• Applied Biological Chemistry
• /
• v.23 no.2
• /
• pp.115-122
• /
• 1980

An attempt was made to isolate suitable kinds of fungi for the preparation of Sufu, one of the fermented soybean products, and also to investigate the chemical changes during the aging period of Sufu. 1. First, from the isolated fungi 14 strains of Mucor sp. were selected on the basis of their morphological texture and agreeable odor. Secondly, 7 strains of these fungi with relatively high proteolytic activity were selected. 2. All of the pehtzes that were fermented with the selected fungi have raised the water soluble protein content to about 10% on average. 3. The amount of hydrolyzed protein increased to the 18th. day and then did not show any visible increase during the aging period. Finally, the 3 strains of suitable fungi for preparing Sufu could be selected. It seemed that one of them was probably better than the other two which were almost same as the standard fungi, Actinomucor elegans, in protein hydrolyzation.

• Korean Journal of Microbiology
• /
• v.33 no.1
• /
• pp.38-42
• /
• 1997

For the purpose of obtaining microorganisms producing high amount of erythritol, the screening test was carried out. Productivity of erythritol was analyzed by paper chromatography and HPLC' methods. Among more than two hundred isolates, one strain(KJX1) was selected as an erythritol prtducer from thc soil of corn shock. The isolated strain was identified as Pmicilliurn sp. KJ81 from the morphological and physiological characteristics. Penicillium sp. KJ81 showed white to green colony color, two- to three-stage branching conidiophcvc and flask-shaped phialides.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.4
• /
• pp.801-804
• /
• 1999

Quality characteristics of yakju prepared by different yeast strains such as Saccharomyces cerevisiae S 2, Saccharomyces cerevisiae S 6 and Saccharomyces cerevisiae IFO 1950 were investigated during fermentation. The pH in all kinds of yakju was gradually decreased until 6 days and then it was constant. In stage of fermentation, acidity of yakju made of Saccharomyces cerevisiae S 6 was higher than others. At the beginning stage of fermentation, ethanol contents were in the range of 0~2% increased to 9.5~11.5% after 10 days. Yakju made of Saccharomyces cerevisiae S-2 showed higher ethanol contents than others. Free sugars in yakju were found to be glucose and maltose. The contents of free sugars were decreased until 6 days and they were not detected. The content of ethanol in yakju showed the highest value at the 6th day and those of yakju A, B and C were 11.9, 9.5, 10.9%, respectively. Main organic acids in yakju were citric acid and lactic acid. The content of citric acid in yakju B was higher than others.

• Microbiology and Biotechnology Letters
• /
• v.11 no.1
• /
• pp.67-74
• /
• 1983

The studies on the color improvement of the Doenjang (two types of fermented soybean paste : soybean Doenjang and modified Doenjang) using various Aspergillus oryzae strains (6 strains : A, B, C, D, E, F) were conducted with the series of experiments of enzymatic activities (pretense, $\alpha$-and $\beta$-amylase), browning color formation (Lovibond color), major chemical components (amino nitrogen, reducing sugar and others) and sensory evaluation (color, taste and odor). Aspergillus oryzae 2157 (C strain) had a high potential for the color improvement of Doenjang products and was identified as non-browning strain during Doenjang fermentation and storage period. And also this strain was appeared to be in good enzyme activities and flavor characteristics.

• Journal of Life Science
• /
• v.23 no.6
• /
• pp.796-803
• /
• 2013

Property changes and bacterial characterizations by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were investigated during the fermentation of Makgeollies by 5 isolated yeast strains. Changes of pH were large between day 0 (pH 6) and day 2 (pH 3) and showed less variation after then. ANOVA analyses revealed that pHs were statistically different with fermentation times (p<0.001), while strains (p=0.60) did not. Acidities were changed from 0.19 to 1.04% and showed rather high increase from day 2, and fermentation times (p<0.001) and strains (p=0.006) represented statistical differences. All strains showed less than 0.150% at amino-type nitrogen contents except S strain showed 0.442% at day 8, and there were no statistical differences with fermentation times (p=0.4558) and strains (p=0.3513). Saccharinities of C strain were higher from day 4, and fermentation times (p<0.0001) and strains (p=0.007) showed statistical differences. Large variation of alcohol concentrations (%) were observed between day 0 (0%) and day 2 (10%) and showed less variation after day 2, and there was no statistical difference with strains. Dominant prokaryotes were Lactobacillus fermentum and Pediococcus pentosaceus, which producing acids and functional materials. Dominant eukaryote was Saccharomyces cerevisiae, which might be resulted from addition of yeasts.

• The korean journal of orthodontics
• /
• v.27 no.2
• /
• pp.173-180
• /
• 1997

The purpose of this study was to evaluate the effectiveness of chlorhexidine varnish treatment in the prevention of dental caries in orthodontic patients by observing microbial change in dental plaque after varnish treatment. The sample consisted of 26 patients who were classified into an experimental group and a control group, 13 patients each. The experimental group was treated with chlorhexidine varnish once a week for 4 weeks. The control group was treated with placebo varnish using the same procedure, The microbial change was analysed by indirect immunofluorescene technique before treatment and 4 weeks, 8 weeks after treatment. The results were as follows. 1. Streptococcus mutans were strongly suppressed until 8 weeks after chlorhexidine varnish treatment(p<0.01). 2 The proportion of Streptococcus sanguis increased temporarily 4 weeks after chlorhexidine varnish treatment(p<0.05), decreased to original level after 8 weeks. 3. Streptococcus mitts, Actinomyces viscosus, Actinomyces naeslundii did not show significant change after chlorhexidine varnish treatment.

