstrated optimal conditions compared to that of the control without the addition. Particularly, the viable cell count of lactic acid bacteria was significantly higher in the yogurt with pomegranate concentrate. Furthermore, the viability of the lactic acid bacteria in the yogurt with pomegranate concentrate was higher than that of the control without the addition of concentrate during storage.

• Journal of Life Science
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• v.33 no.7
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• pp.538-548
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• 2023

The research has been conducted on the isolation of antimicrobial compounds from plant natural extracts and their potential application in oral health care products. This study aimed to investigate the antimicrobial mechanism by analyzing the changes in gene expression of Streptococcus mutans, a major oral pathogen, in response to complex compounds extracted from Aralia continentalis and Arctii Semen using organic solvents. Transcriptome analysis (RNA-seq) revealed that both natural extracts commonly upregulated or downregulated the expression of various genes associated with different metabolic and physiological activities. Three genes (SMU_1584c, SMU_2133c, SMU_921), particularly SMU_921 (rcrR), known as a transcription activator of two sugar phosphotransferase systems (PTS) involved in sugar transport and biofilm formation, exhibited consistent high expression levels. Additionally, component analysis of the A. continentalis extract was performed to compare its effects on gene expression changes with the A. Semen extract, and two active compounds were identified through gas chromatography-mass spectrometry (GC-MS) analysis of the active fraction. The n-hexane fraction (ACEH) from the A. continentalis extract exhibited antibacterial specificity against S. mutans, leading to a significant reduction in the viable cell counts of Streptococcus sanguinis and Streptococcus gordonii among the tested multi-species bacterial communities. These findings suggest the broad-spectrum antibacterial activity of the A. continentalis extract and provide essential foundational data for the development of customized antimicrobial materials by elucidating the antibacterial mechanism of the identified active compounds.

• Applied Biological Chemistry
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• v.14 no.2
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• pp.137-148
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• 1971

Studies were carried out to investigate the main fermentation microorganisms and their flora changes during Korean native soy-sauce fermentation. Korean native Maeju loaves collected from 5 Do's were separated into surface and inner parts. Four different soy-sauces-the surface part Maeju fermented soy-sauce, the inner part, the surface and inner part combined Maeju fermented soy-sauce, and the semi-Japanese type soy-sauce were fermented and the changes of fermentation microorganism flora and the various chemical components during the period of their fermentations were studied. Besides, 14 home-made soy-sauces collected from 14 different places all over Korea were examined in comparison with the laboratory soy-sauces and to determine the characteristics of Korean native soy-sauce. The results were as follows: 1. The main microorganisms in Korean native soy-sauce fermentation were determined as; Aerobic bacteria: Bacillus subtilis, Bacillus pumilus Lactic acid bacteria: Pediococcus halophilus, Leuconostoc mesenteroides Yeasts: Torulopsis datila, Saccharomyces rouxii 2. Microflora changes during Korean native soy-sauce fermentation were as follows; Aerobic bacteria increased until the 2nd week of fermentation and then gradually decreased. The lactic acid bacteria increased until the 3rd week, after which decreased. When the lactic acid fermentation lowered the pH value to below the 5.4, yeasts were able to grow and participate the fermentation. As the production of organic acids amounted, to a certain height, the growth of all microorganisms lead to the period of decline or death at about the 2nd month of fermentation. After boiling of soy-sauce most microorganisms except a few of Bacillus sp. disappeared. Occosionally yeasts and lactic acid bacteria survived depending upon the composition of soy-sauce. 3. Changes of general chemical components influencing the microflora were investigated for the period of Korean native soy-sauce fermentation. Tetal acidity, salt concentration and total nitrogen were increasing steadily over the entire period of fermentation. pH values were dropping to a certain degree of about 4.5. Salt concentration and pH value seemed to be the important factors influencing the microflora. 4. The microflora were influenced by chemical components of soy-sauce. Aerobic bacteria were able to survive in all soy-sauce as they made spores. Growth of lactic acid bacteria was inhited at 23-26% of salt concentration and pH 4.8. Soy-sauce yeasts started to grow only at pH below 5.4 and seemed to be inhibited at around 26% of salt concentration under pH 4.5-4.7. 5. The open kettle boiling of soy-sauce, the characteristic process of Korean native soy-sauce manufacturing, was effective to sterilize microorganisms, increase the salt concentration, and coagulate proteins. 6. The average viable cell counts of microorganism found in collected samples of home-made Korean native soy-sauces were; Aerobic bacteria: $53{\times}10^2\;cell/ml$ Lactic acid bacteria: 34 cell/ml Yeasts: 14 cell/ml The average values of chemical compositions of samples of home-made Korean native soy-sauce were; Salt concentration: 28.9% pH value: 4.79 Total acidity(lactic acid): 0.91g/100ml Total nitrogen: 1.09g/100ml

