• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.23-28
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• 1994

This study was rimed out to examine the difference in the cell vitality between mesophyII protoplast (MP) and paraveinal mesophyII protoplast (PVMP) of Nicotiana tabaccum 'Xanti', Petunia hybrida 'Blue Star' and Chrysanthemum morifolium 'Baeckwang' by using urea permeability technique. The effects of various enzyme solutions and incubation time, NAA and thidiazron on plant regeneration from isolated protoplasts were also investigated. The vibratome technique was used for protoplast isolation and urea permeability test because the fresh living, thin tissue stripes (50 ${\mu}{\textrm}{m}$ of thickness) could be obtained with minimal damage with the vibratome. For the three plants examined, the urea permeability on the tested tissue stripes was relatively higher in PVMP than in MP by about Ks = 2.0 $\times$ 10$^{-5}$ cm/sec. The treatment of an enzyme mixture of 1.5% cellulase R-10, 1% Driselase, 0.5% Macerozyme R-10, and 0.5% Pectinase for 4 to 8 h was effective on the isolation of PVMP. The highest frequency of callus formation and plant regeneration from the isolated protoplasts was obtained with NAA 2 mg/L and thidiazuron 0.01 mg/L. Furthermore, the results demonstrated that cell devision and plantlet regeneration was more frequent in the PVMP than in the MP of the same leaf or plant We, therefore, conclude that UM is an excellent experimental material for the callus formation and regeneration from isolated protoplasts.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.35-40
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• 1992

S. fradiae showed the highest acetanilide p-hydroxylation activity in the tested strains. And S. fradiae was well characterized genetically, especially with respect to tylosin production. Two mutants, which lost hydroxylation, were isolated in 140 regenerated colonies from protoplasts. In restriction enzyme digesion of total DNAs, isolation of giant linear plasmid DNA and determination of antibiotic resistances to chloramphenicol, tylosin, hygromycin B and mitomycin C, any differences among mutants and a wild type strain were not detected. These facts suggest that lesion on 6, 000 Kb chromosomal DNA was responsible for the lack of p-hydroxylation activity induced by protoplast formation and regeneration.

• Journal of Microbiology and Biotechnology
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• v.3 no.1
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• pp.24-30
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• 1993

In order to develop a novel yeast which produces the charateristic aroma of soy sauce, a protoplast fusion between Zygosaccharomyces rouxii WFS4 and Torulopsis versatilis IAM 4993 was carried out. Auxotrophic mutants as selective markers were obtained from Zygosaccharomyces rouxii and Torulopsis versatilis by treatment of N-methyl-N -nitro-N-nitrosoguanidine. The conditions of the protoplast formation and the regeneration for fusion were examined. The protoplast fusion using polyethylene glycol 4000 led to the fusion frequency of $4~5{\times}10^{-7}\;cells/ml$. Among fusants, a fusant ST723-F31 presented the best results in terms of the aromaticity of fragrance, the growth pattern, the resistance against salt and the degree of growth according to pH. It makes easy to control the production and the balance of aroma components so that it gives a good flavor, shortens the fermentation period and, simplifies the preparation process when using a bioreactor into which fusant is immobilized.

• KSBB Journal
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• v.6 no.3
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• pp.289-297
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• 1991

The insecticidal protein gene in the pKL-20-1 clone derived from Bacillus thuringiensis serovar. kurstaki plasmid was subcloned in the plant shuttle vector, pGA643. The 7.3 kb fragment was cloned in the BglII and Hpal sites of pGA643 vector and expressed in E. coli S17-1, which produced insecticidal proteins killing Bombyx mori larvae. The clone was named pHL-20. The protoplast formation, calli induction and plantlet regeneration of Nicotiana tabacum was carried out. A tremendous number of mesophyll protoplasts of N. tabacum were formed, up to 7$\times$105 protoplast per ml, for 20 hours in darkness in the enzyme solution of 0.5% cellulase and 0.1% macerosin, pH 5.8. The viabilities of the protoplasts were maintained above 80% for 6 days in the media containing 2mg/1 of NAA and 1mg/1 of kinetin. Calli were induced from the protoplasts and leaves of the N. tabacum on MS medium containing 0.5mg/1 BAP. Under the culture conditions the protoplasts underwent repeated cell division into calli. Plantlets were regenerated from callus cultures derived from protoplast and leaves. Shoots were induced in a medium containing 1mg/1 of BAP.

