• 한국미생물·생명공학회지
• /
• 제22권3호
• /
• pp.233-239
• /
• 1994

The characteristics of the bacteriophage resistant Lactococcus lactis subsp. cremoris ATCC 11602-A1, the phage-resistant mutant of Lactococcus lactis subsp. cremoris ATCC 11602, was examined. Electron microscopic study of phage adsorption to A1 revealed that after 10 min. incubation of the host-phage mixture, A1 did not show phage adsorption, and after 60 min. did not show a real burst and the release of new phage particles which could be detected in the mixture of its parent strain and phage. However, the phage adsorption rate of A1 after SDS treatment increased to 98%. Moreover, when the cell walls from A1 and parent strain, and the polysaccharide(PS) and peptidoglycan(PG) of their cell wall were mixed with phage and incubated for 15 min., PS and PG from A1 did not bind phage, but only SD-treated cell wall bound phage, and the cell wall and PS of parent strain bound phage. Both A1 and parent strain treated with 0.2 N HCl-and 5% TCA(100$$C) did not bind phage. The results suggest that the phage receptor is still present in the cell wall of the A1, but a cell wall constituent hydrolyzed by SDS blocks phage adsorption by masking the phage receptor. It also suggests that the phage receptor of parent strain is associated with PS of the cell wall.

• Journal of Plant Biology
• /
• 제34권2호
• /
• pp.129-136
• /
• 1991

기주식물 (토끼풀, Trifolium repens L.)의 유조직에 침입하여 생장하는 실새삼(Cuscuta australis R. Brown)의 흡기세포들의 미세구조를 조사하였다. 기주세포들과 직접 접촉되어 있는 흡기의 정면부위는 아직 분지되지 않은 선단세포들 및 이들로부터 분지하여 신장된 세포들(hyphae)로 구성되었다. 이 두 유형의 세포들은 전자밀도가 높은 세포질을 지니며, 또한 핵막이 심하게 만입된 커다란 핵을 갖는 특징을 보였다. 어떤 선단세포에서는 비후된 세포벽 물질이 기주세포벽의 중엽(middle lamellae)으로 침입하고, 파괴된 기주세포의 잔유물을 내포하는 양상을 보였다. 두 유형의 세포들은 원형질막과 세포벽이 안쪽으로 돌출하는 구조를 갖는데, 이는 기주세포들로부터 물질흡수를 촉진하기 위한 표면적의 증가현상으로 해석된다. 기주와 흡기세포의 세포벽사이를 통과하는 원형질연락사는 관찰되지 않았다. 두 식물세포의 경계면에서는 융합된 세포벽을 관찰할 수 있는데, 이 구조는 기주로부터 흡기로의 수분 및 영양물질의 수송 경로로써 작용할 수 있을 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
• /
• 제34권3호
• /
• pp.8-14
• /
• 2006

목재의 탄화기구를 이해하기 위하여 굴참나무재를 사용하여 $250{\sim}740^{\circ}C$의 온도조건에서 탄화하였다. 탄화온도가 높아질수록 시험체의 부피는 수축하였고, 방사 방향으로 할렬이 발생하였다. 탄화온도가 증가함에 따라 목탄의 중량감소율은 증가되었으며, 특히 탄화온도 $300{\sim}340^{\circ}C$에서 급격히 증가하는 경향이 나타났다. 목재의 도관은 탄화 시 방사방향보다 접선방향으로 매우 크게 수축하였다. 탄화온도 $250{\sim}300^{\circ}C$의 경우, 목섬유나 도관 주위의 유세포들이 탄화되지 않은 세포벽 형태를 보여주었다. 그러나 탄화온도 $340^{\circ}C$이상에서는 세포벽층이 매끄러운 비결정형인 목탄의 형태가 관찰되기 시작하였다. 탄화온도 $300^{\circ}C$까지는 목재 셀룰로오스의 결정성이 남아있었으나 $340^{\circ}C$ 이상에서는 비결정성으로 변화되고 있는 것이 관찰되었다.

