• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.317-323
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• 2012

This study was performed to elucidate the anticancer activities and the mechanism of chloroform fractions from cultivated Orostachys japonicus (CFCOJ) in human colon cancer cells. CFCOJ markedly decreased viable cell numbers in both a dose-dependent and time-dependent manner within SW480 cells. Cell death induced by CFCOJ increased cell populations in the sub-G1 phase, as well as the formation of apoptotic bodies, nuclear condensation, and induced DNA fragmentation. CFCOJ-induced apoptosis was associated with the activation of initiator caspase-8 and -9, as well as the effector caspase-3. CFCOJ also stimulated Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. CFCOJ increased the expression of the proapoptotic protein, Bax, and decreased the expression of the antiapoptotic protein, Bcl-2. These results indicate that CFCOJ exert anticancer effects on human colon cancer SW480 cells through a caspase-dependent apoptotic pathway.

• Journal of Life Science
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• v.20 no.11
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• pp.1697-1703
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• 2010

Asarum consists of low-growing herbs and is a genus in the Aristolochiaceae family with species found in the north temperate zones with most species in Asia. We evaluated the nine taxa with the trnL - trnT region of the chloroplast genome to estimate phenotypic relationships within genus Asarum in Korea. Alignment of the DNA sequences required the addition of numerous gaps. Sequence variation within the Asarum was mostly due to nucleotide inserts/deletions, although several indels and inserts were found. Another source of sequence divergence was length variation due to stretches of short repeats that occur at the trnL - trnT region in all the Asarum. A + T content for nine Korean species of genus Asarum ranged between 74.7% and 78.3%. These values were higher than those for the angiosperm alignments of the total trnL and trnT region (64.5~67.1%). Within genus Asarum, A. patens was strikingly different from the others in the three phylogenetic analyses (MP, ML, and NJ). However, some internal nodes were poorly supported. Within Korean Asarum, four species were unsolved portions. Possible reasons for the striking non-congruence between the previous morphological traits and the trnL - trnT based on phylogeny were discussed.

• Food Science and Preservation
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• v.20 no.5
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• pp.705-711
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• 2013

Gamma amino butyric acid (GABA), known as a non-protein amino acid and major inhibitory neurotransmitter in the brain, has several functional properties such as neurotransmission, induction of hypotension, tranquilizer, and diuretic effects. The purpose of this study was to isolate and identify lactic acid bacteria, producing high GABA in fermented soy curd. Thirty-two strains of tofu-forming lactic acid bacteria were isolated from kimchi which a traditional Korean food fermented with many kind of microorganism. Among 32 strains, four strains (strain No. 10, 104, 214, 249) formed firm soycurd. In order to select lactic acid bacteria having high GABA producing potential, the isolated strains were cultured in the soymilk and fermented for 48 hr at $37^{\circ}C$. A strain No. 383, which showed highest GABA contents in fermented soycurd, was identified as L. sakei by 16S rDNA sequencing and API analysis, and named as L. sakei 383. L. sakei 383 showed optimal growth up to 24 hr at $35^{\circ}C$ in MRS broth. The optimal time and temperature for GABA production were 18 hr and $35^{\circ}C$ in soymilk. In the optimal condition time and temperature, GABA content of fermented soycurd by L. sakei 383 was 8.65 mg/100 g.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.54-58
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• 2006

The genetic analyses of Acanthopanax senticosus Harms from Korea, China and Russia, were made by comparing the internal transcribed spacer (ITS) sequences of the nuclear ribosomal DNA. The ITS region of A. senticosus was amplified by polymerase chain reaction (PCR) using the universal primers and then directly sequenced. The length of the ITS region including 162 bp 5.85 rRNA gene ranged from 608 bp (for Korean and Chinese) to 611 bp (for Russian). The G+C content of ITS region were 60.20% for Korean and Chinese plants and 60.06% for Russian plants. Sequence comparisons indicated that ITS regions of A. senticosus from Korea and China were identical, whereas the ITS sequence of A. senticosus from Russia showed 99.2% homology with the plants from Korea. Variation in sequences were attributable to 5 bp substitution such as transversion or insertion events. These results suggested that A. senticosus Harms from Korea and China were closely related in phylogenetic relationship compared to Russian. In addition, A. senticosus Harms were more similar to Kalopanax pictus than A. sessiliflorus in their ITS sequences.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.1-8
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• 1993

lntergeneric hybrids formed between Aspergillus niger and Penicillium verruculosum were obtained by nuclear transfer technique. Nuclei isolated from wild type and auxotrophic mutants of donor strains were transferred into the protoplasts of different auxotrophic mutants as recipient strains. Several auxotrophic mutants were isolated from conidiospores of the two strains mutagenized with ultraviolet and N-methyl-N'-nitrosoguanidine. Optimal conditions for formation of intergeneric hybrids were investigated. Frequencies of intergeneric hybrid formation by nuclear transfer were $7{\times}10^{5}~1{\times}10^{5}$. From observations of genetic stability. DNA content. nuclear stain and conidial size. it was suggested that their karyotypes are aneuploid. In addition. the hybrids possess the 1.1~2.3-fold higher cellulase activities than those of parental strains. It was also revealed that some hybrids had different isozyme patterns compared to those of parental strains by CMCase and $\beta$-glucosidase activity assays.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.188-196
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• 1988

