• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2090-2099
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• 2015

Recently, the cardiovascular disease has been widely problematic in humans probably due to fibrin formation via the unbalanced Western style diet. Although direct (human plasmin) and indirect methods (plasminogen activators) have been available, bacterial enzyme methods have been studied because of their cheap and mass production. To detect a novel bacterial fibrinolytic enzyme, 111 bacterial strains with fibrinolytic activity were selected from kimchi. Among them, 14 strains were selected because of their stronger activity than 0.02 U of plasmin. Their 16S rRNA sequence analysis revealed that they belong to Bacillus, Leuconostoc, Propionibacterium, Weissella, Staphylococcus, and Bifidobacterium. The strain B. subtilis ZA400, with the highest fibrinolytic activity, was selected and the gene encoding fibrinolytic enzyme (bsfA) was cloned and expressed in the E. coli overexpression system. The purified enzyme was analyzed with SDS-PAGE, western blot, and MALDI-TOF analyses, showing to be 28.4 kDa. Subsequently, the BsfA was characterized to be stable under various stress conditions such as temperature (4-40oC), metal ions (Mn²⁺, Ca²⁺, K²⁺, and Mg²⁺), and inhibitors (EDTA and SDS), suggesting that BsfA could be a good candidate for development of a novel fibrinolytic enzyme for thrombosis treatment and may even be useful as a new bacterial starter for manufacturing functional fermented foods.

• Journal of Microbiology and Biotechnology
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• 제6권4호
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• pp.238-244
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• 1996

$\gamma$-Glutamyl transpeptidase ($\gamma$-GTP; EC 2.3.2.2) present in the culture filtrate of Bacillus sp. KUN-17 was purified 400-fold through a consecutive procedure including organic precipitation and column chromatography. The enzyme has an estimated molecular weight of 70, 000 and consists of hetero-subunits with molecular weights of 42, 000 and 22, 000. In vitro optimal conditions for those transfer and hydrolysis reactions appeared to be pH 7.0 at $50^{\circ}C$ and pH 8.4 at $40^{\circ}C$, respectively. The denatured enzyme recovered most of its $\gamma$-GTP activity by removing detergents such as sodium dodecyl sulfate (SDS) or urea with dialysis. The enzyme showed higher affinities against a number of amino acids as $\gamma$-glutamyl acceptors than glycylglycine in the following order: L-valine, L-methionine, L-glutamic acid or L-as-paragine, L-alanine. Also, it was shown that L-glutamine was the most suitable $\gamma$-glutamyl donor for the transfer reaction among those tested. Amino acids generally inhibited the enzyme activity for the transfer reaction, but not for the hydrolysis reaction.

• Journal of Life Science
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• 제31권10호
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• pp.922-928
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• 2021

To profile the microbial compositions of Korean traditional fermented paste made from whole soybeans, Doenjang and Cheonggukjang, and compare their taxonomic differences, we analyzed the V3-V4 region of 16S rRNA of naturally fermented foods by using next generation sequencing. α-Diversity results showed that values indicating bacterial community abundances (OTUs) and richness (ACE, Chao1) were statistically significant (p=0.0001) in Doenjang and Cheonggukjang. Firmicutes was the most common phylum in both groups, representing 97.02% and 99.67% in the Doenjang and Cheonggukjang groups, respectively. Bacillus was the most dominant genus, accounting for 71.70% and 59.87% in both groups. Linear discriminant (LDA) effect size (LEfSe) analysis was performed to reveal the significant ranking of abundant taxa in different fermented foods. A size-effect threshold of 2.0 on the logarithmic LDA score was used for discriminative functional biomarkers. On the species level, Bacillus subtilis, Tetragenococcus halophilus, and Clostridium arbusti were significantly more abundant in Doenjang than in Cheonggukjang, whereas Bacillus thermoamylovorans, Enterococcus faecium, and Lactobacillus sakei were significantly more abundant in Cheonggukjang than in Doenjang. Permutational multivariate analysis of variance (PERMANOVA) showed that the statistical difference in microbial clusters between the two groups was significant at the confidence level of p=0.001. This research could be used as basic research to identify the correlation between the biochemical characteristics of Korean fermented foods and the distribution of microbial communities.

