• Applied Biological Chemistry
• /
• 제48권4호
• /
• pp.345-351
• /
• 2005

난배양 미생물로부터 천연물질을 찾기 위하여 토양으로부터 직접분리 된 DNA와 cosmid vector를 이용하여 metagenomic library를 제작하고 탐색 하였다. 대장균에서 발현되는 유전자은행 초기 탐색 결과 LB배지에서 잘 자라면서 브라운 색깔을 내는 여러 개의 clone을 선발 하였다. 선발된 여러 후보 clone중 pYS85C는 돌연변이를 유도하였으며 색깔을 생산하지않는 clone 들에 대하여 염기서열을 결정 하였다. 돌연변이clone들로부터 결정된 pYS85C 염기서열 결과 아미노산이 393개이며 44.5 kDa으로 색소형성에 관여하는 4-hydroxyphenylpyruvic acid dioxygenase(HPPD) 유전자로 판명 되었다. 또한, BLAST비교 분석에서 이효소는 기존에 밝혀진 HPPD효소와 60% 정도의 identity를 보였고 C-말단에서는 많은 conserved domain이 있었다. 이러한 결과로 볼 때 천연물질을 합성 할 수 있는 유전자는 토양DNA로부터 직접 분리되어 발현될 수 있으며 이러한 기술은 새로운 물질을 찾는데 중요한 tool이 될 수 있다.

• 보존과학연구
• /
• 통권36호
• /
• pp.11-32
• /
• 2015

문화재 수리, 복원재료 및 회화용으로 사용되는 천연광물성 무기안료인 석청의 물리적 특성을 연구하였다. 본 연구를 위해 시중에서 유통되고 있는 청색계열의 안료(KA-한국, JA, JB, JC-일본, CA, CB, CC-중국)를 선정하였다. 연구에 앞서 XRD, XRF분석을 통하여 안료의 결정구조 및 조성을 확인하였으며, 본 연구에 사용된 안료는 Azurite가 주원료임이 확인되었다. 조성물을 확인한 안료는 입도, 색도, 비중, 흡유량 등 물리적 특성을 평가하였으며, 입도에 따른 물리적 특성의 변화를 확인하였다. 안료는 입도가 작아짐에 따라 명도는 커지고, 청색도는 커지다가 다시 작아지는 특성이 있으며, KA가 안료번호에 따라 가장 잘 분급되어 있음을 알 수 있었다. 비중은 입자크기가 커질수록 커지고, 흡유량은 입자크기가 작아질수록 커졌다. 이러한 결과를 토대로 안료의 기초적인 물리적 특성을 규명하고 나아가 문화재 수리, 복원에 선택적으로 사용하는데 도움이 될 것으로 기대한다.

• 한국작물학회지
• /
• 제53권4호
• /
• pp.407-412
• /
• 2008

검정콩 안토시아닌의 항산화력과 암세포독성을 분석한 결과는 다음과 같다. 1. 안토시아닌 함량은 일품검정콩이 공시재료 중 가장 높게 나타났으며, 특히 C3G 함량은 타 계통보다 2배 이상 높았다. 2. 안토시아닌을 분획한 후 각각의 pigment로 항산화 효과를 분석한 결과 TEAC 법과 DPPH법 모두 C3G, D3G, 및 Pt3G의 효과가 인정되었으며, C3G와 D3G의 항산화력이 높게 나타났다. 일품검정콩과 재래속청간 품종 비교에서는 일품검정콩이 3가지 분획 모두 재래속청 보다 항산화 효과가 높았으며, 이는 TEAC 법과 DPPH법 공히 같은 경향이었다. 3. 인간 암세포인 Jurkat T 세포와 MCF-7 세포에 안토시 아닌 개별색소(C3G, D3G 및 Pt3G)를 $100{\sim}500\;{\mu}g/mL$ 농도로 처리하고 암세포에 대한 독성을 관찰한 결과, 3가지 시험물질 모두 두 가지 암 세포에서 세포독성 효과를 나타내었다. 이와 같은 결과는 검정콩 안토시아닌이 여러 가지 생리활성 효과를 가지고 있음을 나타내는 결과로 판단된다.