• The Korean Journal of Mycology
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• v.14 no.3
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• pp.215-223
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• 1986

Protoplasts of P. cornucopiae were reverted to normal hyphal growth and reversion frequency was $0.04{\sim}19%$. The complete medium stabilized with 0.6 M sucrose was most effective for regeneration of protoplasts. When hypertonic mushroom complete medium not containing agar was overlaid, regeneration frequency of protoplasts was the highest rate among the others of topagar. The protoplast reversion frequency and mycelial growth of P. cornucopiae were increased when various amino acids, nucleic acid components and vitamin compound were added to the hypertonic minimal medium. The relation between sources increasing reversion frequency and sources accelerating mycelial growth was similar in amino acids and nucleic acid components but it was different in vitamins. The protoplast reversion frequency showed the highest rate when all sources were added to the regeneration minimal medium. Microscopically, regeneration patterns of protoplasts showed formation of a bud-like structure, direct germination, yeast-like cell chain of the protoplast, and the production of both direct germ tube and yeast-like cell chain from a protoplast.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.130-136
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• 1993

Protoplasts of palisade cells were aseptically isolated from leaves of Nicotiono apicona Merxm. by the one step enzymatic method. Efficiency of colony formation were depended on cell density and light condition during incubation, but an intensity of 47 ft-c during a period of 2 weeks after isolation of the protoplasts in the Nagata and Takebe's medium promoted the planting efficiency. Protoplast - derived calli of N. africana can be differentiated into shoot when cultured on Murashige and skoog's medium containing IAA(0.Smg/$\ell$) and zeatin(5.0mg/$\ell$).

• Applied Biological Chemistry
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• v.42 no.1
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• pp.20-28
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• 1999

To improve Bacillus strains producing biopolymer, conditions for protoplast formation and regeneration were investigated in biopolymer producing Bacillus subtilis K-1 and lactose utilizing Bacillus coagulans. Bacillus subtilis K-1 mutant (SM-2) and Bacillus coagulans mutants (CM-12) were marked auxotrophic and antibiotics-resistant (SM-2) and an antibiotics-resistant mutants, respectively. To formate protoplasts derived from the mutants, conditions were established as follows. For B. subtilis mutant SM-2, its culture in mid-logarithmic phase was added with penicillin G (1.0 unit/ml) and further reacted for 1.5 hr. Cells were collected and then treated in lysis fluid (pH 7.0) containing 0.4 M sucrose and lysozyme $25\;{\mu}g/ml$ for 40 min at $37^{\circ}$. Protoplast formation was very successful (99.6%) and the ratio of cell wall regeneration was 2.4%. For Bacillus coagulans mutant CM-12, its mid-logarithmic phase culture was treated with penicillin G (0.3 unit/ml) and glycine (0.5%) for 1hr. Cells were collected and then resuspended in lysis buffer (pH 7.0) containing 0.6 M lactose and lysozyme $(300\;{\mu}g/ml)$ for 30 min at $37^{\circ}$. Protoplast formation was also successful (90.8%) and cell wall regeneration ratio was similar to SM-2 (2.2%). To improve regeneration frequency, regeneration medium was obtained as followed condition,. Cell wall regeneration was improved 2-4 folds with 5.1% for B. subtilis SM-2 and 10.3% for B. coagulans CM-12 when protoplasts mixed with soft top agar(0.4%) was overlaid onto trypticase soy broth medium containing 0.4 M sucrose, 0.7% casamino acid, 1% PVP, 25 mM $MgCl_2,\;25\;mM\;CaCl_₂$ and 1.5% agar.