• Journal of the Korean Society of Food Science and Nutrition
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• 제40권3호
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• pp.450-457
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• 2011

Roasted soybean flour (RSF) and mixed cereals were fermented by the solid state fermentation using Bacillus subtilis HA to optimize the production of biologically active compounds. The RFS fermented with 52.7% moisture content showed higher production with protease activity of 42.6 unit/g and 10% mucilage content after fermentation for 24 hr. Tyrosine content and protease activity after 48 hr fermentation time were the highest values with 445.5 mg% and 55.1 unit/g, respectively. However, the wholesome fermented RSF (FRSF) was obtained by fermentation for 24 hr because of the production of unpleasant flavors after fermentation for 48 hr. The RSF fermented with various types and contents of cereals has no effects on tyrosine content and protease activity. However, the addition of brown rice significantly increased mucilage content, especially indicating 24.55% at the addition of 80% (w/w). For addition of barley, fibrinolytic activity was increased to 11.82 unit/g by the fortification of 60% barley. It is concluded that biologically active compounds including fibrinolytic activity and mucilage content in FRSF were dependent upon the type and content of various cereals.

• The Korea Journal of Herbology
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• 제25권4호
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• pp.7-10
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• 2010

Objectives : The purpose of this study was to investigate the nodakenin and decursin contents in each fermented Angelicae gigantis Radix by 4 species of ferment strains. Methods : The strains of fermented Angelicae gigantis Radix were Lactobacillus plantarum(SE1), L. acidophilus(AC), Bacillus subtilis(B2) and B. licheniformis(BL2). The fermentative changes of nodakenin and decursin were analyzed using HPLC. Results : All of 4 species strains reduced nodakenin and decursin concentration in Angelicae gigantis Radix by fermentation. But fermentability were difference between strains. The nodakenin concentration of AC was lower than B2. The decursin concentrations of SE1 and AC were lower than B2 and BL2. Conclusions : 4 species of fermental strain were difference decomposable rate with nodakenin and decursin in fermented Angelicae gigantis Radix.

• Korean Journal of Microbiology
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• 제47권3호
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• pp.255-262
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• 2011

Six protein-degrading bacteria were isolated from digestive organ of Harmonia axyridis. These isolates were categorized as Staphylococcus sciuri subsp. sciuri (3 strains), Bacillus subtilis (1 strain), and Bacillus thuringiensis (2 strains) by 16S rRNA gene sequence analysis. The Staphylococcus sp. CB2-3 was selected as a protease-producing bacterium which showed the highest protease activity of 58.5 U/ml at the pH 5.0 medium. The optimal pH and temperature of protease activity were pH 5.0 and $40^{\circ}C$, respectively. This acid protease had a relatively high stability of 80% between $30-50^{\circ}C$ at broad temperature range. The opimal medium compositions of carbon, nitrogen and mineral source for cell growth and protease activity were investigated. When sorbitol (0.5%) was used as carbon source, enzyme activity was increased about 2 times than that of the basal medium. When skim milk (0.5%) was used as nitrogen source, activity was increased about 2.5 times than that of the control. Cell growth and enzyme activity were increased by mineral source such as KCl, $K_2HPO_4$, $FeSO_4$, but was completely inhibited by divalent ions such as $Co^{2+}$, $Zn^{2+}$, $Mn^{2+}$, $Cu^{2+}$.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1984-1989
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• 2008

Surfactin is a natural biosurfactant derived from Bacillus subtilis and has various biological activities such as anticancer, antiplatelet, and anti-inflammatory effects. In this study, the inhibitory mechanism of surfactin in NO production from macrophages was examined. Surfactin down regulated LPS-induced NO production in RAW264.7 cells and primary macrophages with $IC_{50}$ values of 31.6 and $22.4{\mu}M$, respectively. Immunoblotting analysis showed that surfactin strongly blocked the phosphorylation of IKK and $l{\kappa}B{\alpha}$ and the nuclear translocation of $NF-{\kappa}B$ (p65). Therefore, these data suggest that surfactin may act as a bacterium-derived anti-inflammatory agent with anti-$NF-{\kappa}B$ activity.

