• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.271-278
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• 2006

We used polymers of alternating cationic and anionic nature to build up shells on fiber surfaces, strengthen the worn-out fibers and improve paper properties made from such fibers. OCC and ONP pulps were either dipped or salted out in the cationic polyallylamine, polyacrylamide and starch solutions. After centrifugal drying, these were followed by treatments in anionic polyacrylic acid, poly-acrylamide, and starch solutions, respectively. The shell-enhanced fibers were formed into handsheets and their physical properties evaluated. The results show that building multiple shells on worn-out fiber surfaces can strengthen the fibers and paper. The simpler and more practical impregnation-centrifuging treatment provided the desired effects, whereas salting out the polymers produced somewhat superior fibers. The latter process, were impractical, however. The first pair of polymeric shells imparted marked strength improvement, whereas later layers had diminishing efficacies. Overall, the methods can improve fiber quality, attaining paper strength requirements without resorting to expensive measures. Alternate cationic polymer and filler powders were also deposited on fiber surface based on the micriparticle system in an anticipation of stiffness gains. Platy minerals, such as montmorillonite, bentonite, sericite, clay and talc were added following cationic PAM. After dewatering of polymer-pigment shelled fiber of one to 3 pairs of layers, handsheets either calendered or uncalendered were evaluated. The results indicate that regardless of calendaring, stiffness of the handsheets did not improve appreciably while certain other strength properties showed gains. We also attempted the novel starch gel filler addition method wherein tapioca starch and filers (PCC, sericite or clay) were mixed at high solids content of 50% and cooked until gelatinized. The filled handsheets were dried under various conditions and then tested for their properties. Improvements in strengths of modified filled paper were observed.

• Journal of the Korean Wood Science and Technology
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• 제47권4호
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• pp.509-518
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• 2019

This study analyzed the effect of organic solvent extractives on the classification of wood species via near-infrared spectroscopy (NIR). In our previous research, five species of Korean softwood were classified into three groups (i.e., Cryptomeria japonica (cedar)/Chamaecyparis obtuse (cypress), Pinus densiflora (red pine)/Pinus koraiensis (Korean pine), and Larix kaempferi (Larch)) using an NIR-based principal component analysis method. Similar tendencies of extractive distribution were observed among the three groups in that study. Therefore, in this study, we qualitatively analyzed extractives extracted by an organic solvent and analyzed the NIR spectra in terms of the extractives' chemical structure and band assignment to determine their effect in more detail. Cedar/cypress showed a similar NIR spectra patterns by removing the extractives at 1695, 1724, and 2291 nm. D-pinitol, which was detected in cedar, contributed to that wavelength. Red pine/Korean pine showed spectra changes at 1616, 1695, 1681, 1705, 1724, 1731, 1765, 1780, and 2300 nm. Diterpenoids and fatty acid, which have a carboxylic group and an aliphatic double bond, contributed to that wavelength. Larch showed a catechin peak in gas chromatography and mass spectroscopy analysis, but it exhibited very small NIR spectra changes. The aromatic bond in larch seemed to have low sensitivity because of the 1st overtone of the O-H bond of the sawdust cellulose. The three groups sorted via NIR spectroscopy in the previous research showed quite different compositions of extractives, in accordance with the NIR band assignment. Thus, organic solvent extractives are expected to affect the classification of wood species using NIR spectroscopy.

• 한국미생물·생명공학회지
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• 제48권4호
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• pp.539-546
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• 2020

A cellulolytic bacterial strain, S2-3, was isolated from sea water collected in Jeju island, Republic of Korea. The strain was aerobic and gram negative, and formed yellow colored colonies on marine agar medium. S2-3 cells were long rod-shaped, 0.5 × 0.25 ㎛ (width x length) in size, and did not have flagella. The optimal growth conditions for S2-3 were 30-35℃ and pH 6.5-7.0. Analysis of the 16S rRNA gene sequence of S2-3 revealed that it had the highest identity with those of Seonamhaeicola algicola Gy8 (97.08%), Hyunsoonleella udonensis JG48 (95.01%), and Aestuariibaculum scopimerae I-15 (94.86%). In phylogenetic analysis, S2-3 formed the same clade as S. algicola Gy8, implying that S2-3 belongs to the genus Seonamhaeicola. The major fatty acids (>10%) comprised C15:1 iso G (22.29%), C15:0 iso (17.71%), C17:0 iso 3OH (16.06%), and C15:0 iso 3OH (10.7%), resulting in quite different ratio of the component from those of S. algicola Gy8. Moreover, its biochemical characteristics, including acid production and enzyme activities, were different from those of S. algicola Gy8. Therefore, putting all these results together, we concluded S2-3 is distinct species from S. algicola Gy8, and thus named it Seonamhaeicola sp. S2-3. In liquid culture, S2-3 produced extracellular cellulases that can hydrolyze cellulose or cellooligosaccharides into cellobiose, which is a good enzyme resource that deserves further research.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.117-125
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• 2022

