• Journal of Microbiology and Biotechnology
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• v.4 no.1
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• pp.24-29
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• 1994

To examine whether the signal sequence of Bacillus endo-1, 4-glucanase can act functionally in a yeast, a lower eucaryote, two recombinant plasmids were constructed and introduced into Saccharomyces cerevisiae: recombinant plasmid pGCMC10 containing the complete signal sequence of Bacillus endoglucanase, and pGCMC11 without the signal sequence. Secretion of endoglucanase into culture medium was obtained with the yeast transformant containing plasmid pGCMC10. The secreted endoglucanase was glycosylated and was apparently processed to be about 36 kilodaltons (KDa) and 43KDa proteins. The glycosylated endoglucanase from yeast transformant was more thermostable than the nonglycosylated endoglucanase from Escherichia coli transformant.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.83-87
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• 2015

Genetic transformation was affected by material of explant, age of callus, and medium of regeneration. Two rice seed cultivars (Ilpum and Baekjinju) and mediums were investigated in this study for enhancing regeneration of transgenic rice expressed AtBI-1 gene encoding the Arabidopsis thaliana Bax inhibitor. Regeneration rate of Ilpum rice transformant in gelrite of 5 and 8 g were 27.4% and 18.0%, respectively. In Baekjinju, regeneration rate of transformant was 5.4% and 4.3% in 5 and 8 g gelrite, respectively. The highest number of transformant plant in this study was regenerated from Ilpum cultivar on MS medium (30.4%) and was applied for the subsequent experiment. The callus regeneration rate of transformant were 40.7% in callus infection of up-side, it was higher regeneration then in the down-side (3.9%). The regeneration rate of callus of 25 days and 35 days were 14.7% and 38.6%, respectively. The most important application of this work is in genetic transformation of rice, particularly for improvement transgenic plant tissue culture protocol with high frequency of plant regeneration.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.333-336
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• 2001

An isolated phbC gene from Alcaligenes latus was reintroduced into the parent A. latus through the transformation process, and the effect of the amplified phbC gene on the biosynthesis of P(3-hydroxybutyrate-3-hydroxyvalerate) [P(3HB-3HV)] and P(3-hydroxybutyrate-4-hydroxybutyrate) [P(3HB-4HB)] in the transformant A. latus was investigated. The biosynthesis rate and content of the above copolymers increased up to 1.3-fold after enforcing its own phbC gene, and the molar fractions of 3HV and 4HB in P(3HB-3HV) and P(3HB-4HB) also changed remarkably from 35.0 to 48.0% and from 34.0 to 56.0%, respectively, showing a critical role of PHB synthase which catalyzes the polymerizing reactions between eiher 3HV or 4HB from precursor compounds and 3HB.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.340-347
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• 1995

We have used two kinds of P element constructs, Pc[(ry+)B] and p[(ry+)$\Delta$SX9], for genetic transformation by microinjection of D. melanogaster. Pc[(ry+)B] construct carrying the rosy gene within an autonomous P element was injected into a true M strain caring the ry506. mutation. The source of transposase for microinjection and transformation was provided by a P element helper plasmid designated p-$\Delta$2-3hs$\pi$, which was co-injected with nonautonomous P[(ry+)$\Delta$SX9] construct into same ry506 M strains. A dechorination method was adopted and 35 independent transformed lines were obtained froin 1143 G0 Injected (35/1143). About 20% of the injected embryos eclosed as adults. Among G0 eclosed flies, approximately 40% exhibited eye color that was similar to wild-type (ry+), but about 60% of fertile G0 transformed lines appeared to have no G1 transformants. Therefore it is unlikely that G0 expression requires integration of the rosy transposon into chromosomes. Pc[(ry+)B] and P[(ry+)$\Delta$SX9] constructs were found to be nearly same in the frequency of element-mediated transformation. On the basis of these results, nonautonomous P elements constructs could he used as same effective vectors in P element-mediated transformation for introducing and fixing genes in insect populations.

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.116-120
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• 1991

The transformant Bacillus subtilis ED213 carrying the pSO100 which cloned the cdd gene encoding cytidine deaminase (cytidine /2'-deoxycytidine aminohydrolase, EC 3.5.4.5, CDase) originated from wild type B. subtilis was cultivated in Spizizen minimal medium (SMM). To overcome poor expression of the cdd gene in SMM medium, the medium compositions and growth conditions were optimized. The optimized medium compositions and growth conditions were cytidine concentration of 80 mg/l, glycerol of 25 g/l, and $(NH_4)_2SO_4$ of 10 g/l, along with $37^{\circ}C$ and pH 7.0. The intracellular CDase production was increased 3 times from 1,000 unit/ml to 3,200 unit/ml, and extracellular CDase also increased from nearly undetectable amounts to 1,500 unit/ml. The cytidine concentration was signified as the most critical compositional factor for overproduction of CDase by increasing the cell density mainly in culture broth. The plasmids were more stable in cells that were grown in original SMM medium with stability of 90% compared to those grown in optimized SMM medium with stability of 80% after 48 hours cultivation. The most active amplification of plasmid was occurred in the logarithmic phase, which showed a value around four times higher than the initial copy number. In the exponential phase, the CDase production was closely related to the plasmid copy number along with the cell density. However, it was not accorded with cell density at the stationary phase.

