• Korean Journal of Microbiology
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• v.3 no.1
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• pp.7-10
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• 1965

Higher number in colony counts in coliforms, total aerobes, and anerobes was obtained from marketable soy-bean mash than front that in fermented tank. The ratio between coliform contamination and total viable cells was higher in red pepper mash than in soy-bean mash. E. coli, contaminated in soy-bean mash persisted longer at low temperature ($0^{\circ}C$-$^5{\circ}C$) than at room temperature and they vanished after seven days of storage at room temperature. At 30.deg.C and 35.deg.C, these organisms were more effected than at room temperature. E. coli cells, inoculated in red pepper mash, were not recovered at room temperature after five days incubation. Soy-bean mash, completely fermented at normal conditions, were detected to contain $10^8$- $10^9$ organisms per gram of sample. On the contrary, marketable soy-bean mash were found to have more than 10$^{9}$ per gram samples. Since samples were found to have more than $10^9$ aerobes and anaerobes per gram, contamination of coliforms seemed to be apparent.

• KSBB Journal
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• v.32 no.3
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• pp.193-198
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• 2017

Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. ${\alpha}2,6$-Sialyltransferase (ST), which plays a key role in the attachment of ${\alpha}2,6-sialic$ acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of ${\alpha}2,6-ST$ can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as ${\alpha}2,6-ST$. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and ${\alpha}2,6-sialic$ acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of ${\alpha}2,3-sialic$ acid in wild type cells, 70.9% of total sialylated N-glycans were composed of ${\alpha}2,6-sialic$ acid in transfected cells. In conclusion, overexpression of ${\alpha}2,6-ST$ in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of ${\alpha}2,6-sialic$ acid, which is more resemble to human-like structure of glycosylation.

• Journal of the Korean Society of Food Culture
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• v.25 no.1
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• pp.76-81
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• 2010

This study was conducted to evaluate the influence of Lactobacillus bulgaricus and/or Sterptococcus thermophilus on the fermentation of yoghurt containing 5% (w/v) buckwheat sprouts. The results revealed that after 12 hours of fermentation the appropriate pH, titratable acidity and number of viable cells were attained. At that time, the rutin content of the buckwheat sprout-added yoghurt prepared by the mixed culture method was not changed, but the quercetin content increased greatly. Conversely, the rutin content of yoghurt that only contained Streptococcus thermophilus was decreased while the quercetin content was increased. The total phenol contents as well as the DPPH radical scavenging activities of both the mixed culture and Streptococcus thermophilus yoghurt did not differ significantly. Taken together, the results revealed that the use of a mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus during the preparation of buchwheat sprout-added yoghurt was desirable due to the decrease in pH and increase in titratable acidity and viable cells that occurred after 12 hr of fermentation. Moreover, phytochemicals in buckwheat sprouts such as rutin, quercetin and phenol compounds were comparatively increased during fermentation and influenced the antioxidant activity in buckwheat sprout-added yoghurt.

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.87-92
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• 1978

Extensive studies on the commercial fermented milks, which had been distributed over four months from July to October in 1978, were carried out for their microbial characterization including an investigation on the variations of bacterial populations under various storage conditions. 1. Total number of viable cells in the products were in between $5{\times}10^7$ cells/ml and $73{\times}10^7$ cells/ml, and $62{\times}10^7$ cells/ml, however no coliform bacteria were detected in the products. 2. Acidities of the products were not very high but fit in the standard as appeared to be in between 0.4869% and 0.6689%. 3. The acidities of the products showed little changes when stored at $5^{\circ}C$, but rises in 22.55% at $20^{\circ}C$ and in 117.66% at $30^{\circ}C$. 4. Total viable counts weren't varied much upto 96 hours when stored at $5^{\circ}C$, but increased during first 24 hours then decreased gradually at the higher temperatures. 5. Viable counts of lactic acid bacteria were decreased markedly with ascending the storage temperature, showing minimal variations when stored at $5^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.780-785
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• 1999

The effect of addition in different amounts of leek(4, 8, 12% respectively) during fermentation of kimchi was investigated. Fermentation characteristics such as pH, acidity and total reducing sugars as well as microbiological properties were determined. During fermentation, pH was more slowly lowered in kimchi added with leek than in control and titrable acidity of these kimchi was lower than that of control. Viable cells of total bacteria and lactic acid bacteria in these kimchi were higher than that of control during fermentation. Content of total reducing sugars was higher than that of control. Three kinds of reducing sugars such as fructose, glucose and galactose were detected and the dominant one appeared to be fructose. These results suggested that addition of leek seems to retard fermentation of kimchi due to their anti microbial actvity.