• Journal of the Korean Wood Science and Technology
• /
• 제15권3호
• /
• pp.34-43
• /
• 1987

This study was performed to find out the types of linkage of carbohydrates in wood cell walls. To study the structure of linkage of carbohydrates in wood cell walls, we have attempted to find out the method holocellulose preparation and optimum condition of enzyme hydrolysis in holocellulose, and fractionate oligosaccharide with products that hydrolized partly by acetolysis and deacetylation in holocellulose. We have achieved four results. These results as follow; 1. At first. we reacted in wood meal $NaClO_2$ 1g per lignin lg for one hour and then the same of quantity $NaClO_2$ for four hours. Through these experiments, we have developed new holocellulose preparation method which had low loss of carbohydrates and high effect of the delignification. 2. The optimum condition of enzyme hydrolysis of holocellulose which had lignin was 0.005M sodium acetate buffer (pH 5.0). We have achieved 7.2% reducing sugar through the procedure that reactioned 0.01g holocellulose putting enzyme 0.03g for 72 hours. It may be supposed that 5.5% of lignin contained in holocellulose prevented enzyme contaction from holocellulose and so this lignin has resulted in the low efficiency of enzyme hydrolysis. 3. We did not fractionated from oligosaccharides which were preparated by the method of acetolysis and deacetylation in holocellulose. The reason is that holocellulose having a lot of lignin prevented prefectly partial hydrolysis from the method of acetolysis and deacetylation. 4. We attempted analysis of six standard substances through HPLC apparatus having sugar pak 1 column which we have changed flow rate and the column temperature variably. These six standard substances were D-glucose, D-mannose, D-xylose, D-galactose and L-rhamnose, L-arabinose, But sugar pak 1 column was not fitted analysis of four substances because D-galactose, D-mannose, D-xylose, L-rhamnose were agreement with elution time. And so, we could not analize four standard substances with sugar pak 1 column.

• 펄프종이기술
• /
• 제42권1호
• /
• pp.7-12
• /
• 2010

Morphological characteristics of hemp fiber were investigated using a light microscope in order to provide fundamental data for the use of hemp as a papermaking law material. Phloem of hemp is composed of cortical parenchyma cells and bast fiber with thick walls while xylem is composed of vessel, wood fiber and ray parenchyma cells. Also there are solitary pore and radial pore multiple which exist in diffuse porous pattern. Ray cells consist of uniseriate rays and thin walled ray parenchyma cells. Wood fibers are composed of three types: a large diameter fiber with longer length; a large diameter fiber with shorter length; a small diameter fiber with medium length. Vessel elements are composed of: a medium length one; a longer length one; the one whose both end walls have ligules or tails. Parenchyma cells in xylem and pit parenchyma cells have completely different size and shape. For bast fiber, the average length is about 4.4 mm and the width is about $30.5\;{\mu}m$; for vessel element, $600.0\;{\mu}m$ in length and $493.6\;{\mu}m$ in width; for wood fiber, $1000\;{\mu}m$ and $38.9\;{\mu}m$; for parenchyma cell, $50\;{\mu}m$ and $26.4\;{\mu}m$.

• 한국식품과학회지
• /
• 제24권5호
• /
• pp.477-481
• /
• 1992

품질이 좋은 된장을 제조하기 위한 연구의 일환으로 재래식 된장과 Aspergillus oryzae와 Bacillus natto를 혼합한 된장을 제조해서 발효기간에 따른 대두조직의 변화를 조사한 결과 가압, 가열처리에 의하여 세포벽이 붕괴되거나 ghost 상태를 보였고 표피부와 내부의 세포질은 원형질 분리가 현저한 차이가 있으며 protease에 의한 당단백 구상체의 융합과 amylase에 의하여 전분이 분해되어 작은 공포를 보였으며 발효에 의한 균침투 과정이 시일이 경과함에 따라 표피부에서 내부로 이행되어지며 Aspergillus oryzae와 Bacillus natto 혼합 된장의 표피부와 유세포에서 점질물이 보인다. 또한 발효시간이 경과함에 따라 염색성이 나빠지고 세포벽이 다각형으로 되는데 재래식 보다는 Aspergillus oryzae와 Bacillus natto 혼합구가 현저하였다.

• Journal of the Korean Wood Science and Technology
• /
• 제51권1호
• /
• pp.1-13
• /
• 2023

Sengon (Falcataria moluccana Miq.) tree offers a wood of low quality and durability owing to its low density and thin cell walls. This study aimed to improve the properties of sengon wood by making the wood magnetic, producing new functions, and characterizing magnetic sengon wood. Each wood sample was treated using one of the following impregnation solutions: Untreated, 7.5% nano magnetite-furfuryl alcohol (Fe₃O₄-FA), 10% nano Fe₃O₄-FA, and 12.5% nano Fe₃O₄-FA. The impregnation process began with vacuum treatment at 0.5 bar for 2 h, followed by applying a pressure of 1 bar for 2 h. The samples were then tested for dimensional stability and density and characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) analysis, and vibrating sample magnetometry (VSM) analysis. The results showed that the Fe₃O₄-FA impregnation treatment considerable affected the dimensional stability, measured in terms of weight percent gain, anti-swelling efficiency, water uptake, and bulking effect, as well as the density of sengon wood. Changes in wood morphology were detected by the presence of Fe deposits in the cell walls and cell cavities of the wood using SEM-EDX analysis. XRD and FTIR analyses showed the appearance of magnetite peaks in the diffractogram and Fe-O functional groups. Based on the VSM analysis, treated sengon wood is classified as a superparamagnetic material with soft magnetic properties. Overall, 10% Fe₃O₄-FA treatment led to the highest increase in dimensional stability and density of sengon wood.

