• Journal of the Korean Wood Science and Technology
• /
• 제21권1호
• /
• pp.39-50
• /
• 1993

The purpose of this study was to describe the micromorphological changes in Korean red pine (Pinus densiflora S. et Z.) wood decayed by a major brown-rot fungus, Lentinus lepideus, using scanning electron microscope and transmission electron microscope. At the end of the 12-week exposure to the fungus in soil block procedure(ASTM 1971), test blocks sustained 5.02% weight loss. The formation of bore hole by hyphae and penetration of hyphae through bordered pit were not observed. Instead, fungal hyphae appeared to penetrate axially tracheid luminar from the the ray cells via cross field pits. Hyphae were mainly found in lignin rich cell corner regions of tracheids, and also extensive degradation of tracheid wall occurred in this region. Extensive degradation of $S_2$ layer occurred without noticeable alteration of the $S_3$ layer, but warty layer and compound middle lamella remained relatively intact. Localized erosion, the characteristic of white rot, was observed in some cell wall and wall components including lignin were found to be decomposed.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2005년도 추계 학술발표회
• /
• pp.15-20
• /
• 2005

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by analytical electron microscopy and atomic force microscopy. A blast-susceptible cultivar, Jinmi, and partially resistant cultivars, Hwaseong and Suwon345, were grown under a hydroponic culture system with modified Yoshida's nutrient solution. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamella, and Intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface with relatively small deposition on stomatal guard cells in silicon-treated plants. Force-distance curve measurements revealed relative hardness and smaller adhesion force in silicon-treated plants (18.65 uN) than control plants (28.39 uN). Moreover, force modulation microscopy showed higher mean height values of elastic Images In silicon-treated plants(1.26 V) than in control plants (0.44 V), implying the increased leaf hardness by silicon treatment. These results strongly suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

• ALGAE
• /
• 제31권2호
• /
• pp.117-128
• /
• 2016

Cryptomonas curvata Ehrenberg is a photosynthetic freshwater flagellate and the type species of the genus Cryptomonas. We examined the flagellar apparatus of cryptomorphic C. curvata by transmission electron microscopy. The major components of the flagellar apparatus are the non-keeled rhizostyle (Rhs), striated fibrous root (SR), striated fiber-associated microtubular root (SRm), mitochondrion-associated lamella (ML), and two types of microtubular roots (3r and 2r). The non-keeled Rhs originate at the ventral basal body and consist of two types of microtubule bands extending together into the middle of the cell. The SR and SRm extend parallel to the left side of the cell. The ML originates from the ventral basal body and is a plate-like fibrous structure associated with mitochondria. The 3r extends from the dorsal basal body toward the dorsal anterior of the cell. The 2r originates between the two basal bodies and extends shortly to the left of the cell. The overall configuration of the flagellar apparatus is most similar to that previously reported for C. pyrenoidifera. These results demonstrate that the features of the flagellar apparatus are useful for distinguishing closely related species and inferring phylogenetic relationships among taxa.

• 한국식품과학회지
• /
• 제19권2호
• /
• pp.164-170
• /
• 1987

강남콩과 대두를 삶아 분리한 고물의 미세구조를 광학 현미경 및 SEM으로 조사하고 그 화학조성과 조직감 특성을 비교하였다. 강남콩 고물의 경우 각각의 세포가 잘 분리되었으나 대두 고물은 여러개의 세포가 결학된 덩어리가 많이 포함되어 있었다. SEM 사진에 의하면 강남콩 고물을 구성하는 세포는 구형이었으나 대두 고물의 구성세포는 긴 자루 형태를 가지고 있었다. 펙틴질을 비교적 많이 함유하는 대두 고물의 경우 높은 접착성과 응집성을 나타내었다.

• Journal of the Korean Wood Science and Technology
• /
• 제24권1호
• /
• pp.68-74
• /
• 1996

Present work was undertaken to investigate the origin of milled wood lignin(MWL) in the wood cell wall using immunocytochemical techniques, which can provide the information on the localization of specific antigens(MWL in the present study) to be examined. Spruce MWL dissolved in DMSO and emulsified with Freund adjuvant was injected directly into the mouse spleen. The animals were boostered at two-week intervals after the initial immunization. Blood samples were purified in standard procedures. The characteristics of antibodies against MWL were tested by indirect ELISA. Visualization of MWL was carried out using conventional indirect immunogold-labelling methods on the ultrathin sections of spruce wood. Immuno-TEM observations showed that the immunogold probes were selectively attached to secondary cell walls of spruce wood. The most intense labelling was frequently observed in the S2 layer. In contrast, gold labelling in the lignin-rich regions, such as middle lamella and cell corner was not found. The immuno-TEM provides an indication that spruce MWL originates from the S2 layer.

• Environmental Analysis Health and Toxicology
• /
• 제21권1호
• /
• pp.35-43
• /
• 2006

Reproduction and organ structure of the pale chub, Zacco platypus in Isa stream were investigated by means of histological methods. The results of the study confirmed reproductive abnormality and histopathological features in the pale chub. The gonadosomatic index (GSI) of the fish showed two peak in April and August. In summer season, GSI of the male was about two times of the female's GSI. Monthly variation of the gonadal development was very irregular. From the histological analysis of the organ structure, epidermal atrophy, necrosis and hyperplasia of pigment cell were observed in the skin. Epithelial layer lifting and clubbing of the lamella and bifurcation of the filament were observed in the gill. Also histological changes as congestion, cytoplasmic degeneration of hepatic cell, degeneration of bile duct, glomerular dilatation, degeneration of renal tubule and pycnosis of interstitial cell were identified in the liver and kidney, respectively.