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1781-1786
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• 2011

This study was conducted to investigate the cause of microbiological contamination in yogurt and evaluate the effect of physicochemical treatment on the growth inhibition of Hanseniaspora uvarum isolated from yogurt. The yeast strain Hanseniaspora uvarum Y1 was subjected to heat and pH treatments. H. uvarum Y1 was killed at $70^{\circ}C$ and $80^{\circ}C$ after 15 min and survived in a wide pH range from pH 2 to 9. However, it did not survive under pH 1 and over pH 10. In a disk diffusion susceptibility test on H. uvarum Y1, a clear zone (5 mm) of growth inhibition was observed upon treatment with electrolyzed water. The effect of ozone gas on the growth of H. uvarum Y1 was evaluated by viable cell count. Initial cell numbers of $10^2$ and $10^3$ CFU/mL of H. uvarum Y1 were completely killed by treatment for 10 and 30 min, respectively. H. uvarum Y1 was also sterilized by microwave treatment for 1 min. When treated with gamma-irradiation, the rate of killing of H. uvarum Y1 was proportional to the irradiation dose. and complete killing occurred at a dose of 50 kGy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1436-1443
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• 2007

This study was conducted to investigate the shelf-life and quality of Takju added with Glycyrrhiza uralensis (GU), Menthae herba(MH), Schizandra chinensis(SC), and chitosan (C) during storage at $10^{\circ}C$ for 12 days. The viable cell and yeast cell numbers of the Takju treated with Schizandra chinensis powder (SCP) and C were moderately reduced compared with those of the standard. The SC and C Takju were shown to have the lowest oxidations. For turbidity, the SC and C Takju were the most stabilized. Among the treatments, sugar content, pH, and acidity showed no significant differences during storage. However, the lightness, yellowness, and redness value of all the samples were higher than those of the standard. In the sensory evaluation, the standard, SCP, and C scored comparatively higher than the other samples at 0 day. On the other hand, SC and C, GU+MH, and C scored higher after 9 days. From these results, treating Takju with SCP, GU, MH, SC, and C resulted in improvements with regards to its preservation and development of quality.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.589-600
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• 2001

Insulin-like growth factor I (IGF-I) has the local tissue regulating actions. In bone, IGF-I increases the replication of osteoblastic lineage, probably preosteoblasts, and enhances osteoblastic collagen synthesis and matrix composition rates. The purpose of this study was to investigate the local regulatory effect of IGF-I on periodontium totally, both in an autocrine and paracrine manner. To examine the effect of IGF-I directly on osteoblast (OB) of test rats, and indirectlv on OB via periodontal ligament fibroblast (PDLF), and the effect of gingival fibroblast (GF) on OB via cellular paracrine manner for the understanding of humoral action of adjacent tissue, GF and PDLF were obtained from male Sprague-Dawley rats of six to eight weeks of age. OB was obtained iron frontal and parietal calvarial bone of Sprague-Dawley 21day-old-fetus. After each tell was Incubated 24 hours, for collecting conditioned medium, different concentrations of IGF-I (1,10,100 ng/ml,1ml/well) was adding in the GF, PDLF cells, and the supernatant from these cultures was put into the primary OB culture with $1{\times}10^4$cell/ml/well. The experimental group was divided into six groups control OB, IGF-I treated OB, OB culture with conditioned medium from PDLF, OB culture with conditioned medium from IGF-I treated PDLF, OB culture with conditioned medium from GF, OB culture with conditioned medium from IGF-I treated GF. After final IGF-I treatment, OB was Incubated for 24 hours, and alkaline phosphatase activity assay, BMP expression, cell proliferation measurement using MTT assay, total protein measurement, Collagen synthesis assay using western blot, and examination of bone nodule synthesis were done. Alkaline phosphatase expressions were increased in the group of PDLF-IGF-I supernatant treatment. Direct IGF-I treatment with concentrations of 100ng/m1 showed increased viable tell number measured by MTT assay. And IGF-I treatment did not increase total protein amount. The entire experimental group showed BMP2, 4 expression in western blot, and there was no significant difference between control and experimental groups. These results suggested that supernatant from PDLF effects on increasing cellular activities of OB regardless of IGF-I, and at high concentration, IGF-I increases OB tell proliferation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.277-281
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• 1997