• 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 Dairy Science and Biotechnology
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• v.41 no.4
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• pp.211-218
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• 2023

This study aimed to identify lactic acid bacteria isolated from eight fermented milk products in Iran. We enumerated Lactobacillus species using De Man-Rogosa-Sharpe (MRS)-maltose and MRS agar with pH adjusted to 5.2, as well as assessment at 37℃ for 48 hr, studied Streptococcus spp. using M17 agar at 43℃ for 24 hr, and assessed Bifidobacterium species using nalidixic acid, paromomycin sulfate, neomycin sulfate, and lithium chloride (BL-NPNL) agar at 37℃ for 48 hr. The total viable Streptococcus spp. cell in fermented milk varied at 4.73-8.83 log CFU/mL. However, Bifidobacterium spp. were not detected in any of the tested samples. Lactobacilli were not detected in four of the eight samples, and viable Lactobacilli cells in the remaining four samples ranged 2.48-3.85 log CFU/mL. The pH of the tested samples ranged 3.53-4.19, and soluble solids (Brix measurement) ranged 7.5%-17.9%. A total of 130 isolates of gram-positive catalase-positive bacteria were characterized at the species level using 16S rRNA sequencing. Sequence analysis identified six species: Streptococcus thermophilus, Lactobacillus delbrueckii subsp. sunkii, Lactobacillus delbrueckii subsp. indicus, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Levilactobacillus brevis.

• KSBB Journal
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• v.14 no.5
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• pp.523-527
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• 1999

A naturally luminescent bacterium, Photobacterium phosphoreum was stored in 2.5% NaCl solution at 2$0^{\circ}C$, 4$^{\circ}C$, -2$0^{\circ}C$ and -7$0^{\circ}C$ for 30 days. In vivo luminescence and concentrations of total and culturable cells were determined by luminometer, spectrophotometer and dilution plate counting, respectively. When stored at 4$^{\circ}C$ and 2$0^{\circ}C$, concentrations of cells were rapidly decreased as a result of cell lysis, leading to adrop in turbidity and cultured counts. The bioluminescence of cells stored at 4$^{\circ}C$ was maintained until 12 days while those of cells starved at other temperatures decreased to background level within 3 days. Following incubation of stored cells in fresh liquid medium, activities of viable cells increased throughout storage period excepting cells stored at 2$0^{\circ}C$. Changes in bioluminescence intensity following addition of 2.5% NaCl solution markedly showed in cells stored at -2$0^{\circ}C$ and -7$0^{\circ}C$ and increased to maximum 8 fold.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.181-187
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• 1995

The cells of Vibrio vulnificus can be induced to the viable but nonculturable (VBNC) state by natural environmental parameters. The V. vulnificus cells in the VBNC state can not be recovered by ordinary laboratory techniques. This nonculturability could often hamper development of effective processing strategies to minimize the number of V. vulnificus in seafoods. Even with V. vulnificus cells in a culturable state, the length of time required to identify the bacteria in contaminated food by phenotyphic characterization may prevent appropriate in-time responses by public health agencies to infections of the bacteria. In the present study, we used polymerase chain reaction (PCR) to develop a rapid and direct detection method for V. vulnificus in small octopus (Octopus variabilis) which is consumed as a raw food in Korea. The region targeted was a 704-base pair (bp) portion of the hemolysin gene, vvhA, of V. vulnificus. The primers designed for PCR amplification were specific for all V. vulnificus sp. tested. Several methods were examined to extract total DNA directly from V. vulnificus seeded into the octopus homogenate and the guanidine isothiocyanate (CITC) method appeared to be most effective. From the octopus homogenate seeded by V. vulnificus at an initial level of $10^2$ CFU/ml of the homogenate and then incubated for 12 h, the targeted sequence was successfully amplified by PCR and the 704-bp DNA fragment was observed by gel electrophoresis. The total completion of this assay requires less than one day.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.49-54
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• 2010

The aim of this research was to estimate the effect of temperature and develop predictive models for the growth of total viable cells (TVC) and Escherichia coli (EC) on chicken breast under aerobic and various temperature conditions. The primary models were determined by Baranyi model. The secondary models for the specific growth rate (SGR) and lag time (LT), as a function of storage temperature, were developed by the polynomial model. The initial contamination level of chicken breasts was around 4.3 Log CFU/g of TVC and 1.0 Log CFU/g of E. coli. During 216 h of storage, SGR of TVC showed 0.05, 0.15, and 0.54 Log CFU/g/h at 5, 15, and $25^{\circ}C$. Also, the growth tendency of EC was similar to those of TVC. As storage temperature increased, the values of SGR of microorganisms increased dramatically and the values of LT decreased inversely. The predicted growth models with experimental data were evaluated by $B_f$, $A_f$, RMSE, and $R^2$. These values indicated that these developed models were reliable to express the growth of TVC and EC on chicken breasts. The temperature changes of distribution and showcase in markets might affect the growth of microorganisms and spoilage of chicken breast mainly.