• 한국조리학회지
• /
• 제12권4호
• /
• pp.299-319
• /
• 2006

The purpose of this study was to investigate the changes of hardness and microstructure of Dongchimi cooked with various sources of sugar(xylitol, xylose, sugar, pear juice). It was fermented at $10^{\circ}C$ for 60 days. The changes of pH in Dongchimi used different kinds of sugar decreased in all samples during the fermentation period, and then showed a slow decrease after 12 days of fermentation. The total acidity of Dongchimi using xylitol arrived slowly at the best tasting condition($0.3\sim0.4$ point) compared with other conditions. The changes of salt content were showed high as compared with other test conditions in 0 day, the day of fermentation. At the early stage of fermentation, the changes of turbidity of Dongchimi using sugar, pear juice were showed high as compared with those of Dongchimi using xylitol, xylose for $5\sim15$ days of fermentation. The maximum cutting force of Chinese radish Dongchimi showed the highest value among al at the 25 th day of ripening and then decreased gradually. The maximum cutting force of Dongchimi using sugar showed the lowest. The calcium and magnesium contents of Dongchimi juice and Chinese radish Dongchimi juice using xylitol were observed high at the early stage of fermentation and showed the highest value during the fermentation period. The microstructure showed disintegration appearance of middle lamella and cell wall during the fermentation period.

• 한국자원식물학회지
• /
• 제14권2호
• /
• pp.102-107
• /
• 2001

팽이버섯 1주기를 수확한 폐배지 톱밥을 버섯재배 용으로 재활용 할 수 있는지를 알아보고자 팽이버섯을 재배한 침엽수재 의 톱밥을 현미경적 관찰을 통해 그 분해정도와 분해양태를 파악하였다. 아울러 팽이버섯 재배에 사용된 톱밥의 수종 식별도 실시하였다. 팽이버섯 재배용으로 사용된 톱밥의 수종은 대부분 소나무속 경송류로 식별되었고 극히 일부만 미송 (Douglas-fir)톱밥이 존재하였다. 팽이버섯 1주기를 수확한 폐배지 소나무 톱밥에는 균사에 노출된 부분과 방사조직에서 균사의 밀도가 높게 나타났다. 팽이버섯균의 공격을 받은 세 포벽은 박벽화현상과 침식현상을 보였으나, 이 같은 부후양태를 보인 세포벽은 극히 일부에 지나지 않았다. 이상의 현미경 관찰결과 팽이버섯을 1주기 수확한 소나무 톱밥은 버섯재배용으로 재활용하기에 충분한 세포벽 물질을 보유하고 있는 것으로 나타났다.

• 한국미생물·생명공학회지
• /
• 제29권3호
• /
• pp.176-180
• /
• 2001

PPase 는 식물세포 중엽부는 주성분인 protopectine를 분해하여 maceration(죽화: 단세포화)하는 기능이 있다. PPase는 대부분의 야채류 및 과실류의 단세포화에 응용하여 새로운 식품재료로 이용이 가능하다. 본 연구에서 먼저 PPase 생산을 향상시키기 위해서 배양조건을 조사하였는데, 탄소원으로 glucose는 catabolite repression이 일언자 않는 1%가 적절하였고 pH는 8.0으로 조절할때PPase 생산이 향상되었다. 그리고 산소공급속도는 1.0vvm, 500rpm으로 조절하는것이 회분식 배양에서 PPase의 생산에 효과적이었다. 이 결과로 유가배양을 실시하여 PPase의 생산효율이 flask 배양(5,417 IL $-1/h^{-1}$ )회분식 배양( $72,000UL^{-1}$$ h^{-1}$ )에 비해 각각 15.6배 1.17배의 증가를 보였다. 이와 같은 유가배양을 실시하는것이 PPase의 생산성을 증대시키는 데 효과적이라 할 수 있다.

• 한국미생물·생명공학회지
• /
• 제27권5호
• /
• pp.378-384
• /
• 1999

Protopectinase (PPases) are heterologous group of enzymes that degrade pectin from the insoluble protopection which is constituent of the middle lamella and primary cell wall of higher plants by restricted depolymerization. From the previous report[6], enzymatically separated plant cells, which are produced from plant tissues by PPases treatment, showed well-conserved cellular components with their rigid cell wall and this characteristic is applicable to preparation of novel food material. The purpose of this study is to investigate the effect of medium composition of PPase production from Bacillus subtilis EK11 which was selected as a PPase producer. Various carbon sources and concentrations on PPase production were studied and corn starch at 0.7% was the most effective for production of PPase. Among the nitrogen sources, yeast extract was the most effective for PPase production and the effect of (NH4)2SO4 was notable as inotganic nitrogen source. Inorganic compounds such as KH2PO4, K2HPO4, Na3-citrate.2H2O and MgSO4 were optimized for PPase production. PPase activity was inhibited by the adition of Ba2+ or Zn2+. The optimal medium for PPase production was devised: 0.7% corn starch, 0.3% yeast extract, 1.4% KH2PO4, 0.6% K2HPO4, 0.1% Na3-citrate.2H2O and 0.02% MgSO4. PPase production by using the optimum medium was carried out with shaking cultivation at 37$^{\circ}C$. The maximum PPase activity of 256unit/ml could be obtained after the cultivation for 48hrs. The activity was increased about 2.2timesthan the activity, 112 unit/ml, in basal medium.