• Korean journal of food and cookery science
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• v.14 no.1
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• pp.97-105
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• 1998

This study was carried out in order to standardize the processing method of spiced soy sauce, to get the sensory scores for organoleptic properties in different cooking of each food items, and to analyze the microbiological and chemical properties during storage periods. In determining the optimum conditions for standardizing of spiced soy sauce, the best sensory score was found in the ratio of soy sauce to sugar of 1:0.7. In the result of microbial experiment on standardized spiced soy sauce, the stability of storage at 40$^{\circ}C$ up to 6 weeks was proved. The standardized spiced soy sauce which was composed of about 45.5% water, 6% crude protein, 11.7% reducing sugar and 32.1% invert sugar has not shown any significant difference during storage for 6 weeks at 40$^{\circ}C$ compared with the state immediately after processing. In the test of saltiness, specific gravity, viscosity and Hunter's color value, there was no notable change during storage at 40$^{\circ}C$. In the experiment of free amino acid and total amino acid, main amino acids were glutamic acid and aspartic acid, which were not significantly changed during storage compared with processing state. In the analysis of mineral contents, sodium accounts for 95% of the total minerals, followed by phosphorus, magnesium, etc., in order, and there was no change during storage.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.45-50
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• 2003

The diversity and change of microbial communities during kimchi fermentation at $4^{\circ}C$ were analyzed by denaturing gradient gel electrophoresis (DGGE). Kimchi samples were taken every 5 days over the fermentation periods (for 60 days) to extract total DNA for DGGE analysis. Touchdown polymerase chain reaction was performed to amplify the V3 region of 16S rRNA gene. Sequencing results of partial 16S rDNA amplicons from DGGE profiles revealed that lactic acid bacteria (LAB), especially Weissella koreensis, Lactobacillus sakei and Leuconostoc gelidum were dominants in kimchi fermentation at $4^{\circ}C$. And we knew that W. koreensis steadily existed throughout the whole fermentation period, also Lb. sakei and Leuc. gelidum appeared from 10th day and 30th day of fermentation time, respectively and then these species were to be dominant microorganisms.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.172-177
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• 2004

Photosynthetic bacteria, Rhodospirillum rubrum, have been reported to change their metabolic patterns depend-ing on the light condition. The genetic approach for such a metabolic change is one of main subject in pho-tosynthetic bacteria. It has been reported that the extrachromosomal plasmid might be related to this metabolic regulation. In this study, we have determined the partial sequences of R. rubrum plasmid pKYl with HindIII fragments and the predicted pKYl ORFs and physical map. We found the 8 putative proteins related to the genetic recombination of bacterium, which is reported to the alternative gene expression. Our results suggest that the genes located in pKYl are possibly involved in the metabolic switch according to the photocondition.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.334-344
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• 2014

The objective of this study was to evaluate the microbiological and physicochemical characteristics, and the antagonistic activity against Helicobacter pylori ATCC 43504, of yogurt fermented with the lactic acid bacteria from Baikkimchi kept under cold storage. The viable cell counts, titratable acidity, viscosity, and total solid content of the yogurt were different according to the bacterial strains used for fermentation. There was no significant change (P>0.05) in the various properties of refrigerated yogurt. Among the tested strains, the strongest resistance against artificial gastric juice and bile salt was found for Lactobacillus brevis BK11 and Lactobacillus paracasei BK57. Due to high lactic acid levels obtained from these two lactic acid bacteria, yogurt may show good anti-Helicobacter effects according to the time-kill assay. In particular, yogurt fermented with L. brevis BK11 significantly reduced the number of H. pylori adhering to gastric epithelial AGS cells and the urease activity of this pathogen (P<0.05).

• Journal of Microbiology
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• v.44 no.5
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• pp.480-491
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• 2006

As part of the long-term monitoring projects on Antarctic terrestrial vegetation in relation to global climate change, a lichen floristical survey was conducted around the Korean Antarctic Station (King Sejong Station), which is located on Barton Peninsula, King George Island, in January and February of 2006. Two hundred and twenty-five lichen specimens were collected and sixty-two lichen species in 38 genera were identified by morphological characteristics, chemical constituents, TLC analysis and ITS nucleotide sequence analysis.

