• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.133-139
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• 1994

Two human lactoferrin expression vectors(pCChcLf and pCChcLf-1) were constructed using rat $\beta$-casein gene and human lactoferrin cDNA. The recombinant DNAs containing human lactoferrin cDNA were microinjected into the fertilized eggs of hybrid mice (BDF1 : C57BL$\times$DBA) and the DNA-injected eggs were treansferred into the oviducts of foster mothers. Genomic DNAs were isolated from the tails of mice born from the microinjected eggs and analyzed by Southern blot analysis. As a result, 5 and 9 transgenic mice with CChcLf and CChcLf-1 gene were produced, respectively. To determine tissue-specificity of transgene expression, Northern blot analysis was performed. Female transgenic mice were killed at day 10 of lactation and total RNAs from various tissues were isolated. Based on Northern blot analysis, it was shown that transgene was mainly expressed in the mammary glands of transgenic mice. In addition, the human lactoferrin in milk was detected by enzyme-linked immunosorbent assay. For this study, milk was obtained from the mammary glands of the transgenic mice at day 10 of lactation. In line #2 of CChcLf and line #7 of CChcLf-1 transgenic mice, human lactoferrin was secreted into the milk at concentration levels of 340ng/ml and 60ng/ml, respectively.

• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.353-359
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• 1994

Pseudomonas sp. P20 was a bacterial isolate which has the ability to degrade 4-chlorobi- phenyl(4CB) to 4-chlorobenzoic acid via the process of meta-cleavage. The recombinant plasmid pCK1 was constructed by insetting the 14-kb EcoRI fragment of the chromosomal DNA containing the 4CB-degrading genes into the vector pBluescript SK(+). Subsequently, E. coli XL1-Blue was transformed with the hybrid plasmid producing the recombinant E. coli CK1. The recombinant cells degraded 4CB and 2,3-dihydroxybiphenyl(2,3-DHBP) by the pcbAB and pcbCD gene products, respectively. The pcbC gene was expressed most abundantly at the late exponential phase in E. coli CK1 as well as in Pseudomonas sp. P20, and the level of the pcbC gene product, 2,3-DHBP dioxygenase, expressed in E. coli CK1 was about two-times higher than in Pseudomonas sp. P20. The activities of 2,3-DHBP dioxygenase on catechol and 3-methylcatechol were about 26 to 31% of its activity on 2,3-DHBP, but the enzyme did not reveal any activities on 4-methylcatechol and 4-chlorocatechol.

• Journal of Ecology and Environment
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• v.34 no.4
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• pp.393-400
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• 2011

The effects of the ectomycorrhizal fungus Pisolithus tinctorius and cadmium (Cd) on physiological properties and Cd uptake by Populus alba ${\times}$ glandulosa was investigated under greenhouse conditions. Cd treatment decreased the photosynthetic rate ($P_N$) of both non-mycorrhizal (NM) plants (16.3%) and ectomycorrhizal (ECM) plants (11.5%). In addition, the reduction in total dry weight by Cd treatment was greater in ECM plants (24.3%) than that in NM plants (17.6%). Mycorrhizal infection increased the $P_N$ and transpiration rate in both control and Cd-treated plants. Cd treatment increased superoxide dismutase (SOD) activity and decreased glutathione reductase activity, and the increase of SOD activity by Cd treatment was greater in NM plants (40.3%) than that in ECM plants (3.7%). Thiol content increased in both NM and ECM plants treated with Cd solution, and the increase in thiol content in NM plants (43.9%) was greater than that of ECM plants (15.6%). Cd uptake in the leaves, stems, and roots of ECM plants was 69.9%, 167.2% and 72.8%, respectively, higher than in the NM plants. However, the increase in Cd uptake ability of ECM plants resulted in a reduction in dry weight.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.346-353
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• 2005

