• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.36-36
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• 2003

In the present study, growth performances of the offspring from selected brood line were compared to those of the offspring from non-selected brood line of red sea bream. Offspring groups were mass produced separately from two brood lines, selected and non-selected Korean strain. Selected brood line have been selected by fish size for four generations (upper 5∼30% per generation) and non-selected brood line is the second generation of wild population at south sea in Korea. There's no significant difference in body length between offspring from selected and non-selected brood line during early growing stage (until 96-days old). However, offspring from selected brood line had superior body weight growth than offspring from non-selected brood line. At sea cages rearing trials with communal stocking, Offspring from selected brood line showed significantly better performance in body weight, body length, weight gain, specific growth rate and feed consumption (but not in feed conversion ratio) than offspring from non-selected brood line. At 24 months old, offspring from selected brood line grew faster 1.10 times in body length and 1.41 times in body weight than offspring from non selected brood line. The response to selection when compared to a non-selected line is on average of 10% in weight per generation at 24 months old.

• Mycobiology
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• v.38 no.1
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• pp.17-25
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• 2010

The common split-gilled mushroom, Schizophyllum commune is found throughout the world on woody plants. This study was initiated to evaluate conditions for favorable vegetative growth and to determine molecular phylogenetic relationship in twelve different strains of S. commune. A suitable temperature for mycelial growth was obtained at $30^{\circ}C$. This mushroom grew well in acidic conditions and pH 5 was the most favorable. Hamada, glucose peptone, Hennerberg, potato dextrose agar and yeast malt extract were favorable media for growing mycelia, while Lilly and glucose tryptone were unfavorable. Dextrin was the best and lactose was the less effective carbon source. The most suitable nitrogen sources were calcium nitrate, glycine, and potassium nitrate, whereas ammonium phosphate and histidine were the least effective for the mycelial growth of S. commune. The genetic diversity of each strain was investigated in order to identify them. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 129 to 143 bp and 241 to 243 bp, respectively. The sequence of ITS1 was more variable than that of ITS2, while the 5.8S sequences were identical. A phylogenetic tree of the ITS region sequences indicated that the selected strains were classified into three clusters. The reciprocal homologies of the ITS region sequences ranged from 99 to 100%. The strains were also analyzed by random amplification of polymorphic DNA (RAPD) with 20 arbitrary primers. Twelve primers efficiently amplified the genomic DNA. The number of amplified bands varied depending on the primers used or the strains tested. The average number of polymorphic bands observed per primer was 4.5. The size of polymorphic fragments was obtained in the range of 0.2 to 2.3 kb. These results indicate that the RAPD technique is well suited for detecting the genetic diversity in the S. commune strains tested.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.758-761
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• 2001

In this study, the nar promoter of E. coli was characterized to see whether the nar promoter cloned onto pBBR122 can be used as an expression promoter of gram negative microbes. For this purpose, a plasmid with lacZ gene expressing ${\beta}-galactosidase$ instead of the structural genes of nar operon in a gram negative host strain(Agrobacterium.tumefaciens) was used to simplify an assay of induction of the nar promoter. The following effects were investigated to find optimal conditions: methods of inducing the nar promoter, optimal nitrate concentration, maximally inducing the nar promoter, the amount of expressed ${\beta}-galactosidase$ and induction ratio(specific ${\beta}-galactosidase$ activity after maximal induction/specific ${\beta}-galactosidase$ activity before induction). The following results were obtained from the experiments: the growth of Agrobacterium with E.coli nar promoter was not much affected by nitrate concentration in the shake-flask; induction of nar promoter was optimal when Agrobacterium was grown in the presence of 1% nitrate ion at the beginning of culture and when overnight culture was completely grown in the shake-flask before being transferred to other shake-flask; the amount of ${\beta}-galactosidase$ per cell and per medium volume was maximal when Agrobacterium was grown under aerobic condition to $OD_{600}$ of 1.7; then the nar promoter was induced under microaerobic and anaerobic condition made by lowering dissolved oxygen level(DO). After 2-3h of induction in the YEP medium selected as a main culture medium, the specific ${\beta}-galactosidase$ activity became about 17,000 Miller units in the fermentor cluture.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.415-419
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• 2006

The epoxide hydrolase (EH) of Rhodotorula glutinis which has a high enantioselectivity against aromatic epoxide substrates was expressed to high levels in Escherichia coli based on codon usage. We analysed the Preference of codon usage between the yeast, R. glutinis, and bacteria, E. coli. E. coli, Rosetta(DE3)pLysS, harbors pRARE plasmid with tRNA genes for rare-codons was employed as a host strain. The recombinant E. coli expressing R. glutinis EH showed an enhanced enantioselective hydrolysis activity toward racemic styrene oxide. Enantiopure (S)-styrene oxide with a high enantiopurity of 99% ee (enantiomeric excess) was obtained from racemic substrates.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.568-570
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• 2003

The Hyoscyamus niger hyoscyamine $6{\beta}-hydroxylase$ (H6H, EC 1.14.11.11) gene was introduced into the genome of a Scopolia parviflora by the binary vector system using the disarmed Agrobacterium rhizogenes strain KCTC 2703. Expression of H6H enzyme which are involved in alkaloids pathway by western blot analysis using proteins extracted from leaf, stem flower, branch root and main root were examined The enzyme expression was found only in the roots, with no expression in leaf, stem and flower. The alkaloids contents were the most higher in root and then leaf and stem has very small amount of alkaloid contents were analyzed by HPLC. The expression level of H6H in transgenic plants were two or more times than wild type plants. In transgenic plant which constitutively expresses H6H enzyme, high concentration of scopolamine was accumulated.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.569-574
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• 2015

Arthrospira platensis has high lipid and pigment (such as chlorophyll and carotenoid) contents and thus evaluated as an important resource in functional food production. The cell growth rate and pigment concentration of EM24 increased by approximately 1.2-fold than those of the wild-type strain (WT). Fluorescence intensity levels in EM24, which were quantified with a lipid triolein standard curve, also increased by approximately 1.5-fold than those in WT (62.9 mg/Lvs. 38.9 mg/L). The analysis of fatty acid profiles indicated that the gamma-linoleic acid level in EM24 increased by 1.5-fold than that in WT.

