• Journal of Mushroom
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• v.16 no.1
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• pp.9-15
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• 2018

This study aimed to characterize the mycelial morphologies of Hericium erinaceus isolates, including 18 wild-type collections and cultivatable species 'Noru 1' and 'Noru 2', in Korea. The morphological characteristics were used to classify the species based on aerial or branched mycelia and their brownish or whitish colors when grown on potato dextrose agar. Of the wild-type collections, the isolates KFRI 509, KFRI 1091, KFRI 1093, and KFRI 1623 showed faster mycelial growth than the cultivars 'Noru 1' and 'Noru 2'. Moreover, 60% ethanol extracts of the fruiting body of the mushroom showed the highest phenol content and DPPH and ABTS radical scavenging activity. The DPPH and ABTS radical scavenging activities of KFRI 507, KFRI 508, KFRI 842, and KFRI 1623 were 10-60% higher than those of 'Noru 1' and 'Noru 2', depending on the extract concentrations. Thus, results suggest that these wild-type collections could be useful for breeding genetic sources or processed food materials with high antioxidant activity.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.1-9
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• 2006

Biodevices composed of biomolecular layer by mimicking the natural functions of cells and the interaction mechanisms of the constituted biomolecules have been developed in various industrial fields such as medical diagnosis, drug screening, electronic device, bioprocess, and environmental pollution detection. To construct biodevices such as bioelectronic devices (biomolecular diode, bio-information storage device and bioelectroluminescence device), protein chip, DNA chip, and cell chip, biomolecules including DNA, protein, and cells have been used. Fusion technology consisting of immobilization technology of biomolecules, micro/nano-scale patterning, detection technology, and MEMs technology has been used to construct the biodevices. Recently, nanotechnology has been applied to construct nano-biodevices. In this paper, the current technology status of biodevice including its fabrication technology and applications is described and the future development direction is proposed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.177-181
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• 2006

In this study, phytochemicals from the wold and cultivated Lithospermum erythrorhizon (gromwell), which has been used for medicinal purpose or natural coloring material from the old days, were extracted by methanol and fractionated with hexane. The shikonin compounds in the fraction was isolated and their chemical structures were identified by $^1H$ and $^{13}C-NMR$. It was found that compound I was the shikonin substance with molecular weight of 288.3 and chemical formula of $C_{16}H_{16}O_5$, and compound II being deoxyshikonin substance with molecular weight of 272.3 and chemical formula of $C_{16}H_{16}O_4$. The Quantities of these compounds in the wild and cultivated gromwells was determined.

• Research in Plant Disease
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• v.8 no.2
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• pp.107-112
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• 2002

This study was carried out to identify the causal pathogens and investigated the characteristics of Penicillium spp. isolated from postharvest decay of pear. One hundred and ninety eight Penicillium spp. were isolated from infected pear fruits. The lesions were formed when the isolated pathogen were inoculated into the wounds and unwounds of pear fruit. Total isolates were classified into 15 groups by the size, color, pigment of colony and shape of conidia. These isolates were identified to be P.expansum, P.solitum, and P.crustosum according to the types of morphological, cultural and physiological characteristics. The pathogenicity was higher in wound inoculation at low temperature than unwound one. This result confirmed that wound promoted the disease appearance. P.expansum was appeared to have the most strong virulence, whereas P.solitum and P.crustosum were classified as weak virulent species by pathogenicity test on pear fruits.

• The Korean Journal of Mycology
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• v.15 no.4
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• pp.217-223
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• 1987

Mitochondria in the L. edodes was purified by linear sucrose density gradient centrifugation. The mitochondrial ATPase activity was investigated by various wavelength illumination for 30 min at dark state. The mitochondrial ATPase activity was stimulated 1.6 fold by 680 nm illumination compared with dark control group. The mitochondrial ATPase activity of different light illumination time at 680 nm was stimulated 2.3 fold at 5 minutes compared with dark control group. Its optimum pH and temperature were found to be 7.5 and $59^{\circ}C$ after illumination for 5 minutes at 680 nm. The mitochondrial ATPase activity was activated by 5 mmol $Fe^{3+}$, 0.1 mmol $Fe^{2+}$, 0.1 mmol $Mg^{2+}$, 0.5 mmol $K^{+}$, and 0.1 mmol $Ca^{2+}$ ion. But, the enzyme was inhibited by 5 mmol $Na^{+}$ ion.

• The Korean Journal of Mycology
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• v.15 no.4
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• pp.224-230
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• 1987

Effects Of organic compound, photosensitizer and $K^+$ ion influx. On the light-induced ATPase of mitochondria in L. edodes purified by linear sucrose density gradient centrifugation were studied. The mitochondrial ATPase activity was investigated by various wavelength illumination at dark state. The mitochondrial ATPase was activated 139% and 128% by 10m mol dithiothreitol and 0.1m mol quinacrine, respectively. This enzyme also was activated 36% by 0.1m mol phenazine methosulfate as photosensitizer. But, 100 mg oligomycin and 1m mol phlorizin inhibited activity of enzyme to 48% and 45%, respectively. Its optimum wavelength was 690 nm on the effect of $K^+$ ion influx, its optimum pH and temperature were found to be 7.2 and $55^{\circ}C$.

