• Korean journal of applied entomology
• /
• v.35 no.1
• /
• pp.85-90
• /
• 1996

Bacillus thuringiensis NT0423 produces quite a typical bipyramidal crystals of a common major band of ca. 130 kDa, and has dual specificity against Lepidoptera and Diptera. To enforce the Diptera-toxicity of B. thuringiensis NT0423, cryND gene was transformed 30 B. thuringiensis NT0423. The transfonnant B. thuringiensis PT1227 was obtained from introduction of pCGl0 into B. thuringiensis NT0423 by electroporation. The result showed that cryND and resident crystal protein genes in transformant were stably expressed with its own shape. Furthermore, the toxicity of B. thuringiensis PT1227 against Diptera was highly enforced, suggesting that the enforced toxicity of B. thuringiensis PT1227 was due to synergistic effect of both introduced and resident crystal proteins in transformant.

• KSBB Journal
• /
• v.8 no.1
• /
• pp.62-68
• /
• 1993

Transformed rice plantlet were recovered from protoplasts by electroporation with the plasmld pB 1121, which contain the plant expressible NPT-II and GUS genes. Embryonic cell suspension culture was established with embryonic callus induced from mature seeds of rice (Oryza sativa L. cv. Dong-jin) on the MS medium supplemented with 2.0 mg/l 2,4-D, 0.5 mg/l kinetin, 3% sucrose. Protoplasts isolated from embryonic cell suspensions were electroplated and then poterltialty-transformed tissues were selected by growth on the medium containing 200 mg/l kanamycin sulfate. When subjected to GUS assay, they stained blue, indicating the expression of the inserted GUS genes. Plantlets were regenerated from electroplated protoplasts on the hormone free MS medium. Transferred foreign genes in the plants were confirmed by southern hybridization. These results support use of electroporation for transformation of these important cereal plants.

• Journal of Microbiology
• /
• v.45 no.3
• /
• pp.241-245
• /
• 2007

This study was conducted to determine the optimal conditions for introduction of exogenous DNA into Synechocystis sp. PCC 6803. Of the three transformation techniques studied, electroporation, ultrasonic transformation and natural transformation, natural transformation showed the highest efficiency. Additionally, this study demonstrated that the higher plasmid concentration and longer homologous recombining fragments resulted in a greater number of transformants. For successful transformation, the lowest concentration of plasmid was $0.02\;{\mu}g/ml$, and the shortest homologous recombining fragment was 0.2 kb. Use of Synechocystis sp. PCC 6803 in the logarithmic growth phase resulted in two-fold higher transformation rate than that of the same organism when cells in the latent phase or the plateau phase were used for transformation. Pretreatment of the host strain, Synechocystis sp. PCC 6803, with EDTA (2 mM) for two days prior to transformation increased the transformation efficiency by 23%. Additionally, incubation of the cells and DNA for 5 h under light conditions increased the transformation efficiency by two orders of magnitude. Moreover, recovery treatment of the cells before they were plated onto antibiotic medium also increased the transformation efficiency.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.5
• /
• pp.774-783
• /
• 2007

In the present study, acidocin 1B, a bacteriocin produced by Lactobacillus acidophilus GP 1B, exhibited profound inhibitory activity against a variety of LAB and pathogens, including Gram-negative bacteria, and its mode of action was to destabilize the cell wall, thereby resulting in bactericidal lysis. Acidocin 1B was found to be heat stable, because it lost no activity when it was heated up to $95^{\circ}C$ for 60 min. It retained approximately 67% of the initial activity after storage for 30 days at $4^{\circ}C$, and 50% of its initial activity after 30 days at $25^{\circ}C$ and $37^{\circ}C$. The molecular mass of acidocin 1B was estimated to be 4,214.65 Da by mass spectrometry. Plasmid curing results indicated that a plasmid, designated as pLA1B, seemed to be responsible for both acidocin 1B production and host immunity, and that the pLA1B could be transformed into competent cells of L. acidophilus ATCC 43121 by electroporation. Our findings indicate that the acidocin 1B and its producer strain may have potential value as a biopreservative in food systems.

• KSBB Journal
• /
• v.10 no.1
• /
• pp.23-29
• /
• 1995

Calli were induced from leaf base region of germinated rice(Oryza sativa L. cv. Nakdong) with high frequency of up to 65% on LS medium supplemented with $2.5mg/{\ell}2$, 4-D in the dark at $27^{\circ}C$. Embryogenic calli of pale yellow, globular type were selected and used for the initiation of cell suspension cultures in AA2 liquid medium with $2mg/\ell$ 2,4-D, 0.2mg/$\ell$ kinetin arid $0.1mg/\ell$ GA3. Protoplasts were isolated from the embryogenic cell suspensions after 4 months of culture and then were electroporated with 400V/cm for 1 msec. Electroporated protoplasts divided with plating efficiency of 1.1% on PCM liquid medium supplemented with $2.5mg/\ell$ 2, 4-D, $0.1mg/\ell$ kinetin and 10mM proline. The protoplasts-derived microcalli were cultured on $0.2{\mu}m$ membrane fitter placed onto LS2.5 solid medium containing fine suspension cells as a feeder cells, for 2 weeks in the dark at $27^{\circ}C$. After an additional 2 weeks of culture under fluorescent light of $30{\pm}/3{\mu}E$.m^{-2}S^{-1}, yellow calli of 2mm diameter were transferred to regeneration medium. Shoots were produced from the green spot of protoplasts-derived calli and plants were regenerated form protoplast-derived green calli with frequencies of 11∼33%.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.23-30
• /
• 1998