• Nutrition Research and Practice
• /
• 제2권1호
• /
• pp.46-49
• /
• 2008

Anthocyanin pigments from varieties of black, red and wild rice were identified and quantified to evaluate their potential as nutritional function, natural colorants or functional food ingredients. Anthocyanin extraction was conducted with acidified methanol with 0.1M HCl (85:15, v/v) and identification of anthocyanin, aglycone and sugar moieties was conducted by comparison with purified standards by HPLC, Ultraviolet-Visible absorption spectrophotometer and paper chromatography. Black and wild rice showed three different types of pigments by HPLC whereas red rice variety did not show any anthocyanins. Out of three pigments detected, one (peak 2) was characterized as cyanidin-3-glucoside (C3G) by comparison of spectroscopic and chromatographic properties with an authentic standard, and another (peak 3) was tentatively identified as cyanidin-fructoside on the basis of spectroscopic properties with ${\lambda}_{max}$ of aglycone in 1% HCl methanol at 537 nm, electrospray ionization mass spectra with major ions at 449 and 287 m/z and chromatographic properties. But another pigment (peak 1) has not been characterized. The most abundant anthocyanin in black and wild rice was C3G.

• Journal of Microbiology and Biotechnology
• /
• 제12권2호
• /
• pp.204-208
• /
• 2002

A Streptomyces sp. isolated from a soil sample collected in Taejeon, Korea has previously been found to produce two new polyene antibiotics. The two new antibiotics were named "16-methyloxazolomycin (antibacterial)" and "tetrin C (antifungal)", and their chemical structures are presented elsewhere [10, 11]. In the current study, chemotaxonomy, numerical taxonomy, and ISP methods were all employed for the taxonomic study. The spore chains were spirales and the spore surface was smooth. The spore mass was a gray series and no melanin pigment was produced. On the basis of the morphological and physiological properties, the microorganism was identified to be Streptomyces erumpens, belonging to the gray series of category IV, as defined by Bergey′s Manual. Tetrin C at the concentration of 20 ${\mu}g$/ml demonstrated a potent in vivo (pot test) preventive effect against rice blast, rice sheath blight, cucumber gray mold, wheat powdery mildew, and barley leaf rust.

• Preventive Nutrition and Food Science
• /
• 제10권3호
• /
• pp.244-250
• /
• 2005

The copper-containing enzyme, tyrosinase, catalyzes the oxidation of tyrosine into dihydroxy phenylalanine (DOPA) and subsequently DOPAquinone. It is responsible, not only for the pigment melanin biosynthesis in human skin, but also for browning in foods. In the present study, tyrosinase inhibitory and antioxidant activities of Korean mistletoe extract and its fractions were investigated. As a result, both water and methanol (MeOn) extracts inhibited the tyrosinase activity. Among the fractions, the fraction eluted with $95\%$ MeOn significantly inhibited the tyrosinase activity. The fraction was further purified, and the purified fraction C strongly inhibited the enzyme activity up to $92\%$. In addition, water and methanol extracts exerted radical scavenging effects. The fractions eluted with $70\%\;MeOn\;and\;95\%$ Me on showed high radical scavenging activities. In conclusion, these results suggest that Korean mistletoe extract and its fractions might be useful for the treatment of various dermatological disorders such as epidermal hyperpigmentation and for improving food quality.

• Journal of Microbiology and Biotechnology
• /
• 제5권4호
• /
• pp.200-205
• /
• 1995