Until recently, four types of cellobiose-fermenting Saccharomyces cerevisiae strains have been developed by introduction of a cellobiose metabolic pathway based on either intracellular β-glucosidase (GH1-1) or cellobiose phosphorylase (CBP), along with either an energy-consuming active cellodextrin transporter (CDT-1) or a non-energy-consuming passive cellodextrin facilitator (CDT-2). In this study, the ethanol production performance of two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-2 (N306I) with GH1-1 or CBP were compared with two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-1 (F213L) with GH1-1 or CBP in the simultaneous saccharification and fermentation (SSF) of cellulose under various conditions. It was found that, regardless of the SSF conditions, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the best ethanol production among the four strains. In addition, during SSF contaminated by lactic acid bacteria, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the highest ethanol production and the lowest lactate formation compared with those of other strains, such as the hydrolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-1 with GH1-1, and the glucose-fermenting S. cerevisiae with extracellular β-glucosidase. These results suggest that the cellobiose-fermenting yeast strain exhibiting low energy consumption can enhance the efficiency of the SSF of cellulosic biomass.

• The Plant Pathology Journal
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• 제38권3호
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• pp.212-219
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• 2022

Fusarium root rot caused by the soil-borne fungus Fusarium solani is one of the most important fungal diseases of cassava in Thailand, resulting in high yield losses of more than 80%. This study aimed to investigate if the exogenous application of salicylic acid formulations (Zacha) can induce resistance in cassava against Fusarium root rot and observe the biochemical changes in induced cassava leaf tissues through synchrotron radiation based on Fourier-transform infrared (SR-FTIR) microspectroscopy. We demonstrated that the application of Zacha11 prototype formulations could induce resistance against Fusarium root rot in cassava. The in vitro experimental results showed that Zacha11 prototype formulations inhibited the growth of F. solani at approximately 34.83%. Furthermore, a significant reduction in the disease severity of Fusarium root rot disease at 60 days after challenge inoculation was observed in cassava plants treated with Zacha11 at a concentration of 500 ppm (9.0%). Population densities of F. solani were determined at 7 days after inoculation. Treatment of the Zacha11 at a concentration of 500 ppm resulted in reduced populations compared with the distilled water control and differences among treatment means at each assay date. Moreover, the SR-FTIR spectral changes of Zacha11-treated epidermal tissues of leaves had higher integral areas of lipids, lignins, and pectins (1,770-1,700/cm), amide I (1,700-1,600/cm), amide II (1,600-1,500/cm), hemicellulose, lignin (1,300-1,200/cm), and cellulose (1,155/cm). Therefore, alteration in defensive carbohydrates, lipids, and proteins contributed to generate barriers against Fusarium invasion in cassava roots, leading to lower the root rot disease severity.

• 유기물자원화
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• 제31권1호
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• pp.27-34
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• 2023

본 연구에서는 버섯 폐배지의 혐기성소화 효율 향상을 위해 수열전처리를 실시하고, 리그노셀룰로오스계 물질의 고온 가수분해 과정에서 생성될 수 있는 중간산물이 기질의 생분해도와 바이오가스 전환 효율에 미치는 영향을 함께 판단하였다. 수열전처리 온도의 범위를 150, 180, 210℃로 설정하였으며, 모든 수열전처리 온도에서 기질의 가용화율이 향상되는 결과를 확인할 수 있었다. 추가적으로, 150℃로 버섯 폐배지를 전처리한 경우에는 혐기성소화 효율에 영향을 미칠 수 있는 C/N 비가 개선되는 효과를 함께 확인하였다. 다만 전처리 온도가 180, 210℃인 경우에는 오히려 150℃로 전처리를 수행한 경우에 비해 메탄 생성량이 저하되는 경향을 보였는데, 이는 리그노셀룰로오스 물질의 중간분해 산물인 퓨란유도체의 형성으로 인해 메탄생성균이 영향을 받은 것으로 판단된다. 결국, 수열전처리를 통해 리그노셀룰로오스계 바이오매스의 가용화율 향상을 통한 메탄 생성 향상을 기대할 수 있으나, 혐기성소화 효율을 저해할 수 있는 중간산물이 생성되지 않는 적정 전처리 온도의 확인과 적용이 중요할 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1384-1389
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• 2023

