• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.191-196
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• 1996

The bacteriolytic enzyme produced from Bacillus subtilis SH-1 was purified and characterized, and its molecular weight was determined. The bacteriolytic enzyme activity was increased about 66.5 times via purification with recovery yield of 18.5%. The optimum pH and temperature of this enzyme were 9.0 and 50$\circ$C. The enzyme was stable within a pH range of 6.0-10.0 and unstable above 60 . The molecular weight of the enzyme was estimated to be 23,000 dalton in a form of monomer with no other subunits. Effect of the enzyme on the lysis of bacteria engaged in food posion was tested. The lysis degree was below 31% against Gram negative bacteria and above 48% in Gram positive bacteria. The values higher than 73% were obtained against Vibrio sp. and Listeria sp. As the turbidity of dissolved peptidoglycan clecreases, the free amino group levels were increased. And, based on hydrolysis of casein, this enzyme was thought to be an endopeptidase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.150-165
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• 2002

The purpose of this study was to evaluate bacteriocin activity against human flora. Lactobiocin, a bacteriocin produced by Lactococcus sp. HY 449, inhibited the growth of Starphylococcus epidermidis, Starphylococcus aureus, Streptoccoccus pyogenes and Propionibacterium acnes. When crude bacteriocin was added to indicator cells during logarithmic growth, the optical density(O.D 650nm) of cells without bacteriocin increase after 5h of incubation. Whereas in the presence of bacteriocin, the O.D of cell suspensions decreased. The similar patterns were observed for absorbance readings at 280 nm and 260 nm. The release of cellular components when cell were treated with Lactobiocin suggests some degree of membrane damage or cell lysis. Scanning electron microscopy of cells following treatments with Lactobiocin in PBS buffer revealed disruptures of cell morphology. These results indicate that bacteriocin appears to cause cell lysis of tested strains. In cytotoxicity on human fibroblast, LD$\_$50/ of Lactobiocin was ca. 50 mg/ml and no change was observed cell proliferation at the same concentration. Any irritation and allergic reaction did not observed when evaluated by human patch test for Lactobiocin.

• Proceedings of the Korean Society of Toxicology Conference
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• 1998.10a
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• pp.48-48
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• 1998

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.149-153
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• 2005

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.172-178
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• 1997

Xanthmonas campestris pv. campestris, causal agent of Black rot of crucifers, were isolated and identified from crucifer host. In order to determine the characters of X. c. pv. campestris associated with pathogenicity, Tn5 mutagenesis was carried out by conjugating with E. coli pJB4J1. Transconjugants were plate- assayed for missing cellulase, protease and amylase activity. A cellulase negative mutant was selected and tested for pathogenicity. Light microscopy and Scanning electron microscopy revealed that substomatal tissues were colonized by mutant, but was far less extensive than those by wild type. Stomatal surface and substomatal tissue appeared to have degraded by only wild type in 24 hrs and progression of pathogenesis was distinct in 48 hrs. In 6 days, wild type proliferated well in the tissue facilitated by cellulase activity. As a result, cellulase was determined as the important factor in pathogenesis.

• The Journal of Internal Korean Medicine
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• v.18 no.1
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• pp.97-113
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• 1997

The present experiment was designed to investigate the effects of Sambutang water extracts on the serum cholesterol levels and the cardiovascular system in the experimental animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurment of Mortality rate was observed for measuring the effect of Sambutang water extract. Sambutang water extract against pulmonary thromboembolism induced by collagen the mixture(0.1 ml/10 g, 2 mg/kg) plus serotonin(5 mg/kg) in mouse. The effect of Sambutang water extract was examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as follows. 1. Sambutang decreased the serum cholesterol levels in rats. 2. Sambutang dropped the blood pressure in spontaneous hypertensive rat. 3. The drug increased the auricular blood flow in rabbit. 4. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 5. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 6. The drug inhibited the platelet aggregation in rat. 7. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 8. The drug increased the antithrombin activity in rat and the fibrinogen lysis time was reduced and lysis area was increased. 9. Sambutang reduced fibrinogen lysis time of rat in vitro assay. According to the above mentioned results. Sambutang increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug presented the antithrombin activity, inhibited the platelet aggregation.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1162-1168
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• 2007

Although widely used as a host for recombinant protein production, Escherichia coli is unsuitable for massive screening of recombinant clones, owing to its poor secretion of proteins. A vector system containing T4 holin and T7 lysozyme genes under the control of the ptsG promoter derivative that is inducible in the absence of glucose was developed for programmed cell lysis of E. coli. Because E. coli harboring the vector grows well in the presence of glucose, but is lysed upon glucose exhaustion, the activity of the foreign gene expressed in E. coli can be monitored easily without an additional step for cell disruption after the foreign gene is expressed sufficiently with an appropriate concentration of glucose. The effectiveness of the vector was demonstrated by efficient screening of the amylase gene from a Bacillus subtilis genomic library. This vector system is expected to provide a more efficient and economic screening of bioactive products from DNA libraries in large quantities.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.7-11
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• 2006

To see effect of marine rock powder and fungal culture supernatant, we analyzed the biodegradation rates of harmful marine dinoflagellate, Heterosigma akashiwo and Prorocentrum minimum for developing the effective control methodology of algal bloom. Relatively low removal rates were observed in the treatment of marine rock powder or buffer solution alone. However, the lysis of H. akashiwo and P. minimum was enhanced in the combined treatments of marine rock powder with fungal supernatant. The effective concentration and exposure time of fungal supernatant for the lysis of H. akashiwo and P. minimum were 5 ml/l and 30 minutes, respectively. These results suggest that the fungal supernatant may be a biocontrol agent for the control of algal blooms in seawater.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.889-893
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• 2005

Cell lysis method is very important to study intracellular metabolites in microorganisms. In this study, various cell lysis methods were compared to find a good method analysing intracellular metabolites in P. pastoris. P. pastoris was cultivated in YPD medium at 30 $^{\circ}C$, 200 rpm for 24 hours and its morphology as well as the change in strain's shape were observed by microscopy. The UV/vis spectrophotometer was used to measure intracellular protein concentrations.

• Journal of Korean Biological Nursing Science
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• v.4 no.2
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• pp.69-77
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• 2002

The purpose of this study was to identify the relationship of symptom distress and natural killer cell cytotoxicity in breast cancer patients who had been radiation therapy and/or chemotherapy after surgery. Symptom distress measured by modified Lee's(1994) physical symptom questionnaire. For measuring the natural killer cell cytotoxic activity. 8ml to 10ml blood was collected from the subjects. Mononuclear cell was isolated by centrifuge of the blood and cultured by putting $Cr^{51}$, and reacted with target cell, K562 cell. Amount of $Cr^{51}$ was measured, and %lysis was calculated. The results were as follows. 1) Symptom distress score was 42.18, which is moderate symptom distress. 2) Natural killer cell cytotoxic activities were 42.18%lysis(effector : target cell ratio=100 : 1) and 28.05%lysis(effector : target cell ratio=50 : 1). 3) Correlation coefficients of symptom distress and natural killer cell cytotoxic activity were $-.134{\sim}-.461$. Though significant correlation was not found between total score of symptom distress and natural killer cell cytotoxic activity, 3('pain' 'feel hot on radiation site' and 'difficulty in breathing') of 19 symptom distress items and natural killer cell cytotoxic activity showed significant negative correlation(p<.05). These findings suggest that 1) breast cancer patients who had been radiation therapy and/or chemotherapy after surgery have moderate symptom distress and decreased natural killer cell cytotoxic activity. 2) The symptom distress was not related to natural killer cell cytotoxic activity.