Nutritional factors regulating the morphological differentiation and physiological differentiation of Streptomyces exfoliatus SMF13 on surface cultures were evaluated. S. exfoliatus SMF13 produced leupeptin and chymotrypsin-like protease (CTP) at the stage of substrate mycelium growth, and leupeptin-inactivating enzyme (LIE) and trypsin-like protease (TLP) at the stage of aerial mycelium growth. The activity of leupeptin and CTP was high in the region of active growing substrate mycelium, whereas the activity of LIE and TLP was high in the region of aerial mycelium or spores. The differentiations were induced in glucose-limited conditions or by the addition of glucose anti-metabolite (methyl $\alpha$-glucopyranoside), but repressed by high concentrations of glucose or casamino acids. Morphological differentiation (formation of aerial mycelia and spores) was closely related with physiological differentiation (formation of brown-pigment, LIE and TLP). The local distribution of leupeptin, CTP, LIE, and TLP in a developing colony showed that colony development correlated with the production and functions of the compounds: CTP is essential for providing a nitrogen source for mycelium growth: leupeptin regulates TLP activity: LIE inactivates leupeptin: TLP hydrolyzes nongrowing mycelium.

• Journal of Microbiology and Biotechnology
• /
• 제29권4호
• /
• pp.507-517
• /
• 2019

Rhodotorula is a group of pigment-producing yeasts well known for its intracellular biosynthesis of carotenoids such as ${\beta}-carotene$, ${\gamma}-carotene$, torulene and torularhodin. The great potential of carotenoids in applications in food and feed as well as in health products and cosmetics has generated a market value expected to reach over $2.0 billion by 2022. Due to growing public concern over food safety, the demand for natural carotenoids is rising, and this trend significantly encourages the use of microbial fermentation for natural carotenoid production. This review covers the biological properties of carotenoids and the most recent findings on the carotenoid biosynthetic pathway, as well as strategies for the metabolic engineering methods for the enhancement of carotenoid production by Rhodotorula. The practical approaches to improving carotenoid yields, which have been facilitated by advancements in strain work as well as the optimization of media and fermentation conditions, were summarized respectively.

• Journal of Microbiology and Biotechnology
• /
• 제29권9호
• /
• pp.1453-1459
• /
• 2019

Zeaxanthin is an important pigment in the photo-protection mechanism of microalgae. However, zeaxanthin epoxidase, an enzyme involved in the accumulation and conversion of zeaxanthin, has not been extensively studied in microalgae. In this work, we report the expression pattern of zeaxanthin epoxidase in Dunaliella tertiolecta (DtZEP) at different light and diverse salinity conditions. To confirm the responsiveness to light conditions, the ZEP expression pattern was investigated in photoperiodic (16 h of light and 8 h of dark) and continuous (24 h of light and 0 h of dark) light conditions. mRNA expression levels in photoperiodic conditions fluctuated along with the light/dark cycle, whereas those in continuous light remained unchanged. In varying salinity conditions, the highest mRNA and protein levels were detected in cells cultured in 1.5 M NaCl, and ZEP expression levels in cells shifted from 0.6 M NaCl to 1.5 M NaCl increased gradually. These results show that mRNA expression of DtZEP responds rapidly to the light/dark cycle or increased salinity, whereas changes in protein synthesis do not occur within a short period. Taken together, we show that DtZEP gene expression responds rapidly to light irradiation and hyperosmotic stress. In addition, ZEP expression patterns in light or salinity conditions are similar to those of higher plants, even though the habitat of D. tertiolecta is different.

• Journal of Plant Biotechnology
• /
• 제48권2호
• /
• pp.100-105
• /
• 2021

Genetic engineering is a potential approach to improve secondary metabolism in plants. In order to elucidate the effect of production of anthocyanin pigment 1 (PAP1) overexpression on the bioactivity of ginseng, we analyzed its antioxidant, antimicrobial, and anti-elastase activities in this study. Our results showed that PAP1 overexpression increased the production of polyphenolic compounds including anthocyanins. The antioxidant, antimicrobial, and anti-elastase activities were stronger in anthocyanin-overproducing ginseng hairy roots (AOX) than in wild ginseng hairy roots. Using a different solvent system (0, 30, 70, and 100% (v/v) EtOH), we revealed that variations in the contents of the polyphenolic compounds were highly correlated with changes in the antioxidant and antimicrobial activities of AOX. The antioxidant, antimicrobial, and anti-elastase effects of AOX highlight genetic engineering as a powerful approach to enhance the therapeutic properties of plants. Our results show that AOX could potentially have various functional applications in the cosmetic and pharmaceutical industries.