• Korean Journal of Food Science and Technology
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• 제31권6호
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• pp.1613-1618
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• 1999

Extracts of Citrus sudachi juice and peel were obtained by several organic solvents such as hexane, acetone, ethyl acetate and methanol. Their antimicrobial spectrum were determined against 14 strains of gram positive and 4 strains of gram negative bacteria by paper disk method and minimal inhibitory concentration (MIC) was also obtained. Antimicrobial activities of solvent extracts from Citrus sudachi juice showed stronger than those of solvent extracts from peel. Acetone extract from juice showed the strongest antimicrobial activity among extracts, but the hexane extract did not show antimicrobial activities on tested target strains. The MIC was differant among tested strains; i.e. 0.5% (v/v) to Bacillus subtilis, 1% to Pseudomonas fragi, 1.5% to Listeria monocytogenes and Escherichia coli O157:H7, 2% to Propionibacterium acnes and Salmonella typhimurium, and 2.5% to Staphylococcus aureus.

• The Korean Journal of Pesticide Science
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• 제16권4호
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• pp.364-368
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• 2012

In vivo experiments were carried out to investigate the effect of microbial agents on tomato disease occurrences in a sustainable tomato farm in Gong-ju, Chung-nam during 2 years (2010-2011). Two kind of commercial microbial agents (EXTN-1 and Cillus suspension concentrate) and 2 kind of microbial agents (Bacillus subtilis strain 'B4' and 'B17') developing by National academy of agricultural science were used in this study. In the 1st experimental year, the microbial agents were sprayed on leaves for 2-4 times at 1-2 weeks interval from 3 weeks after transplanting, and then disease occurrence were observed. As a result, the control efficacies of commercial EXTN-1 and Cillus suspension concentrate (SC) against gray mold were 59.6% and 50.5% in the treatment of 4 times foliar application at 1 week interval from 3 weeks after transplanting, and the control efficacy of commercial EXTN-1 SC against gray mold was 55.4% in the treatment of 3 times foliar application at 1 week interval from 4 weeks after transplanting. However, the control efficacies of EXTN-1 and Cillus SC were not enough for tomato crop protection against powdery mildew. In the 2nd experimental year, the microbial agents were treated following by the planned combination schedule of transplanting stage drip-watering, early stage root irrigation and early blooming stage foliar application. The control efficacies of EXTN-1 SC and B17 treatment following by transplanting stage drip-watering, 2 times root irrigation at 2 weeks interval root irrigation and 4 times foliar application at 1 weeks interval for gray mold management were 57.0 and 55.1%, respectively. In the case of same treatment for gray mold management mentioned at above, the control efficacies of EXTN-1 SC, B4 and B17 treatment for powdery mildew management were 50.5, 51.3 and 52.5%, respectively.

• Korean Journal of Plant Resources
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• 제36권4호
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• pp.264-274
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• 2023

To evaluate functional biomaterials of 5 invasive alien plants, total polyphenol and flavonoid contents, antioxidant activity, anti-inflammatory activity, and antibacterial effect were measured. The total polyphenol and flavonoid contents of the extracts were in the order of Rumex acetosella L. > Hypochaeris radicata L. ≥ Lactuca scariola L. > Humulus japonicus Siebold & Zucc. ≥ Solanum viarum Dunal. The DPPH and ABTS radical scavenging activities of the extract were the highest in R. acetosella and correlated well with the total polyphenol contents. In RAW 264.7 cells stimulated with lipopolysaccharide (LPS), nitric oxide (NO) and prostaglandin E₂ (PGE₂) production inhibitory effect of the extracts (100 ㎍ SE/mL) were 20~60% and 10~70%, respectively, showing the highest inhibitory effect in R. acetocella. The extracts of R. acetosella, H. japonicus and S. viarum showed antibacterial activity against food poisoning-causing microorganisms such as Bacillus subtilis, Escherichia coli, Vibrio parahaemolyticus and Vibrio vulnificus. Furthermore, the H. japonicus extract was found to have effective antibacterial activity against oral microorganisms such as Enterococcus faecalis, Lacticaseibacillus casei, Rothia dentocariosa, Staphylococcus epidermidis and Streptococcus mutans, and its major active ingredients were predicted to be pentadecylic acid, palmitic acid and clionasterol. These results suggest that alien plants have potential as biomaterials with antioxidant, anti-inflammation and antibacterial effects.