• The Korean Journal of Food And Nutrition
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• v.8 no.1
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• pp.1-5
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• 1995

ATPase was the most available phosphatase in culture broth of 5. coli P90C. To measure the stable phosphatase activity it was necessary to react nth reaction reagent over 30 min and then we can get stable optical density at 410 m. Transfer time from preculture to main culture for the production of $\beta$-glactosidase was good after 3 hrs cultivation. Phosphatase activity was highest at log phase in main culture and as the cell begins to make $\beta$-galactosidase phosphatase activity begins to decrease.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.169-172
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• 2012

The aim of this research was to investigate the antibacterial activity of Clerodendron trichotomum. Antibacterial activities of the n-hexane, methylene chloride (MC), ethyl acetate, and n-butanol fractions from C. trichotomum were tested against Staphylococcus aureus, Escherichia coli, and Helicobacter pylori. The n-hexane and MC fractions showed antibacterial activity against H. pylori at a concentration of 1.7 mg/mL and showed inhibition zones of 10 and 11 mm in disc assay, respectively. Further testing of 22-dehydroclerosterol and ${\beta}$-amyrin (each 3.4 mg/mL) from the MC fraction of C. trichotomum revealed moderate antibacterial effects against E. coli, S. aureus, and H. pylori. In particular, ${\beta}$-amyrin showed clear zones of 12 and 13 mm against E. coli and H. pylori, respectively, suggesting its potential as an antibacterial agent. The active compounds from C. trichotomum might provide a promising therapeutic agent against infections by E. coli, S. aureus, and H. pylori.

• BMB Reports
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• v.39 no.1
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• pp.16-21
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• 2006

The coat protein (CP) of Papaya ringspot virus (PRSV) was analyzed for presentation of the antigenic peptide of animal virus, Canine parvovirus (CPV), in Escherichia coli (E. coli). The 45 nucleotides fragment coding for the 15-aa peptide epitope of the CPV-VP2 protein was either inserted into the PRSV-cp gene at the 5', 3' ends, both 5' and 3' ends or substituted into the 3' end of the PRSV cp gene. Each of the chimeric PRSV cp genes was cloned into the pRSET B vector under the control of the T7 promoter and transformed into E. coli. The recombinant coat proteins expressed from different chimeric PRSV-cp genes were purified and intraperitoneally injected into mice. All of the recombinant coat proteins showed strong immunogenicity and stimulate mice immune response. The recombinant coat proteins containing the CPV epitope insertion at the C terminus and at both N and C termini elicited ten times higher specific antisera in immunized mice compared with the other two recombinant coat proteins which contain the CPV epitope insertion at the N terminus and substitution at the C terminus.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.574-579
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• 1989

Chromosomal DNA fragments of Bacillus sp. YA-14, isolated from soil as a potent $\beta$-xylosidase producing bacterium, were ligated to a vector plasmid pBR322 and used to transfer Escherichia coli HB101 cells. The recombinant plasmid pYXL22 was found to enable the transformants to produce $\beta$-xylosidase. pYXL22 was found to contain the 7.0 kb HindIII DNA fragment originated from the Bacillus sp. YA-14 chromosomal DNA by Southern hybridization. The optimum temperature for the reaction of $\beta$-xylosidase produced by E. coli HB101 (pYXL22) was appeared at 3$0^{\circ}C$. The enzyme was maintained stably up to 4$0^{\circ}C$ when stored 1hr at 4$0^{\circ}C$. The $\beta$-xylosidase was repressed completely by 0.4% (w/v) glucose concentration in E. coli HB101 (pYXL22). The optimum concentration of xylose for the $\beta$-xylosidase production in Bacillus sp. YA-14 was 0.2% (w/v).

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.39-46
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• 1995

This study was carried out to investigate antibacterial activities of the green tea extract according to storage temperature as death velocity constant. The survey data were collected from seven green teas (2 Korean, 2 Japanese, 2 Chinease and 1 Vietnamese) and experimental strains were used E. coli No. 11234, Ent. aerogenes No. 11783, Ps. fiu. orescens No. 11210, S. marscens No. 11808, St. mutans No. 11823 and V. parahaernolyticus No. 11965. The experimental results obtained were as follows: 1. Antibacterial activities of the green tea extracts according to the strains were strikingly difference. That is, those of the samples appeared to be conspicuous on [St. mutans No. 11823 (Range of death velocity constant a day after, at 20$\circ$C 4.85~5.22) and V. parahaemolyticus No. 11965 (4.70~6.00) while E. coli No. 11234 (0.59~-0.30) and Ent. aerogenes No. 11783 (0.24~-0.11)] were not so. 2. To storage temperature at 5$\circ$C than that at 20$\circ$C, antibacterial activities of the green tea extract on Ps. fluorescens No. 11210, S. marscens No. 11808, E. coli No. 11234, and Ent. aerogenes No. 11783 were sensitived but St. mutans No. 11823 and V. parahaemolyticus No. 11965 were not related to those. 3. Antibacterial activities to the strains were increased within two days.

• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.155-159
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• 1982

A polyvalent live Escherochia coli oral vaccine were prepared by the use of 5 field isolates of enteropathogenic E. coli, serotypes 08 : K87, K88a, b ; 0138 : K81, K88a, c ; 0141 : K85a, b, K88a, b ; 0149 : K91, K88a, c and 0157 : K'V17', K88a, c. Some field experiments were conducted to investigate the effectiveness of the polyvalent live E. coli oral vaccine in the prevention of neonatal colibacillosis in piglets suckling orally vaccinated sows. Seventy-nine pregnant sows in an intensive pig farm were vaccinated with oral vaccine 4 weeks prior to farrowing and 19 sows were chosen for control. The piglets suckling vaccinated sows showed a significant protection against neonatal enteric colibacillosis during the 2 weeks observation period from the farrowing but no significant differences in protection between vaccinated and control group were observed with piglets older than 15 days.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.107-110
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• 2007

The putative laccase gene, yacK of Escherichia coli, K-12 is not expressed in lab culture conditions. The laccase gene was amplified by PCR and subcloned into pET28a vector. The laccase overproduced in E. coli harboring pET28a was purified by His-affinity column chromatography. The purified laccase, which has the apparent molecular weight of 55,000 on the SDS-polyacrylamide gel showed enzyme activity on the guaiacol solution and agar plate. Optimum temperature and pH were around 65$^{\circ}C$ and 5.0, respectively.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.83-87
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• 2021

Antimicrobial activity of an aqueous extract from Caesalpinia sappan L. was investigated against skin flora such as Escherichia coli, Staphylococcus aureus, Cutibacterium acnes, and Malassezia furfur. The yield and polyphenol content of the aqueous extract were 14.01±0.81% and 487.5±19.69 ㎍/mg-extract, respectively. The minimum inhibitory concentration of the aqueous extract against E. coli, S. aureus, C. acnes, and M. furfur was 0.875, 1.750, 1.750, and 1.750 mg/mL, respectively. In disc diffusion test, the aqueous extract of C. sappan L. increased the clear zone in a dose-dependent manner. The aqueous extract inhibited the microbial growth in a concentration-dependent manner.

• Korean Journal of Microbiology
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• v.23 no.2
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• pp.107-114
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• 1985

In order to use for recipient strains of RP4:Mu cts, 5 strainsof Rhizobium were selected among 32 strains, which were isolated and identified in this study. Hybrid plasmin RP4::Mu cts, which, is temperature sensitive and confers resistance to ampicillin, kanamycin and tetracycline was transfered by conjugation from E. coli to other atrains of C. coli and the symbiotic nitrogen fixer, Rhizobium leguminosarum. Transfer frequencies of RP4::Mu cts plasmid from E. coli to Rhizobium were about $10^{-8}-10^{-7}$ in LB agar and YMA media. The transconjugants were confirmed by demonstrating that the drug-resistant and temperature-sensitive clones isolated were drug-resistant and temperature-sensitive clones isolated were capable of releasing phage and forming plaques. The plaque-forming units of transconjugants were about $10^2\;to\;10^3$. Stability test of RP4::Mucts in Rhizobium represented that most of the transconjugants had drug resistance and produce phage Mu cts.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.835-839
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• 2011

The characteristics of torch-type atmospheric pressure plasma and its sterilization effects have been analyzed. The length of plasma flame was varied with the level of applied voltage and the mixture gases composed of argon and oxygen. The effect of plasma flame on the temperature increase of surface treated was limited to $43^{\circ}C$ as a maximum temperature under exposing time of 10 min. The sterilization for E. coli was strongly affected by the applied voltage, the oxygen ratio in the mixture gas and the treatment time. At a high concentration of ozone, the increase of treatment time under the direct contact with plasma flame yields to maximize the effect of the sterilization on E. coli.