A 50-kb chromosome DNA region was isolated from Streptomyces kanamyceticus by screening the fosmid genomic library, using the 16S rRNA methylase gene (kmr) as a probe. Sequence analysis of this region revealed 42 putative open reading frames (ORFs), which included biosynthetic genes such as genes responsible for 2-deoxystreptamine (2­DOS) biosynthesis as well as genes for resistance and regulatory function. Also, the kanamycin acetyltransferase gene (kac) was characterized by in vitro enzyme assay, which conferred E. coli BL21 (DE3) with 10, 50, and 80-times higher resistance to kanamycin A, tobramycin, and amikacin, respectively, than the control strain had, thus strongly indicating that the isolated gene cluster is very likely involved in kanamycin biosynthesis. This work provides a solid basis for further elucidation of the kanamycin biosynthesis pathway as well as the productivity improvement and construction of new hybrid antibiotics.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.165-169
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• 1997

Two gentamicin resistance R plasmids, pGM5 and pGM6, containing aacC2 gene were selected from environmental isolates. The gentamicin resistance determinants of R plasmids were cloned into the BamHI site of pUC18. Restriction enzyme map of inserted region of recombinant plasmids, pSYS and pSY6, and PCR results indicated that Tn3 sequence was located upstream of gentamicin resistance gene. Based on the restriction maps and susceptibility tests, it was concluded that the sequence of bla and 3' inverted repeat of Tn3 play a important roles in the expression of gentamicin resistance gene.

• Journal of Microbiology
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• v.37 no.1
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• pp.35-40
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• 1999

Sporulation-specific glucoamylase (SGA) gene was isolated from genomic library of Saccharomyces diastaticus 5114-9A by using glucoamylase non-producing mutant of S. diastaticus as a recipient. When the glucoamylase activities of culture supernatant, periplasmic, and intracellular fraction of cells transformed with hybrid plasmid containing SGA gene were measured, the highest activity was detected in culture supernatant. SGA produced by transformant and extracellular glucoamylase produced by S. diastaticus 5114-9A differed in enzyme characteristics such as optimum temperature, thermostability, and resistance to SDS and urea. But the characteristics of SGA produced by sporulating yeast cells and vegetatively growing transformants were identical.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.273-279
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• 1992

Protoplasts isolated from leaf mesophyll tissues of Populus koreana ${\times}$ P. nigra var. italica were fused with those of P. euramericana cv. Guardi. Well expended healthy leaves of 5 to 7 week-old-plantlet grown in vitro were used as source materials. Leaves from P. koreana ${\times}$ P. nigra var. italica and P. euramericana cv. Guardi were digested in enzyme solution I (2.0% Cellulase, 1.2% Hemicellulase, 0.4% Macrozyme, 2.0% Driselase, 0.05% Pectolyase ; w/v) and enzyme solution II (1.0% Cellulase, 1.2% Hemicellulase, 0.4% Macrozyme, 2.0% Driselase, 0.05% Pectolyase ; w/v), respectively, The highest frequency of fusion among the protoplasts originated from the two source materials was approximately 21% using 40% PEG or 15% dextran. In addition, fusion frequency was enhanced by incorporating 30mM of $Ca^{2+}$ in eluting solution at pH 10.5. Dividing cells and/or mint-calli were obtained by culturing the fusion products in a liquid 8p-KM medium supplemented with 0.6M sucrose, $0.45{\mu}M$ 2, 4-D, and $0.5{\mu}M$ BA. Shoots were regenerated from the fusion product-derived calli after culture on MS medium containing $5.0{\mu}M$ zeatin. To verify the putative hybrid or cybrid, SDS-PAGE was carried out. From the 24 regenerants, just two plants showed intermediate protein band patterns compared with those of the original source plants.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1319-1326
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• 2007