• Journal of Convergence for Information Technology
• /
• v.11 no.5
• /
• pp.223-231
• /
• 2021

The antioxidant activity of Chrysanthemum indicum L. extract (CIL) was investigated by fermenting lactic acid bacteria with the CIL from 64% and 80% ethanol extraction and measuring the total phenolic contents (TPC), flavonoid, 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power (RP), and linoleic acid auto-oxidation inhibitory activity. CIL was confirmed to inhibit bacterial auto-oxidation. TPC was increased in strains 3109 and 3237, while flavonoid decreased in all strains. DPPH was increased in strains 3074 and 3109 fermented with 64% CIL and all the strains with 80% CIL. RP was increased and linoleic acid auto-oxidation inhibitory activity decreased in all the strains fermented with 64% or 80% CIL. Among the 4 strains, strain 3109 had the highest DPPH and RP; thus, it was most effective in increasing CIL's antioxidant efficacy through the fermentation process.

• Food Science of Animal Resources
• /
• v.26 no.4
• /
• pp.503-510
• /
• 2006

Survival and stability of 19 bifidobacterial strains included 13 isolates from Korean infants against acid, bile acid and oxygen exposure were examined. Acid resistance of selected strains at pH values of 4.0, 3.0 and 2.0 was tested. Among the bifidobacterial strains tested, B. bifidum B3, B. longum D6, and B. adolescentis F1 exhibited higher viable cell counts exposed to acid whereas other strains had various results. The abilities of the strains to grow in the MRS broth containing 0.2% thioglycolic acid and 0.2% oxgall were tested and the tolerance of B. bifidum B3 and B. longum D6 to bile acid were higher than that of others. Even though in same species, the tolerance of tested strains to bile acid were variable. Stabilities of tested strains to oxygen exposure were variable and B. bifidum and B. longum strains showed relatively higher viable cell counts after 48 hours exposure to aerobic incubation. These results demonstrated that the survival and stability of bifidobacterial strains to acid, bile acid, and oxygen exposure were variable and strain-dependent. Due to their tolerant ability to environmental factors like acid, bile acid, and oxygen, B. bifidum B3 and B. longum D6 had good potential properties as probiotic cultures and may be useful for industrial application.

• Korean Journal of Microbiology
• /
• v.54 no.4
• /
• pp.343-353
• /
• 2018

Our previous research demonstrated the essential role of the xenB gene in stress response to RDX by using Pseudomonas sp. HK-6 xenB knockout. We have extended this work to examine the cellular responses and altered proteomic profiles of the HK-6 xenA knockout mutant under RDX stress. The xenA mutant degraded RDX about 2-fold more slowly and its growth and survival rates were several-fold lower than the wild-type HK-6 strain. SEM revealed more severe morphological damages on the surface of the xenA mutant cells under RDX stress. The wild-type cells expressed proportionally-increased two stress shock proteins, DnaK and GroEL from the initial incubation time point or the relatively low RDX concentrations, but slightly less expressed at prolonged incubation period or higher RDX. However the xenA mutant did not produced DnaK and GroEL as RDX concentrations were gradually increased. The wild-type cells well maintained transcription levels of dnaA and groEL under increased RDX stress while those in the xenA mutant were decreased and eventually disappeared. The altered proteome profiles of xenA mutant cells under RDX stress also observed so that the 27 down-regulated plus the 3 up-regulated expression proteins were detected in 2-DE PAGE. These all results indicated that the intact xenA gene is necessary for maintaining cell integrity under the xenobiotic stress as well as performing an efficient RDX degradation process.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.233-233
• /
• 1996

배지의 영향에 대하여 검토하기 위하여 SDA, MHA, NA 및 BHIA를 사용하였으며, 시험균주 중 Pseudomonas aeruginosa에 대하여만 NA에서의 MIC 값이 낮게 나타났을 뿐 나머지 균주에 대하여는 배지에 따른 항균력 변화가 관찰되지 않았으며, 배지의 pH를 5.4-8.4까지 변화시켰을 때 pH 변화에 따른 DA-1131의 유의적인 항균력 변화와 접종균량에 따른 항균력 변화가 관찰되지 않았다. Methicillin-resistant Staphylococcus aureus(MRSA)에 대하여는 DA-1131과 vancomycin 간의 상승 및 상가작용이 관찰되었고, P. aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae 및 Serratia marcescens 등의 균종에 대하여는 ciprofloxacin의 상가작용이 확인되었다. Sisomicin은 P. aeruginosa에 대한 상승 및 상가작용이 인정되었으나 ceftazidime은 DA-1131에 의한 길항작용이 관찰되었다.