• The Korean Journal of Mycology
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• v.17 no.2
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• pp.99-104
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• 1989

Effects of organic compounds, photosensitizers and influx of metal ions on the light-induced mitochondrial ATP synthase in Lentinus edodes purified by stepped sucrose density gradient centrifugation were studied. In our previous work, the activation wavelength and the illumination time of mitochondrial ATP synthase were 470 nm and 15 sec, respectively. This enzyme was activated 85% by 1 mmole 2,6-dichlorophenol indopheol and inhibited by 1 mmole 2,-4-dinitrophenol, $10\;{\mu}mole$ 2-heptyl-4-hydroxyquinoline-N-oxide and $100\;{\mu}g$ oligomycin per ml of ethanol. Particularly, the enzyme was activated 414% by 10 mmole phenazine methosulfate as photosensitizer at 470 nm light. In the influx effects of $Fe^{3+}$ and $Fe^{2+}$ ion, the activity of the above enzyme increased under the optimal light condition compared with nonillumination state.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.131-140
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• 2015

To set up unicellular cyanobacterial strains with photo-biological $H_2$ production potential, live samples were repeatedly collected from 68 stations in the coastal zone of Korea for the four years since 2005. Among 77 cyanobacterial strains established six (KNU strains, CB-MAL002, 026, 031, 054, 055 and 058) were finally chosen as the excellent strains for $H_2$ production with $H_2$ accumulation over 0.15 mL $H_2\;mL^{-1}$ under general basic $H_2$ production conditions as well as positive $H_2$ production for more than 60 hr. To explore optimum procedures for higher $H_2$ production efficiency of the six cyanobacterial strains, the inter-strain differences in the growth rate under the gradients of water temperature and salinity were investigated. The maximum daily growth rates of the six strains ranged from 1.78 to 2.08, and all of them exhibited $N_2-fixation$ ability. Based on the similarity of the 16S rRNA sequences, all the test strains were quite close to Cyanothece sp. ATCC51142 (99%). The six strains, however, were grouped into separate clades from strain ATCC51142 in the molecular phylogeny diagram. Chlorophyll- a content was 3.4~7.8% of the total dried weight, and the phycoerythrin and phycocyanin contents were half of those in the Atlantic strain, Synechococcus sp. Miami BG03511. The growth of the six strains was significantly suppressed at temperatures above the optimal range, $30{\sim}35^{\circ}C$, to be nearly stopped at $40^{\circ}C$. The growth was not inhibited by high salinities of 30 psu salinity in all the strains while strain CB055 maintained its high growth rate at low salinities down to 15 psu. The euryhaline strains like CB055 might support massive biotechnological cultivation systems using natural basal seawater in temperate latitudes. base seawater. The biological and ecophysiological characteristics of the test strains may contribute to designing the optimal procedures for photo-biological $H_2$ production by unicellular cyanobacteria.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.607-616
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• 2013

Light with two faces, beneficial and harmful effects is an important signal for every living cell. Optimal adaptation to light environment enhances the fitness of an organism and survival in nature. Understandings of light quality and plant growth provide with the economical guides for artificial light sources like LEDs. Compared with those under white light, the 1 week seedlings of Chinese cabbage (Brassica rapa) under monochromic red and blue light showed normal development and growth. In contrast to extremely long and etiolated hypocotyls of the seedlings under dark, those under far-red etiolated were extremely short. Based on the microarray analysis, blue light induced the vigorous development and growth and two fold changes of transcripts than red light condition. To have insight of gene products under different light qualities conditions, GO term enrichments were calculated and each gene according to their GO terms were categorized. The blue and red lights affected the expressions of genes related to biological process. Especially, the genes related to metabolic process and developmental process and plastid and chloroplast in the cellular component category were induced under blue light. This study provided the molecular biological evidence for various light qualities on the growing process of B. rapa.

• Journal of Life Science
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• v.31 no.8
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• pp.719-728
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• 2021

Melanin pigments are abundantly distributed in mammalian skin, hair, eyes, and nervous system. Under normal physiological conditions, melanin protects the skin against various environmental stresses and acts as a physiological redox buffer to maintain homeostasis. However, abnormal melanin accumulation results in various hyperpigmentation conditions, such as chloasma, freckles, senile lentigo, and inflammatory pigmentation. Tyrosinase, a copper-containing enzyme, plays an important role in the regulation of the melanin pigment biosynthetic pathway. Although several whitening agents based on tyrosinase inhibition have been developed, their side effects, such as allergies, DNA damage, mutagenesis, and cytotoxicity of melanocytes, limit their applications. In this study, we synthesized 4-chromanone derivatives (MHY compounds) and investigated their ability to inhibit tyrosinase activity. Of these compounds, (E)-3-(4-hydroxybenzylidene)chroman-4-one (MHY1294) more potently inhibited the enzymatic activity of tyrosinase (IC₅₀ = 5.1±0.86 μM) than kojic acid (14.3±1.43 μM), a representative tyrosinase inhibitor. In addition, MHY1294 showed competitive inhibitory action at the catalytic site of tyrosinase and had greater binding affinity at this site than kojic acid. Furthermore, MHY1294 effectively inhibited α-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis and intracellular tyrosinase activity in B16F10 melanoma cells. The results of the present study indicate that MHY1294 may be considered as a candidate pharmacological agent and cosmetic whitening ingredient.