• Journal of Microbiology
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• v.35 no.1
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• pp.61-65
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• 1997

A novel strategy was developed for isolating suppressors from sporulation-deficient mutants. The mutation in the BCY1 gene, which codes for the regulatory subunit of cAMP-dependent protein kinase, when homozygous, results in diploids being meiosis and sporulation deficient. Two plasmids, YCp-MAT.alpha. and YEp-SPOT7-lacZ, were introduced into MAT.alpha. BCY1$\^$+/ or MAT.alpha. bcy1 haploid cells. The transformant of the BCY1$\^$+/ haploid cell produced .betha.-galactosidase under nutrient starvation, but the bcy1 transformant did not. Using this system, the mutagenesis experiment performed on the bcy1 transformant strain resulted in a number of sporulation mutants that produced .betha.-galactosidase under nutrient starvation. One complementation group, sob1, was identified from the isoalted suppressor mutants and characterized as a single recessive mutation by tetrad analysis. Genetic analysis revealed that the sob1 mutation suppressed the sporulation deficiency, the failure to arrest at the G1 phase of the cell cecle, and the sensitivity to heat or nitrogen starvation caused by the bcy1 mutation. However, the sob1 mutation did not suppress the sporulation deficiency of ime1 and of ime2 diploids. These results suggest that the sob1 mutation affects a gene which functions as a downstream regulator in both meiosis and cell cycle regulation.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.222-228
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• 1992

Pleurotus florida was transformed by complementation of auxotrophic mutant using chimeric plasmid containing Flammulina velutipes leu 2 gene and pBR 322 replicon. Mycelial morphology of transformants was grown and compared on mushroom complete and minimal medium. Transformants were mated with monokaryon and their genetic recombination was investigated for the morphology of fruitbody and spore analysis. $Leu^+$ transformant showed same mating type of $A_1B_1$ as to the untransformed mutant. The transformant and the untransformed mutant were mated with monokaryon of which mating type is $A_2B_1$, respectively. Although fruitbody of the untransformed mutant was not produced, $leu^+$ transformant produced fruitbody. Spore analysis showed that leucine requiring spores from fruitbody of $leu^+$ transformant were diminished when compared with those of untransformed mutant.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.271-279
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• 1994

To develop a yeast strain which stably secretes both $\alpha$-amylase and glucoamylase and therefore is able to convert starch directly to ethanol, a mouse salivary $\alpha$-amylase cDNA gene with a yeast alcohol dehydrogenase I promoter has been introduced into the cell of a Saccharomyces diactaticus hybrid strain secreting only glucoamylase. To secrete both enzymes more stably without loss of the $\alpha$-amylase gene during a cell-multiplication, an integrating plasmid vector containing $\alpha$-amylase gene was constructed and introduced into the yeast cell. The results showed that the linearized form of the integrating vector was superior in the transformation efficiency and the rate of the expression of the $\alpha$-amylase gene than the circular type of the vector. The yeast transformant having a linearized plasmid vector exhibited higher mitotic stability than the yeast transformant habouring episomat plasmid vector. The transformant containing the linearized vector producing both $\alpha$-amylase and glucoamylase exhibited 2-3 times more amylolytic activity than the original untransformed strain secreting only glucoamylase.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.93-95
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• 2010

White rot fungi which have lignin degrading enzymes show high degrading activity to diverse recalcitrant compounds such as polycyclic aromatic compounds, dyes, explosives and endocrine disrupting chemicals. We have examined decolorizing activity of dyes by Phlebia tremellosa and two transformants which had genetically transformed using laccase or manganese peroxidase (MnP) gene. In case of methyl green, wild type strain showed 50% decolorization while laccase transformant (TF2-1) and MnP transformant (T5) showed more than 90% decolorization on day 3. Remazol brilliant blue R(RBBR) was decolorized up to 85% by two transformants while the wild type showed 67% decolorization on day 3. Transformants TF2-1 and T5 both showed increased laccase and MnP activity respectively during the whole growing phase.

• Journal of Microbiology
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• v.45 no.3
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• pp.213-218
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• 2007

Trametes versicolor has a lignin degrading enzyme system, which is also involved in the degradation of diverse recalcitrant compounds. Manganese-dependent peroxidase (MnP) is one of the lignin degrading enzymes in T. versicolor. In this study, a cDNA clone of a putative MnP-coding gene was cloned and transferred into an expression vector (pBARGPE1) carrying a phosphinothricin resistance gene (bar) as a selectable marker to yield the expression vector, pBARTvMnP2. Transformants were generated through genetic transformation using pBARTvMnP2. The genomic integration of the MnP clone was confirmed by PCR with bar-specific primers. One transformant showed higher enzyme activity than the recipient strain did, and was genetically stable even after 10 consecutive transfers on non-selective medium.