This work aimed to evaluate the feasibility of biohydrogen production from Barley Straw and Miscanthus. The primary obstacle in plant biomass decomposition is the recalcitrance of the biomass itself. Plant cell walls consist of cellulose, hemicellulose, and lignin, which make the plant robust to decomposition. However, the hyperthermophilic bacterium, Caldicellulosiruptor bescii, can efficiently utilize lignocellulosic feedstocks (Barley Straw and Miscanthus) for energy production, and C. bescii can now be metabolically engineered or isolated to produce more hydrogen and other biochemicals. In the present study, two strains, C. bescii JWCB001 (wild-type) and JWCB018 (ΔpyrFA Δldh ΔcbeI), were tested for their ability to increase hydrogen production from Barley Straw and Miscanthus. The JWCB018 resulted in a redirection of carbon and electron (carried by NADH) flow from lactate production to acetate and hydrogen production. JWCB018 produced ~54% and 63% more acetate and hydrogen from Barley Straw, respectively than its wild-type counterpart, JWCB001. Also, 25% more hydrogen from Miscanthus was obtained by the JWCB018 strain with 33% more acetate relative to JWCB001. It was supported that the engineered C. bescii, such as the JWCB018, can be a parental strain to get more hydrogen and other biochemicals from various biomass.

• 한국식품영양과학회지
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• 제36권11호
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• pp.1391-1398
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• 2007

본 연구는 다시마의 활성성분을 열수추출하고, 그 추출물을 제 2형 당뇨병 환자에게 섭취시킴으로서 그들의 혈당, 혈중지질 및 항산화 체계 개선에 있어서 다시마추출물의 효능을 과학적으로 규명하고자 하였다. 다시마를 열수추출하고 동결건조한 후 캡슐화하여 1.4 g을 350 mg씩 4캡슐로 나누어, 아침과 저녁 식후에 2캡슐씩 제 2형 당뇨환자에게 12주간 섭취 시켰다. 위약군은 동량의 cellulose를 실험군과 동일하게 제조한 후 같은 방법으로 섭취하게 하였고 이중맹검법을 사용하였다. 섭취 전후 일반사항 및 식이섭취조사, 신체계측을 실시하였고, 혈액을 채취하여 혈당, 당화혈색소, 혈청지질, 지질과산화물 및 항산화 효소의 변화와 독성검사인 간 및 신장 기능의 변화를 측정하였다. 최종 연구는 총 37명으로 실험군 17명, 대조군 20명으로 양군간의 baseline 특성은 유의적 차이가 없었다. 다시마추출물 섭취군에서 공복혈당은 12주간 섭취 후 $156.0{\pm}15.2mg/dL$에서 $155.8{\pm}14.2mg/dL$로 나타났고, 당화혈색소 역시 $6.74{\pm}0.66%$에서 $6.65{\pm}0.64%$으로 유의적으로 감소하지 않았다. 다시마추출물의 섭취가 12주간 이루어지면서 총콜레스테롤은 $177.0{\pm}16.5mg/dL$에서 $168.6{\pm}15.0mg/dL$로 유의적 (p<0.05)으로 감소한 반면에, 위약군의 경우 $175.8{\pm}17.4mg/dL$에서 $179.8{\pm}19.9$로 변화되었다. 또한 다시마추출물 섭취군의 LDL-콜레스테롤, 중성지방의 변화에서도 섭취 전에 비해 섭취 후 유의적 (p<0.05) 감소를 나타내었으며, 특히 LDL-콜레스테롤의 농도를 고농도군, 정상군, 저농도군으로 분류시 LDL-콜레스테롤 농도가 높은 환자일수록 감소의 폭이 큼을 알 수 있었다. 지질과산물 농도의 변화를 보면 다시마추출물 섭취군은 $1.58{\pm}0.88nmol$에서 $1.13{\pm}0.03nmol$로 유의적(p<0.05)으로 감소되었고, GSH-px활성도 위약군에 비해 다시마추출물 섭취군은 $13.98{\pm}0.66I.U/mg$ protein에서 $14.58{\pm}0.22I.U/mg$ protein로 활성도가 약간 상승하였다. SOD 활성은 실험군($1.18{\pm}0.22$ vs. $1.28{\pm}0.18unit/mg$ protein)에서 유의적(p<0.05)으로 증가하였으며, 간 및 신장 기능 검사에서도 실험 전후 모든 군이 정상범위를 나타내었다. 따라서 본 연구는 당뇨병 환자들의 혈청지질 및 혈액 항산화 효소계에 도움을 줄 수 있는 안전한 보조제로서 다시마추출물의 사용 가능성을 제시하였다.