• Korean Journal of Plant Tissue Culture
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• v.22 no.1
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• pp.7-11
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• 1995

Protoplasts were isolated from hypocotyl tissues of 5-day-old Brassica oleracea var capitata Green Challenger seedlings. Several media were used for protoplast culture and shoot regeneration. The shoot-regeneration rapacity of protoplast derived callus depended on the initial culture medium. Protoplasts were cultured in liquid medium (B5 medium supplemented with CaCl2, 2H2O 600mg/L, g1ucose 20g/L, D-mannito1 70g/L, NAA lmg/L, BA lmg/L, 2.4-D 0.25 mg/L)at 27$^{\circ}C$ under the dark After 5 to 10 days, cultlues were diluted with medium with a reduced osmotic stabilizer and then transferred to illuminated conditions. The culture medium was changed with the fresh medium at 7- to 10-day-intervals until the formation of microcallus. Hypocotyl protoplast-derived callus proliferated when transferred to MS medium supplemented with NAA lmg/L, BA 1mg/L and GA$_3$ 0.02mg/L. Upon transfer to MS basal medium without growth regulators, roots were produced. In an attempt to increase the regeneration frequency, 10g/L polyvinylpyrrolidone was added to the regeneration medium, but the shoot regeneration was mot improved. The regenerated whole plants were acclimated in a sterized soilless mixture(vermiculite 2;perlite 2;peat moss1) in a culture room.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.163-167
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• 1988

The conditions for the protoplast fusion of auxotrophic mutants of Penicillium verruculosum were determined. A preparation of commercial enzyme Novozym 234 was used to successfully isolate protoplast from the 20hr old mycelium of P. verruculosum. Under optimal condition, the protoplast yield ranged from 2.4$\times$10$^7$ to 3.0$\times$10$^7$ protoplasts from 400mg of damp mycelia of various auxotrophic mutant strains. The regeneration frequency ranged from 26.6 to 42.4% and the spontaneous reversion frequency of the protoplasts on the regeneration minimal medium was less than 10$^7$. The optimal concentration of PEG 6000 was 20%, and exposure of protoplasts to PEG for 10 min was found to be sufficient for protoplast fusion. Optimal pH of fusion mixture was deter-mined as 5.5 and l0mM of calcium chloride in fusion mixture effectively enhanced the protoplast fusion frequency. Under optimal condition, the fusion frequency between various auxotrophs ranged from 1.8$\times$10$^{-3}$ to 3.5$\times$0$^{-3}$.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.331-338
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• 2022

Sunflower (Helianthus annuus L.) protoplasts were isolated from seven-day-old etiolated hypocotyls of 10 A line and four-week-old fully expanded young leaves of PI 441983 line in vitro seedlings using an enzymatic method. Purified protoplasts were collected by filtration and floatation in sucrose solution. Semi-solid protoplast culture was performed using the L4 regeneration protocol with various culture media and plating densities to achieve the highest efficiencies for protoplast culture of hypocotyl and mesophyll protoplasts of 10 A and PI 441983 lines, respectively. The concentrations in liquid L'4M medium and different plating densities were evaluated in two types of cytokinins, the adenine-type 6-benzyladenine (BA) and the phenylurea-type thidiazuron (TDZ). The highest colony formation was achieved in both sunflower lines when 0.5 mgL^-1 BA and 0.5 mgL^-1 TDZ were applied with a high plating density (3 × 10⁵ protoplasts mL^-1). These conditions led to 38.45% and 39.40% colony formation for hypocotyl protoplasts of the 10 A line and mesophyll protoplasts of the PI 441983 line, respectively. Moreover, many hypocotyl protoplast-derived colonies developed into micro-calli. In addition, superior development of both sunflower protoplasts was observed with all plating densities when BA was used in combination with TDZ. This finding will be applicable to future sunflower hybrid production via somatic hybridization.