The cell density changes of Vibrio mimicus K-1 in sea water and arkshell feeding it were examined at various temperature. The strain was suspended in sterilized sea water and storaged at experimental temperature $(5,\;10,\;15,\;20,\;and\;28^{\circ}C)$). At intervals of up to 10 days, aliquots of each suspension were plated onto BHI agar. At 5 and $10^{\circ}C$, the plate counts of V. mimicus K-1 showed a rapid decline, which 3s known to be a reault of this bacterium's entering into the viable but non culturable state. At 20 and $28^{\circ}C$, however, V. mimicus K-1 are stable over the 10 days experimental periods. V. mimicus K-1 was fed to arkshell, which was subsequently stored at temperatures ranging from 5 to $20^{\circ}C$ for 10 days. The samples of arkshell were homogenized and plated at intervals to determine the cell density of V. mimicus K-1 and total aerobic population of bacteria present. At 5 and $10^{\circ}C$, the numbers of V. mimicus K-1 in sea water rapid decreased over the 10 days experimental periods. However, little change of V. mimicus K-1 density was observed in shellstock arkshell at 5 and $10^{\circ}C$. While, V. mimicus K-1 density was decreased more rapidly to level below limit of dectection in shucked arkshell at same temperature. Incubation at the higher temperature $(20^{\circ}C)$ resulted in large increase in total aerobic bacterial number of shellstock arkshell. These results suggest that even with proper storage, indigenous levels of V. mimicus may remain sufficiently high in shellstock arkshell to produce infection in compromise hosts.

• Journal of Chest Surgery
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• v.39 no.7 s.264
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• pp.520-526
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• 2006

Background: The clinical application of cryosurgery the management of lung cancer is limited because the response of lung at low temperature is not well understood. The purpose of this study is to investigate the response of the pulmonary tissue at extreme low temperature. Material and Method: After general anesthesia the lungs of twelve Mongrel dogs were exposed through the fifth intercostal space. Cryosurgical probe (Galil Medical, Israel) with diameter 2.4 mm were placed into the lung 20 mm deep and four thermosensors (T1-4) were inserted at 5 mm intervals from the cryoprobe. The animals were divided into group A (n=8) and group B (n=4). In group A the temperature of the cryoprobe was decreased to $-120^{\circ}C$ and maintained for 20 minutes. After 5 minutes of thawing this freezing cycle was repeated. In group B same freezing temperature was maintained for 40 minutes continuously without thawing. The lungs were removed for microscopic examination on f day after the cryosurgery. In four dogs of the group A the lung was removed 7 days after the cryosurgery to examine the delayed changes of the cryoinjured tissue, Result: In group A the temperatures of T1 and T2 were decreased to the $4.1{\pm}11^{\circ}C\;and\;31{\pm}5^{\circ}C$ respectively in first freezing cycle. During the second freezing period the temperatures of the thermosensors were decreased lower than the temperature during the first freezing time: $T1\;-56.4{\pm}9.7^{\circ}C,\;T2\;-18.4{\pm}14.2^{\circ}C,\;T3\;18.5{\pm}9.4^{\circ}C\;and\;T4\;35.9{\pm}2.9^{\circ}C$. Comparing the temperature-distance graph of the first cycle to that of the second cycle revealed the changes of temperature-distance relationship from curve to linear. In group B the temperatures of thermosensors were decreased and maintained throughout the 40 minutes of freezing. On light microscopy, hemorrhagic infarctions of diameter $18.6{\pm}6.4mm$ were found in group A. The infarction size was $14{\pm}3mm$ in group B. No viable cell was found within the infarction area. Conclusion: The conductivity of the lung is changed during the thawing period resulting further decrease in temperature of the lung tissue during the second freezing cycle and expanding the area of cell destruction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.991-995
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• 2013