• 한국식품영양과학회지
• /
• 제14권4호
• /
• pp.401-408
• /
• 1985

효모세포벽 용해효소의 일종인 Zymolyase$(endo-{\beta}-1\;,3-glucanase)$와 더불어 Arthrobacter luteus로 부터 생산되었고, 또한 Zymolyase의 조효소중에서 발견된 바 있는 염기성 AL-protease의 효모세포벽 용해작용을 S. sake의 생세포와 그 세포벽 표품(標品)을 사용하여 조사하였다. AL-protease의 효모 생세포에 대한 용해활성은 그 단독작용만으로는 지극히 미약하였으나, Zymolyase와의 복합작용에 의해서 용해활성은 고도로 상승하였다. 효모생세포를 AL-protease와 Zymolyase로써 단계적인 처리를 할 경우, 효모세포는 AL-protease로 전처리된 뒤에 Zymolyase로 처리되는 처리 순서에 한하여 효과적으로 용해되었다. 이러한 AL-protease의 촉진적 작용은 AL-protease처럼 염기성이고 serine protease로 알려진 몇가지 시판의 효소들 중에서는 발견되지 않았으며, 또한 AL-protease의 이러한 작용은 실험에 사용된 효모들의 배양조건 및 균종에 따라서 커다란 영향을 받는 것으로 밝혀졌다. AL-protease는 효모세포벽 표품(標品)으로부터 일정량의 peptide와 상당량의 당을 유리시키고 있으나, 그 세포벽을 66% 이상은 용해시키지 못하였다. 반면에, Zymolyase는 그 단독작용으로도 효모세포벽을 거의 완전히 용해시킬 수 있었다. 이상의 실험결과를 기초로 하여, S. sake 세포벽의 용해에 있어서 AL-protease의 효소적 작용은, 먼저 AL-protease가 mannan과 단백질로 구성되는 세포벽 표층부에 결합하고, 이어서 그들의 구조를 변화시킴으로써, Zymolyase를 세포벽의 외부로 부터 알카리 불용성 glucan으로 구축되고 있는 세포벽 내부의 골격구조로까지의 침투를 촉진시키는 것으로 추론되었다.

• International Journal of Advanced Culture Technology
• /
• 제8권1호
• /
• pp.182-187
• /
• 2020

Silver nanoparticles (AgNPs) have been manufactured in recent years and widely used in various fields. Reactive oxygen species (ROS), which occur in AgNPs, destroy cell membranes. It is widely accepted that ROS generated in this manner inhibit microorganisms growth and causes toxic effects, However, it does not affect cell membranes directly but positively affects growth in plants with cell walls. The nanoball used in this experiment is a new material that generates ROS stably and is used in aqueous solution. Results of this study indicate a 30% increase in yield of Ginseng mixed with culture soil. The analysis of soil condition after cultivation showed that the possibility of repetitive cultivation in soil mixed with Nanoball was high. This suggests that Nanoball is an antimicrobial active material due to the microbial / extermination effect of pathogenic microorganisms. Therefore, there may be potential applications in agricultural cultivation sites as a repetitive cultivation technology that reuses soil.

• Journal of the Korean Wood Science and Technology
• /
• 제35권2호
• /
• pp.9-15
• /
• 2007

A comparative study of the structure and organization of the primary and secondary walls in different types of tropical plant waste fibers was carried out using transmission electron microscopy (TEM). The thickness of each layer was also measured using Image Analyzer. TEM micrographs haveconfirmed that cell wall structure of all six types of tropical plant waste fibers (empty fruit bunch, oil palm frond, oil palm trunk, coir, banana stem and pineapple leaf) has the same ultrastructure with wood fibre. The fibers consisted of middle lamella, primary and thick secondary wall with different thickness for different types of fibers. The secondary wall was differentiated into a $S_1$ layer, a unique multi-lamellae $S_2$ layer, and $S_3$ layer.