• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.974-983
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• 2013

Bacillus amyloliquefaciens CB1 was isolated from cheonggukjang, a Korean fermented soy food. B. amyloliquefaciens CB1 secretes proteases with fibrinolytic activities. A gene homologous to aprE of Bacillus subtilis, aprECB1, was cloned from B. amyloliquefaciens CB1, and DNA sequencing showed that aprECB1 can encode a prepro-type serine protease consisting of 382 amino acids. When aprECB1 was introduced into B. subtilis WB600 using an E. coli-Bacillus shuttle vector, pHY300PLK, transformants showed fibrinolytic activity and produced a 28 kDa protein, the size expected for the mature enzyme. The 28 kDa fibrinolytic enzyme was purified from the culture supernatant of B. subtilis WB600 transformant. AprECB1 was completely inhibited by phenylmethylsulfonyl fluoride and almost completely inhibited by EDTA and EGTA, indicating that it is a serine metalloprotease. AprECB1 exhibited the highest specificity for N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, a known substrate for ${\alpha}$-chymotrypsin. $A{\alpha}$ and $B{\beta}$ chains of fibrinogen were quickly degraded by AprECB1, but the ${\gamma}$-chain was resistant.

• KSBB Journal
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• v.28 no.1
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• pp.18-23
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• 2013

The purpose of this work was to investigate the several functional characteristics of Lactobacillus sakei JK-17 isolated from long-term fermented kimchi, Muk Eun Ji. Initially, phylogenetic analysis using 16S rRNA sequencing was performed to identify the isolate JK-17, and the strain could be assigned to Lactobacillus sakei and designated as L. sakei JK-17. The strain was registered in GenBank as [JX841311]. The changes of bacterial growth and residual organic acids were monitored and HPLC was used to measure quantitatively two organic acids, lactic acid and acetic acid, produced in the culture during 84 hours of incubation. During the incubation period, several functional characteristics of L. sakei JK-17 were examined. L. sakei JK-17 culture depleted nitrite concentration 94.75%. Antioxidant activity of cultural supernatants of L. sakei JK-17 was approx. 53.8%, and ${\beta}$-galactosidase activities were 0.243 units/mL at pH 7.0 and 0.387 units/mL at pH 4.1, respectively. The antibacterial activities against food-poisoning causing bacteria were examined with 20-fold concentrated culture supernatants from L. sakei JK-17 and the antibacterial effects were clearly observed against all bacteria tested in this work.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.339-347
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• 2017

Sclerotium rolfsii causing southern blight on numerous vegetable and fruit crops was isolated from stems of chili peppers showing wilting symptoms. The pathogen was identified by morphological observation and DNA sequencing analysis of ITS region. To select an effective fungicide for control of southern blight, we investigated the inhibition efficacy of thirty fungicides included in nine groups of fungicides with different mechanisms of action. A fungal growth inhibition assay was conducted through an agar dilution method by using mycelial discs and sclerotia of the pathogen as inoculum, respectively. When mycelial discs were used as an inoculum, several fungicides showed good inhibitory activity against the mycelial growth of S. rolfsii 12-6. All DMI fungicides tested had a good inhibition except for prochloraz which had low inhibitory effect. All strobilurin fungicides tested except for kresoxim-methyl and all SDHI fungicides tested except for boscalid and fluopyram, had a good inhibition. Also, fludioxonil, a protective fungicide and fluazinam had a good inhibitory effect. Interestingly, when sclerotia were used as an inoculum, inhibition efficacy was increased for fluopyram, a SDHI fungicide, and for some protective fungicides such as propineb, chlorothalonil, dithianon, and folpet. All the fungicides selected in this study should be tested in the field for their control activities against stem rot for practical use in chili pepper cultivation.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.133-137
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• 2007

