• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.1111-1114
• /
• 2001

An extracellular fibrinolytic-enzyme-producing bacterium was isolated from Doen-Jang, a Korean traditional fermented flood, and identified as Bacillus sp. DJ based on its morphology and cellular fatty acid composition. The total extracellular fibrinase (EF) from Bacillus sp. DJ was analyzed using three fibrin zymographic techniques, SDS-fibrin zymography (SDS-FZ), isoelectrofocucing-fibrin zymographs(IEF-FZ), and a two-dimensional SDS-fibrin zymographic analysis (2D SDS-FZ). As a result, the EP map of Bacillus sp. DJ was established. The results suggest that the 2D SDS-FZ method will be a useful tool for the proteomic approach for many other bacterial pretenses.

• Journal of Korea Foundry Society
• /
• v.15 no.4
• /
• pp.408-415
• /
• 1995

Polycrystalline Al-Cu ribbons were produced by planar flow casting(PFC). Solidification behavior and microstructual changes of the ribbons have been investigated as a function of ribbon thickness and processing parameters. The solidification front velocity, V varies within the ribbon, decreasing with increasing the distance, S from the wheel-contact surface, as $V=17.6S^{-1}$. In Al-4.5wt%Cu alloy, rapid decrease in solidification velocity toward the free surface causes a change in solidification morphology from planar to cellular, and finally, to dendritic. The length and inclination of columnar grains solidified with planar front were related to the wheel velocity. The transition from particulate degenerate eutectic structure to regular lamellar eutectic structure was observed to be caused by a difference of the relative growth velocites of ${\alpha}-Al$ and ${\theta}$ during solidification in the Al-Cu eutectic alloy.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.10
• /
• pp.1081-1087
• /
• 2011

An internally radiating photobioreactor was applied for the production of astaxanthin using the unicellular green alga Haematococcus pluvialis. The cellular morphology of H. pluvialis was significantly affected by the intensity of irradiance of the photobioreactor. Small green cells were widespread under lower light intensity, whereas big reddish cells were predominant under high light intensity. For these reasons, growth reflected by cell number or dry weight varied markedly with light conditions. Even under internal illumination of the photobioreactor, light penetration was significantly decreased as algal cells grew. Therefore, we employed a multistage process by gradually increasing the internal illuminations for astaxanthin production. Our results revealed that a multistage process might be essential to the successful operation of a photobioreactor for astaxnthin production using H. pluvialis.

• Animal Systematics, Evolution and Diversity
• /
• v.28 no.3
• /
• pp.212-214
• /
• 2012

The Cymatium Roding, 1798 is a small- to large-sized marine gastropod genus. Three species has been reported thus far for Cymatium in the Korean waters. In general, Cymatium encausticum (Reeve, 1844) is known to occur in tropical seawaters including the Philippine Islands along with its congeners C. gutturnium, C. springsteeni, and C. exile. A single individual of the species was collected from Jejudo Island by SCUBA diving and morphological features were observed using a stereomicroscope. This is the first study to report the occurrence of Cymatium encausticum (Reeve, 1844) from the Korean waters, providing a detailed description of the species with the illustration for the shell morphology.

• BMB Reports
• /
• v.42 no.6
• /
• pp.324-330
• /
• 2009

Autophagy is a bulk lysosomal degradation process important in development, differentiation and cellular homeostasis in multiple organs. Interestingly, neuronal survival is highly dependent on autophagy due to its post-mitotic nature, polarized morphology and active protein trafficking. A growing body of evidence now suggests that alteration or dysfunction of autophagy causes accumulation of abnormal proteins and/or damaged organelles, thereby leading to neurodegenerative disease. Although autophagy generally prevents neuronal cell death, it plays a protective or detrimental role in neurodegenerative disease depending on the environment. In this review, the two sides of autophagy will be discussed in the context of several neurodegenerative diseases.

• BMB Reports
• /
• v.45 no.1
• /
• pp.7-13
• /
• 2012

Phospholipase D (PLD), a superfamily of signaling enzymes that most commonly generate the lipid second messenger Phosphatidic Acid (PA), is found in diverse organisms from bacteria to man and functions in multiple cellular pathways. A fascinating member of the family, MitoPLD, is anchored to the mitochondrial surface and has two reported roles. In the first role, MitoPLD-generated PA regulates mitochondrial shape through facilitating mitochondrial fusion. In the second role, MitoPLD performs a critical function in a pathway that creates a specialized form of RNAi required by developing spermatocytes to suppress transposon mobilization during meiosis. This spermatocyte-specific RNAi, known as piRNA, is generated in the nuage, an electron-dense accumulation of RNA templates and processing proteins that localize adjacent to mitochondria in a structure also called intermitochondrial cement. In this review, we summarize recent findings on these roles for MitoPLD functions, highlighting directions that need to be pursued to define the underlying mechanisms.

• BMB Reports
• /
• v.41 no.1
• /
• pp.11-22
• /
• 2008

Apoptosis (programmed cell death) is a cellular self-destruction mechanism that is essential for a variety of biological events, such as developmental sculpturing, tissue homeostasis, and the removal of unwanted cells. Mitochondria play a crucial role in regulating cell death. $Ca^{2+}$ has long been recognized as a participant in apoptotic pathways. Mitochondria are known to modulate and synchronize $Ca^{2+}$ signaling. Massive accumulation of $Ca^{2+}$ in the mitochondria leads to apoptosis. The $Ca^{2+}$ dynamics of ER and mitochondria appear to be modulated by the Bcl-2 family proteins, key factors involved in apoptosis. The number and morphology of mitochondria are precisely controlled through mitochondrial fusion and fission process by numerous mitochondria-shaping proteins. Mitochondrial fission accompanies apoptotic cell death and appears to be important for progression of the apoptotic pathway. Here, we highlight and discuss the role of mitochondrial calcium handling and mitochondrial fusion and fission machinery in apoptosis.

• Applied Microscopy
• /
• v.19 no.2
• /
• pp.17-26
• /
• 1989

The cells of Campylobacter jejuni treated with physical or chemical disinfection agents were comparatively examined by scanning and transmission electron microscopies for their morphological features and internal ultrastructures. The normal cells of C. jejuni, showed typical spiral rod shapes. The ribosomes, nucleoids, and other cellular constituents were observed to be distributed evenly throughout the cytoplasm. The cells treated with heat or UV-light were changed to spherical or irregular shapes and their cell envelopes were destroyed to form ghost cells by liberating their cytoplasmic components. The cells treated with chlorine or monochloramine were also changed into irregular round shapes. The chlorinated cells showed very rough surface structures with many blob-like protrusions, while the surface of the monochloramine-treated cells appeared to be relatively smooth.

• Biomolecules & Therapeutics
• /
• v.19 no.1
• /
• pp.9-20
• /
• 2011

Repeated administration of addictive drugs causes cellular and molecular changes believed to be the mechanism of pro-addictive behaviors. Neuroadaptations also take place with repeated administration of amphetamine, methylphenidate and atomoxetine, drugs for Attention Deficit Hyperactivity Disorders (ADHD), and it is speculated that these changes may serve as markers to demonstrate the dependence liability of these therapies. In this review, we enumerate the neuroadaptive changes in molecules associated with neuronal signaling and plasticity, as well as neuronal morphology wrought by repeated administration of ADHD medications. We provide the current perspective on the dependence liability of these therapies, and also suggest of some factors that need to be considered in future investigations, so that what is drawn from animal studies would be better consolidated with those known clinically.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.7
• /
• pp.2411-2414
• /
• 2012