The cryIB, truncated cryIB$[cryIB({\alpha})]$, cryIA(b), and cytA genes, encoding 135-, 89-, 131-, and 27-kDa proteins, respectively, from Bacillus thuringiensis were cloned into a shuttle vector pBES and expressed in E. coli and Bacillus species. The morphology and solubility in alkaline buffer of the insecticidal crystal proteins were investigated. Transformation of intact cells of E. coli and Bacillus species was achieved by electroporation. High field strength of 11.0 kV/cm and resistance of 129 ohms were required for efficient transformation of E. coli strains and 4.5 kV/cm and 48 ohms for Bacillus species. Strains of recombinant E. coli and Bacillus species produced the insecticidal crystal proteins and accumulated as the same bipyramidal and irregular structures as those of CryIB and IA(b) and CytA of B. thuringiensls, respectively. The insecticidal crystal proteins accumulated in recombinant E. coli wire smaller in size than those in recombinant Bacillus species. The solubility in alkaline buffer of the insecticidal crystal proteins of recombinant E. coli increased gradually as the pH increased, whereas in the case of Bacillus species the solubility increased gradually as the pH increased up to 9 and then the solubility increased greatly up to two times higher than that of E. coli proteins.

• KSBB Journal
• /
• v.24 no.2
• /
• pp.182-188
• /
• 2009

Lactobacillus spp., primary members of probiotics, have significant benefits for health and well-being of human. In this study Lactobacillus strains representing six species (L. paracasei KLB58, L. fermentum MS79 and KLB282, L. plantarum KLB213, L. gasseri KLB238, and L. reuteri KLB270) isolated from Korean adults were electrotransformed with plasmid pNCKH104. To determine optimal electrotransformation conditions, various conditions including cell wall weakening agent, electroporation buffer, electric field strength and time constant were tested for each strain. Overall, high transformation efficiency of approximately 2.5 ${\times}$ $10^3$ ${\sim}$ 5.5 ${\times}$ $10^4$ CFU/${\mu}g$ DNA was obtained where conditions of 0.5 M sucrose electroporation buffer, 1.8 kV pulse voltage and 5 ms time constant were applied. The common conditions developed in this study will make transformation of various Lactobacillus spp. easier than previous procedures.

• Proceedings of the KSAR Conference
• /
• 2002.06a
• /
• pp.34-34
• /
• 2002

핵이식 방법은 형질전환 동물을 생산하기 위한 여러 가지 방법 중 최근에 많이 이용되고 있다. 본 실험은 형광단백질 유전자 (green fluorescence protein, GFP)가 도입된 태아섬유아세포를 이용 핵이식을 하여 형질전환 수정란의 생산효율을 검토하기 위하여 실시하였다. GFP 유전자는 임신 45-55 일령의 태아섬유아세포 (KbFF3)에 electroporation방법으로 transfection을 실시하였다. (중략)

• Bulletin of Food Technology
• /
• v.7 no.2
• /
• pp.13-15
• /
• 1994

유산균은 발효유, 치즈, 발효 sausage 및 채소의 생산에 널리 이용되고 있다. 과거 15~6년간 이들 유산균에 대한 경제적 중요성은 매우 증가하였으며 이에 따라 유산균의 유전학과 plasmidbiology를 이해함으로써 이들 균에 대한 분자 생물학적 육종에 대한 많은 연구가 진행되어 왔다. 유산균에서 잘 기능을 하는 cloning vector들이 많이 개발되었으며 transduction, conjugation, transformation, electroporation 등의 외부 유전자를 전달하는 방법으로 보다 개발된 유산균이 육종되어 왔다. 이 총설은 산업적으로 유용가치가 높은 유산균의 육종에 관한 최신동향 및 앞으로의 전망 등에 관하여 논의하고자 한다.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.48-48
• /
• 2003

Electric field induces cell fusion, electroporation on biological cells, including apoptosis. Apoptosis is expressed in a series of natural enzymatic reactions for the natural elimination of unhealthy, genetically damaged, or otherwise aberrant cels that are not needed or not advantageous to the well-being of the organism. Its markers involve cell shringkage, activation of intracellular caspase proteases, externalization of phosphatidylserine at the plasma membrane, and fragmentation of DNA.