• 한국식품과학회지
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• 제17권2호
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• pp.121-127
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• 1985

Ciguatoxin 구조 연구의 일환으로 파랑비늘돔 중에 서 독성분을 추출하였는데 Scarus sordidus만 근육과 내장에 독이 있었으나, S.frenatus, S.scaber and S.pectorlis에는 모두 독이 없었다. 실리스산컬럼에서 얻은 조독을 DEAE-셀루로즈 컬럼상에서 콜로로포름, 클로로포름-메타놀 (1 : 1) 및 메타놀로 전개하였더니 클로로포름 유출액(ST-1) 과 클로로포름-메타놀(1 : 1) 유출액에서 독성분이 발견되었고, 메타놀 유출액에서는 독성분이 검출되지 않았다. ST-1과 ST-2을 silica gel 60F-254에 spot하여 클로로포름-메타놀-물-식초산 (90 : 9.5 : 0.2 : 0.3)으로 전개하였더니, 그Rf값이 각각 0.60-0.75, 0.30-0.54였다. DEAE-셀루로즈 컬럼에서 얻은 ST-1을 재재크로마토그라피 하여도 역시 ST-1과 ST-2로 나누어졌다. 이렇게 얻은 ST-1과 ST-2는 세파텍스 LH-20에 흡착시켜, 클로로포름-메타놀(1 : 1) 용매로 전개할 때, 머무름시간이 모두 같았고, 역상 LiChrosorb RP-18를 이용한 HPLC상에서도 머무름시간이 동일하였다. 또 순수한 $ST-1\;(1.10\;{\mu}g)$ 그리고 이것을 1 N NaOH로 처리한 것 $(1.13\;{\mu}g)$을 활성도V인 알루미나 컬럼에 흡착시켜 클로로포름-메타놀 혼합액으로 전개하였더니 알카리처리를 하지 않는 경우는 $0.35\;{\mu}g)$가 클로로포름-메타놀의 9 : 1, 1 : 1 유출액에서, $(0.55\;{\mu}g)$가 메타놀-물 (1 : 1) 유출액에서 검출되었으나, 알카리처리를 한 경우는 처음 독성의 50%가 소실되어, 클로로포름-메타놀 (9 : 1) 유출액에서 $(0.21\;{\mu}g)$, 메타놀-물 (1 : 1) 유출액에서 $(0.80\;{\mu}g)$ 검출되었다. 하면 morey eel내장에서 얻은 독물질도 DEAE-셀루로즈에서 ST-1 과 ST-2로 나누어지며, 이 ST-1의 TLC, HPLC 및 알루미나 컬럼상의 거동이 파랑비늘돔에서 얻은 ST-1의 그것과 같으므로 scaritoxin으로 보고한 ST-1은 ciguatoxin의 형태인 less polar cigutoxin (LPCTX) 으로 생각된다.

• Journal of Korean Neurosurgical Society
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• 제30권6호
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• pp.755-760
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• 2001

Objective : To determine the feasibility of translabyrinthine approach in the vestibular schwannoma patients, the authors reviewed eighteen consecutive cases, focusing at their functional outcome and operative complications. Materials and Method : To evaluate the functional outcome, we reviewed preoperative radiological findings such as size of tumors and location of jugular bulb as well as the preoperative neurological status including audiometric analysis and cranial nerve function in 18 patients, diagnosed as vestibular schwannoma. Also the surgical outcome was evaluated according to the functional preservation of facial nerve and incidence of the surgical complication as well as the extent of surgical resection. Results : The age of patients ranged from 21 to 62 years, with a mean of 50 years. Of 18 patients operated in our center by the translabyrinthine approach, wide exposure with total removal of the mass was possible in 16 cases (88.8%). The facial nerve was anatomically preserved in 88.8%. At six-month follow-up, facial nerve function was good(Grade I-II) in 15 patients(83%) and acceptable(I-IV) in all patients. Although the jugular bulb was highly placed is five patients, gross total resection was possible without facial nerve injury in all patients by the translabyrinthine approach. One patient experienced CSF leakage after surgery, but there was no patient with disabling deficit. Conclusion : Use of the translabyrinthine approach for removal of vestibular schwannomas resulted in good anatomical and functional preservation of the facial nerve, with minimal incidence of morbidity and no mortality. In cases of high jugular bulb impacted into mastoid bone, total removal was possible by displacing the jugular bulb with Surgicel cellulose and placement of bone wax.