Intergeneric or intraspecific protoplast fusion between Saccharomyces cerevisiae X-2180-1A, Candida pseudotropicalis ATCC 8619 and CBS 607 was attempted to produce ethanol from lactose containing materials. Teh intergeneric fusion frequency between Saccharomyces cerevisiae X-2180-1A (ade rho) and Candida pseudotropicalis CBS 607 (his met) was $1.0\times 10^{-5}$. These values exhibited approximately 2-3.5 fold increase when compared with fusion frequency obtained without the treatment of bovine serum albumin, myoinositol and ergosterol, suggesting that these compounds may improve intergeneric of intraspecific protoplast fusion. Nuclear fusion appears to occur in fusants between intergenera(S. cerevisiae+C. pseudotropicalis) and intraspecies (C. pseudotropicalis strains) as strongly suggested by DNA content, nuclear staining, comparison of survival rate to UV light and isolation of recombinants after mitotic segragation. It was also found that alcohol production from intraspecific hybrids was somewhat increased when compared with that from their parents.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.55-64
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• 1990

Cell volume and DNA contents of the fusants were similar to those of parents. Genetic stability of the fusants was increased when they were cultured on minimal medium (MM) rather than on complete medium (CM), and the fusants were stabilized by subculturing 7 generations each 7 day on MM agar. The finally selected fusants after being cultured for 6 months on CM were stable without segregation. The fusants could also form nuclein and ascospores, and show red and pink colors by the test of TTC colorization. Assimilability and fermentability of carbon sources of the fusants were similarto those of parents. The tolerance of KCl, NaCl, sodium propionate and cycloheximide showed the traits of one strain of parents. When the fusants were cultured for 72 hr and 60 hr in the medium containing 20% glucose and sucrose, respectively, the yield of ethanol for FWKS 260 was reached to 9.6 v/v% and 9.8v/v%, respectively. The sensitive strain Kyokai 7 was found to be killed entirely after cultivation of 48 hr by the killer toxin from the fusants. The recipient S 29 and Kyokai 7 were found to have neither L nor M dsRNA plasmid. However, K 52 and fusants had both L and M dsRNA plasmid of 4.7 kb and 2.5 kb, respectively. The curants treated by heat and cycloheximide did not contain M dsRNA plasmid, but had large amounts of L dsRNA plasmid of those of killer yeasts.

• Journal of Life Science
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• v.13 no.6
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• pp.871-878
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• 2003

A marine bacterium (strain BKl) that produces extracellular enzymes capable of decomposing complex polysac-charides, such as agar, chitin, carboxymethylcellulose, xylan and mannan, was isolated from the marine red alga Porphyra dentata. Strain BKl was gram-negative, aerobic, catalase- and oxidase-positive, polarly flagellated bacilli that produce gelatinase and urease, but not decarboxylases. The G+C content of the DNA was 51.6 mol%. The major isoprenoid quinone component was identified as an ubiquinone-8, and the major cellular fatty acids were C16:0, C16:1 w6c and C18:1 w7c. Comparative 16S rRNA sequence analysis placed strain BK1 with members of the genus Pseudomonas. On the basis of phenotypic and genotypic data, the strain BK1 was shown to be a member of the subgroup of Pseudomonas, and named as Pseudomonas sp. BK1.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.277-281
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• 2008

HIV affects many organ systems. Patients with HIV infection have substantially increased risk of developing various cancers, primarily by opportunistic infection with oncogenic viruses due to their immunocompromised status. However, extensive evidence also indicates that the viral protein, Tat itself, may playas a major factor in the development of AIDS-related neoplasms. The molecular mechanism underlying Tat's oncogenic activity may include deregulation of cellular genes. Therefore, in this study, we examined the effect of HIV-l Tat on CD99 as one of the target cellular genes, which is a well-known tumor marker in several cancers. By using established HeLa clones that are stably expressing Tat, we found that CD99 is upregulated by endogenous Tat, whereas STAT3 is down regulated. Upon the screening of genes differentially expressed between Tat-stable cells and the control cells by using the gene fishing technique, DEG, we detected 3 genes which expression is affected by the presence of Tat. Furthermore, the methylation specific PCR analysis of the stably Tat expressing cell lines revealed that the CD99 promoter is de methylated in the presence of Tat. Taken together, these results open a potential role of CD99 in AIDS-related oncogenesis via epigenetic regulation by HIV-1 Tat.

• KSBB Journal
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• v.21 no.2
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• pp.144-150
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• 2006

The exploitation of metagenome, the access to the natural extant of enormous potential resources, is the way for elucidating the functions of organism in environmental communities, for genomic analyses of uncultured microorganism, and also for the recovery of entirely novel natural products from microbial communities. The major breakthrough in metagenomics is opened by the construction of libraries with total DNAs directly isolated from environmental samples and screening of these libraries by activity and sequence-based approaches. Screening with activity-based approach is presumed as a plausible route for finding new catabolic genes under designed conditions without any prior sequence information. The main limitation of these approaches, however, is the very low positive hits in a single round of screening because transcription, translation and appropriate folding are not always possible in E. coli, a typical surrogate host. Thus, to obtain information about these obstacles, we studied the genetic organization of individual URF's(unidentified open reading frame from metagenome sequenced and deposited in GenBank), especially on the expression factors such as codon usage, promoter region and ribosome binding site(rbs), based on DNA sequence analyses using bioinformatics tools. And then we also investigated the above-mentioned properties for 4100 ORFs(Open Reading Frames) of E. coli K-12 generally used as a host cell for the screening of noble genes from metagenome. Finally, we analyzed the differences between the properties of URFs of metagenome and ORFs of E. coli. Information derived from these comparative metagenomic analyses can provide some specific features or environmental blueprint available to screen a novel biocatalyst efficiently.