The Strain TFM-7, Which has an antitumor effect, was isolated from Kefir and identified based on analysis using the API 50 CHL kit and 265 rDNA sequencing. Strain TFM-7 was confirmed to belong to the genus Kluyveromyces. Analysis of the 265 rDNA nucleotide sequences found strain TFM-7 to be related to Kluyveromyces marxianus. NRRL Y-828IT. K. marxianus. TFM-7 was cultured with potato dektrose broth medium at $27^{\circ}C$ for 72 hr, and its inhibition effects on the proliferation of seven tumor cell lines and a normal cell line were assessed using the MTT assay. The antitumor effects and growth characteristics of K. marxianus TFM-7 were investigated during a culture period of 7 days. By the $3^{rd}\;day$, K. marxianus TFM-7 showed a dry cell weight 2.39 g/L, a pH of 4.39, an ethanol content of 0.89%, and an inhibition effect on the proliferation of seven tumor cell lines above 50%, except for A-549 tumor cell line. K. marxianus TFM-7 was the most effective at inhibiting the growth of Hep-2 cell line among all tumor cell lines tested. Growth inhibition of a normal cell line, NIH/3T3, was less than 35%, suggesting a decreased level of cytotoxicity toward normal cells. These results indicate that K. marxianus TFM-7 may have used as a yeast strain with antitumor activity.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.301-305
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• 1994

In catalytic properties of the restriction enonuclease, SdiI, which was purified from Streptomyces diastatochromogenes, this enzyme was active at wide range between pH 7.0 and 12.5, and up to $60^{\circ}C$ and 500 mM of NaCl concentration. It was stable between 20^{\circ}C$ and $60^{\circ}C$, and essentially requires $MgCl_2$ for endonuclease activity. The restriction map of lambda DNA which was obtained by double digestion with various enzymes suggested SdiI to be an isoschizomer of XhoI. From the determination of restriction site based on DNA sequencing method, recognition and cleavage specificity of SdiI was concluded as: 5‘-C${\downarrow}$TCGA G-3' 3'-G AGCT${\uparrow}$C-5'

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.340-348
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• 2005

Laboratory scale experiments were conducted to compare the performance of two types of sequencing batch reactor(SBR) systems, anoxic-oxic-anoxic-oxic $((AO)_2)$ SBR and anoxic-oxic-anoxic $(A_2O)$ SBR on the biological nitrogen and phosphorus removal. Also, the profiles of DO and pH in reactors were used to monitor the biological nutrient removal in two SBRs. The break point in the pH and DO curves at the oxic period coincided with the end of nitrifying activity at about 1 h 30 min in oxic phase, and the change in pH appears to be related to nitrate concentration. The TOC removal efficiency in $A_2O$ SBR was higher than that in $(AO)_2$ SBR. The denitrification was completed at the influent period. The 2nd non-aeration and aeration periods were not necessary for the nitrogen and phosphorus removal because of the low influent TOC concentration in this study. The release and uptake of phosphorus in $AO_2$ SBR was much higher than that in $(AO)_2SBR.$ In order to uptake more phosphorus, the 1st aeration period in $A_2O$ SBR should be prolonged.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.822-829
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• 2007

A gene coding for phosphoketolase, a key enzyme of carbohydrate catabolism in heterofermentative lactic acid bacteria(LAB), was cloned from a Lactobacillus paraplantarum C7 and expressed in Escherichia coli. The gene is 2,502 bp long and codes for a 788-amino-acids polypeptide with a molecular mass of 88.7 kDa. A Shine-Dalgarno sequence(aaggag) and an inverted-repeat terminator sequence are located upstream and downstream of the phosphoketolase gene, respectively. The gene exhibits an identity of >52% with phosphoketolases of other LAB. The phosphoketolase of Lb. paraplantarum C7(LBPK) contains several highly conserved phosphoketolase signature regions and typical thiamine pyrophosphate(TPP) binding sites, as reported for other TPP-dependent enzymes. The phosphoketolase gene was fused to a glutathione S-transferase(GST::LBPK) gene for purification. The GST::LBPK fusion protein was detected in the soluble fraction of a recombinant Escherichia coli BL21. The GST::LBPK fusion protein was purified with a yield of 4.32mg/400ml by GSTrap HP affinity column chromatography and analyzed by N-terminal sequencing. LBPK was obtained by factor Xa treatment of fusion protein and the final yield was 3.78mg/400ml. LBPK was examined for its N-terminal sequence and phosphoketolase activity. The $K_M\;and\;V_{max}$ values for fructose-6-phosphate were $5.08{\pm}0.057mM(mean{\pm}SD)$ and $499.21{\pm}4.33{\mu}mol/min/mg$, respectively, and the optimum temperature and pH for the production of acetyl phosphate were $45^{\circ}C$ and 7.0, respectively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.4
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• pp.263-267
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• 2017