Fructose-1,6-bisphosphatase (FBP1) is a key regulatory enzyme of gluconeogenesis that catalyzes the hydrolysis of fructose-1,6-bisphosphate to generate fructose-6-phosphate and inorganic phosphate. Deficiency of fructose-1, 6-bisphosphatase is associated with fasting hypoglycemia and metabolic acidosis. The enzyme has been shown to occur in bacteria, fungi, plants and animals. The bovine FBP1 gene was cloned and characterized in this study. The full length (1,241 bp) FBP1 mRNA contained an open reading frame (ORF) encoding a protein of 338 amino acids, a 63 bp 5' untranslated region (UTR) and a 131 bp 3' UTR. The bovine FBP1 gene was 89%, 85%, 82%, 82% and 74% identical to the orthologs of pig, human, mouse, rat and zebra fish at mRNA level, and 97%, 96%, 94%, 93% and 91% identical at the protein level, respectively. This gene was broadly expressed in cattle with the highest level in testis, and the lowest level in heart. An intronic single nucleotide polymorphism (SNP) (A/G) was identified in the $5^{th}$ intron of the bovine FBP1 gene. Genotyping of 133 animals from four beef breeds revealed that the average frequency for allele A (A-base) was 0.7897 (0.7069-0.9107), while 0.2103 (0.0893-0.2931) for allele B (G-base). Our preliminary association study indicated that this SNP is significantly associated with traits of Average Daily Feed Intake (ADFI) and Carcass Length (CL) (p<0.01). In addition, the FBP1 gene was assigned on BTA8 by a hybrid radiation (RH) mapping method.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.597-604
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• 2014

$\small{D}$-Phenylglycine aminotransferase ($\small{D}$-PhgAT) from Pseudomonas stutzeri ST-201 is useful for enzymatic synthesis of enantiomerically pure $\small{D}$-phenylglycine. However, its low protein solubility prevents its application at high substrate concentration. With an aim to increase the protein solubility, the N-terminus of $\small{D}$-PhgAT was genetically fused with short peptides ($A_1$ ${\alpha}$-helix, $A_2$ ${\alpha}$-helix, and ALAL, which is a hybrid of $A_1$ and $A_2$) from a ferredoxin enzyme of a halophilic archaeon, Halobacterium salinarum. The fused enzymes $A_1$-$\small{D}$-PhgAT, $A_2$-$\small{D}$-PhgAT, and ALAL-$\small{D}$-PhgAT displayed a reduced pI and increased in solubility by 6.1-, 5.3-, and 8.1- fold in TEMP (pH 7.6) storage, respectively, and 5-, 4.5-, and 5.9-fold in CAPSO (pH 9.5) reaction buffers, respectively, compared with the wild-type enzyme (WT-$\small{D}$-PhgAT). In addition, all the fused $\small{D}$-PhgAT displayed higher enzymatic reaction rates than the WT-DPhgAT at all concentrations of L-glutamate monosodium salt used. The highest rate, $23.82{\pm}1.47$ mM/h, was that obtained from having ALAL-$\small{D}$-PhgAT reacted with 1,500 mM of the substrate. Moreover, the halophilic fusion significantly increased the tolerance of $\small{D}$-PhgAT in the presence of NaCl and KCl, being slightly in favor of KCl, where under the same condition at 3.5 M NaCl or KCl all halophilic-fused variants showed higher activity than WT-$\small{D}$-PhgAT.

• Journal of Life Science
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• v.22 no.2
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• pp.142-147
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• 2012

The sporulation-specific glucoamylase (SGA) of Saccharomyces diastaticus is known to be produced in the cytoplasm during sporulation. For the purpose of proving that SGA has secretory potential, we constructed a hybrid plasmid, pYESC25, containing the promoter and the putative signal sequence of the SGA fused in frame to the endo-1,4-${\beta}$-D-glucanase (CMCase) gene of Bacillus subtilis without its own signal sequence. The recipient yeast strain of S. diastaticus YIY345 was transformed with the hybrid plasmid. CMCase secretion from S. diastaticus harboring pYESC25 into culture medium was confirmed by the formation of yellowish halos around transformants after staining with Congo red on a CMC agar plate. The transformant culture was fractionated to the extracellular, periplasmic, and intracellular fraction, followed by the measurement of CMCase activity. About 63% and 13% enzyme activity were detected in the culture supernatant (extracellular fraction) and periplasmic fraction, respectively. Furthermore, ConA-Sepharose chromatography, native gel electrophoresis, and activity staining revealed that CMCase produced in yeast was glycosylated and its molecular weight was larger than that of the unglycosylated form from B. subtilis. Taking these findings together, SGA has the potential of secretion to culture medium, and the putative signal sequence of SGA can efficiently direct bacterial CMCase to the yeast secretion pathway.