This study was conducted to develop an edible culture media with various types of cereals and soybeans for the pre-cultivation of lactic acid bacteria (LAB). To manufacture the edible culture media, LAB enrichment media were prepared using cereals such as brown rice (including germinated brown rice, glutinous brown rice, and germinated glutinous brown rice), yellow soybeans (including yellow soybeans, hulled yellow soybeans, germinated yellow soybeans, hulled and germinated yellow soybeans), and black soybeans (black soybeans, hulled black soybeans, germinated black soybeans, hulled and germinated black soybeans). Seven species of LAB were used in the experiment: Lactobacillus (Lb.) farciminis, Lb. homohiochii, Lb. pentosus, Lb. plantarum, Leuconostoc (Leu.) paramesenteroides, Leu. citreum, and Leu. lactis. For edible culture media from cereals, the average viable cell count of the seven starter cultures was 7.6~8.0 log CFU/mL, while that of the MRS culture medium, a synthetic medium, was 9.2 log CFU/mL; thus proliferation was lower by about 1~2 log CFU/mL in starter cultures from cereals compared to the synthetic medium. In the case of the edible culture media from soybeans, most bacteria showed higher proliferation in the hulled and germinated soybean media. In particular, Lb. plantarum showed the highest cell count at 10.08 log CFU/mL. In the case of edible culture media from black soybeans, the proliferation rate was higher in the hulled and germinated black soybean medium. Lb. homohiochii showed the highest proliferation in the hulled and germinated black soybean medium at 9.90 log CFU/mL. All results show that edible culture media using cereals and soybeans are generally good for LAB. Especially, hulled and germinated black soybeans are optimal for the pre-cultivation of LAB medium.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.143-147
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• 1994

Four samples of commercially manufactured yogurts (plain, drinking type) were purchased and evaluated their physico-chemical properties, buffering capacity. And the survival rate of lactic acid bacteria and their ${\beta}-galactosidase$ activity under the acidic conditions (in vitro) were investigated. The values of pH, titratable acidity, viscosity and viable cell counts of yogurts were $3.71{\sim}4.08$, $0.990{\sim}1.045%$, $256{\sim}3164\;cps.$ and $10^8{\sim}10^9\;cfu/ml$, respectively. The volume of 1.0 M-HCl required to reduce the pH of yogurt (50 ml) to minus 2 value was $3.58{\sim}4.33\;ml$. When commercial yogurts were incubated at $37^{\circ}C$ for 120 minutes under the acidic conditions (pH 3.5, 2.5, 1.5), the survival rates of lactic acid bacteria in yogurt were $3.5{\times}10^{-2}{\sim}3.6{\times}10^{-1}%$ at pH 2.5, $8.3{\times}10^{-5}{\sim}4.2{\times}10^{-3}%$ at pH 1.5, respectively, but there was no significant difference at pH 3.5. The remaining activities of ${\beta}-galactosidase$ were $9.4{\sim}36.2%$ at pH 2.5, $4.2{\sim}19.0%$ at pH 1.5, respectively. These results suggested that a significant number of lactic acid bacteria in yogurt might be destroyed in the hostile environment of the stomach, but ${\beta}-galactosidase$ activity from yogurt might be somewhat maintained probably due to the protecting effect by its cell wall and membrane.