Patients with lysosomal acid lipase (LAL) deficiency and glycogen storage disease (GSD) demonstrated hepatomegaly and dyslipidemia. In our case, a 6-year-old boy presented with hepatosplenomegaly. At 3 years of age, GSD had been diagnosed by liver biopsy at another hospital. He showed elevated serum liver enzymes and dyslipidemia. Liver biopsy revealed diffuse microvesicular fatty changes in hepatocytes, septal fibrosis and foamy macrophages. Ultrastructural examination demonstrated numerous lysosomes that contained lipid material and intracytoplasmic cholesterol clefts. A dried blood spot test revealed markedly decreased activity of LAL. LIPA gene sequencing identified the presence of a novel homozygous mutation (p.Thr177Ile). The patient's elevated liver enzymes and dyslipidemia improved with enzyme replacement therapy. This is the first report of a Korean child with LAL deficiency, and our findings suggest that this condition should be considered in the differential diagnosis of children with hepatosplenomegaly and dyslipidemia.

• Korean Journal of Microbiology
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• v.55 no.2
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• pp.157-159
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• 2019

Pseudomonas fluorescens NBC275 (Pf275) isolated from soil sample collected at riverside of Nakdonggang showed antagonistic activity against fungal pathogens of plants and insects. Here we present complete genome sequence of Pf275. The genome comprises of 6,610,362 bp with GC content of 60.9%, which includes 5,869 predicted protein-coding genes, 16 rRNAs, and 65 tRNAs. Genome analysis revealed gene clusters encoding antimicrobial secondary metabolites such as pyoverdine, 2, 4-diacetylphloroglucinol, and phenazine, which are known to play essential roles in biocontrol of diseases.

• BMB Reports
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• v.52 no.2
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• pp.133-138
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• 2019

Upon viral infection, the 2', 5'-oligoadenylate synthetase (OAS)-ribonuclease L (RNaseL) system works to cleave viral RNA, thereby blocking viral replication. However, it is unclear whether OAS proteins have a role in regulating gene expression. Here, we show that OAS1 and OAS3 act as negative regulators of the expression of chemokines and interferon-responsive genes in human macrophages. Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (Cas9) technology was used to engineer human myeloid cell lines in which the OAS1 or OAS3 gene was deleted. Neither OAS1 nor OAS3 was exclusively responsible for the degradation of rRNA in macrophages stimulated with poly(I:C), a synthetic surrogate for viral double-stranded (ds)RNA. An mRNA sequencing analysis revealed that genes related to type I interferon signaling and chemokine activity were increased in $OAS1^{-/-}$ and $OAS3^{-/-}$ macrophages treated with intracellular poly(I:C). Indeed, retinoic-acid-inducible gene (RIG)-I- and interferon-induced helicase C domain-containing protein (IFIH1 or MDA5)-mediated induction of chemokines and interferon-stimulated genes was regulated by OAS3, but Toll-like receptor 3 (TLR3)- and TLR4-mediated induction of those genes was modulated by OAS1 in macrophages. However, stimulation of these cells with type I interferons had no effect on OAS1- or OAS3-mediated chemokine secretion. These data suggest that OAS1 and OAS3 negatively regulate the expression of chemokines and interferon-responsive genes in human macrophages.