• Journal of Microbiology
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• v.44 no.1
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• pp.50-53
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• 2006

Cys-29 and Cys-251 of Streptomyces albus valine dehydrogenase(ValDH) were highly conserved in the corresponding region of $NAD(P)^+$-dependent amino acid dehydroganase sequences. To ascertain the functional role of these cysteine residues in S. albus ValDH, site-directed mutagenesis was performed to change each of the two residues to serine. Kinetic analyses of the enzymes mutated at Cys-29 and Cys-251 revealed that these residues are involved in catalysis. We also constructed mutant ValDH by substituting valine for leucine at 305 by site-directed mutagenesis. This residue was chosen, because it has been proposed to be important for substrate discrimination by phenylalanine dehydrogenase (PheDH) and leucine dehydrogenase (LeuDH). Kinetic analysis of the V305L mutant enzyme revealed that it is involved in the substrate binding site. However it displayed less activity than the wild type enzyme toward all aliphatic and aromatic amino acids tested.

• Korean Journal of Microbiology
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• v.20 no.3
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• pp.105-112
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• 1982

The strain of Aspergillus, 6368A, producing acid protease showing high activity was isolated from soil, as a result of wide research about mold group. This strain was identified as a species of Aspergillus tubingensis by the investigation of morphological characteristics. The change of the enzyme production under the various media and culture condition was also studied. The optimum pH and stability of crude acid protease are 2.5, 2.0~4.5 and the optimum temeprature and thermal inactivation waas shown $50^{\circ}C,\;55^{\circ}C$, respectively. From the result of the study on the effects of metal ions, it was found that $MnCl_2,\;CoCl_2,\;CuCl_2,\;SrCl_2,\;and\;NiCl_2$ slightly increased the enzyme activity, on the other hand $ZnCl_2,\;CaCl_2,\;MgCl_2,\;SLS,\;and\;KMnO_4$ decreased it.

• Korean Journal of Microbiology
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• v.12 no.1
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• pp.37-51
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• 1974

Three strains which accumulated large quantities of L-hlutamic acid as the chief product of metabolism in the presence of glucose and inorhanic ammonium salt under the aerobic condition sere newly isolated. These strains have the general characters as follows: Gram-positive, short fod-shaped, non-sporulating, non-motile, and facultative anaerobe. A change of cell shates was not almost observed in their life cycles and neither a phenomenon of cell-elongation nor a pleomorphism was recognized in any cases. Together with rigid stability in Gram-stain, these characters as above indicated evidences that newly isolates would belong to genus Brevibacterium clearly differentiated from genus Corynebacterium. At the same time the newly isolates, in addition to nutritional requirement of biotin and thiamine, showed the distinctive character of requirement of special amino acid such as histidine or cysteine for their considerable growth. These physiological characters including nitrates reduction, reaction on milk, and slow formation of acid from sugar also were useful in confirming that these bacteria would be Brevibacterium ammoniagenes.

• Journal of the Korean Society of Fashion and Beauty
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• v.6 no.2
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• pp.73-79
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• 2008

To study of the rate of damage and morphological change when apply perm and dye according to kinds of curly hair, measured the thickness of hair and divided the samples into groups. Measured the chromaticity and thickness according to kinds of curly hair and chemical treatment with Spectrum colormeter and Micrometer. Measured the tensile strength of hair then calculated the damage rate. After tensile test, took photographs of the section and surface with the electron microscope.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.696-702
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• 1994

An interspecific fusant strain, MS1, was obtained by protoplast fusion between S. peucetius subsp. caesius and S. platensis. We studied on the microbiological and cultural characteristics of the fusant MS1. In liquid culture, the viscosity of culture broth of S. peucetius increased during incubation However the fusant MS1 formed pellet like S. platensis without viscosity change. On agar medium the colony morphology of MSI resembled S. platensis but the color was similar to S. peucetius. The fermentation products of the fusant MS1 was identical with S. peucetius.