• Biomedical Science Letters
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• v.12 no.2
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• pp.99-104
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• 2006

Present study was performed to investigate the host-parasite relationship of the Korean Trichinella isolate (KTI). In the experiment to observe the infectivity of KTI to several kinds of animals, the reproductive capacity index (RCT) was highest in cats, and that in mice, hamsters and rats was followe4 in descending order. However, birds, i.e. wild goose and chicken, did not infect with KTI. The number of larvae per a gram of muscle (LPG: 377) was highest in the tongue of cats experimentally infected with KTI larvae. LPG in the diaphragm, anterior leg, back, posterior leg and abdominal muscles were 313, 246, 234, 225 and 170 respectively. Muscle larvae recovered at 55 days after infection were revealed the highest infectivity (RCI: 137.2) in mice. RCI was comparatively low in the mice infected with less than 25 day-old and more than 300 day-old larvae. In the experiment to observe the susceptibility of KTI by the mouse strain, ICR (RCI: 137.2), C57BL/6 (RCI: 108.8), DBA/2 (RCI: 107.1), C3H (RCI: 98.7), BALB/c (RCI: 96.9), FVB (RCI: 96.1) and B6C3F1 (RCI: 85.3) were very susceptible. However, BDF1 (RCI: 57.7) and CBA (RCI. 57.1) were revealed the moderate susceptibility, and B6CBAF1 (RCI: 23.1) was shown the lowest. The infection sites of adults were posteriorly transferred in the small intestine of experimental mice according to the infection periods of muscle larvae. The infection characteristics of KTI observed in this study may be useful as the basic data in the advanced studies, furthermore in the study of other Trichinella isolates.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.367-374
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• 2014

Genomes contain a large number of unique genes which have not been found in other species. Although the origin of such "orphan" genes remains unclear, they are thought to be involved in species-specific adaptive processes. Here, we analyzed seven orphan genes (MoSPC1 to MoSPC7) prioritized based on in planta expressed sequence tag data in the rice blast fungus, Magnaporthe oryzae. Expression analysis using qRT-PCR confirmed the expression of four genes (MoSPC1, MoSPC2, MoSPC3 and MoSPC7) during plant infection. However, individual deletion mutants of these four genes did not differ from the wild-type strain for all phenotypes examined, including pathogenicity. The length, GC contents, codon adaptation index and expression during mycelial growth of the four genes suggest that these genes formed during the evolutionary history of M. oryzae. Synteny analyses using closely related fungal species corroborated the notion that these genes evolved de novo in the M. oryzae genome. In this report, we discuss our inability to detect phenotypic changes in the four deletion mutants. Based on these results, the four orphan genes may be products of de novo gene birth processes, and their adaptive potential is in the course of being tested for retention or extinction through natural selection.

• The Plant Pathology Journal
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• v.33 no.2
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• pp.193-205
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• 2017

Histone methylation plays important roles in regulating chromatin dynamics and transcription in eukaryotes. Implication of histone modifications in fungal pathogenesis is, however, beginning to emerge. Here, we report identification and functional analysis of a putative JmjC-domain-containing histone demethylase in Magnaporthe oryzae. Through bioinformatics analysis, we identified seven genes, which encode putative histone demethylases containing JmjC domain. Deletion of one gene, MoJMJ1, belonging to JARID group, resulted in defects in vegetative growth, asexual reproduction, appressorium formation as well as invasive growth in the fungus. Western blot analysis showed that global H3K4me3 level increased in the deletion mutant, compared to wild-type strain, indicating histone demethylase activity of MoJMJ1. Introduction of MoJMJ1 gene into ${\Delta}Mojmj1$ restored defects in pre-penetration developments including appressorium formation, indicating the importance of histone demethylation through MoJMJ1 during infection-specific morphogenesis. However, defects in penetration and invasive growth were not complemented. We discuss such incomplete complementation in detail here. Our work on MoJMJ1 provides insights into H3K4me3-mediated regulation of infection-specific development in the plant pathogenic fungus.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.192-197
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• 1994

Pseudomonas fluorescens which is able to utilize malonate as a sole carbon source was found to contain a novel 60 kb plasmid, which encodes the genes for the proteins to assimilate malonate, including malonate decarboxylase and acetyl-CoA synthetase. The evidence is as follows: The Pseudomonas cured with mitomycin C was unable to grow on malonate-medium as well as it lost plasmid. The plasmid isolated from the Pseudomonas could be introduced into E. coli strain JM103 and DH1 by transformation. The transformed E. coli was able to grow on malonate-medium and could transmit its plasmid back to the cured P. fluorescens by conjugation. The existence of the plasmid in the transformed E. coli was confirmed by hybridization with a labeled probe prepared from 12 kb segment of the plasmid. Dot hybridization showed that the copy number of the plasmid in the transformed E. coli is at least 13 times higher than in the wild type P. fluorescens. The two key enzymes, malonate decarboxylase and acetyl-CoA synthetase, were inducible by malonate in the transformed E. coli.