• 한국균학회지
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• 제43권4호
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• pp.239-246
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• 2015

참나무와 소나무 목재에서 분리한 Gyrodontium sacchari 균주에 대한 균학적 특성과 목질계 섬유소 분해력을 검정하였다. 균주는 참나무와 소나무 목재에서 분리하였으며 배지는 potato dextrose agar (PDA)에서 가장 생장이 좋았고 생장온도는 참나무에서 분리한 NAAS02335 균주는 $25^{\circ}C$에서, 소나무 목재에서 분리한 NAAS05299 균주는 $30^{\circ}C$에서 가장 우수한 생장을 보였다. 섬유소 분해 효소인 cellulase와 xylanase, amylase의 활성은 G. sacchari NAAS05299 균주가 6.7~12.8배 더 높았으며 리그닌 분해 효소는 G. sacchari NAAS02335 균주가 3.7~138.5배 활성이 더 높았으며 목질계 섬유소를 탄소원으로 첨가하였을 때 효소의 활성은 월등히 증가하였다. 목질계 바이오매스 분해력을 검정한 결과 G. sacchari NAAS05299 균주는 filter paper를 4주만에 완전히 분해하였고 볏짚과 미송, 참나무를 분해하였으나 G. sacchari NAAS02335 균주는 볏짚에서만 분해력을 나타내어 G. sacchari NAAS05299 균주가 더 우수한 바이오매스 분해 효과를 나타내었다.

• 한국미생물·생명공학회지
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• 제16권4호
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• pp.275-281
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• 1988

호알칼리성 Bacillus sp. F204와 Bacillus sp. K 17간에 원형질체 융합에 의한 cellulase와 xylanase를 동시에 생산하는 균주를 개발하기 위하여 두 균주에 500 $\mu\textrm{g}$/ml NTG를 처리한 후 약제내성변이주 인 S20(Km$^r$, Cm$^r$과 G70(Str$^r$)을 분리하였다. 원형질체 형성율은 균체를 대수증식기 중기까지 배양하여 200$\mu\textrm{g}$/m1 Iysozyme으로 37$^{\circ}C$에서 30-45분간 처리하였을 때 약 95%였다. 재생배지에 0.4-0.5M sodium succinate, 0.5% casamino acid, 1.5% polvinylpyrrolidone, 25mM MgC1$_2$및 50mM CaC1$_2$를 첨가하므로 Bacillus sp. F204와 Bacillus sp. K17의 재생율은 각각 24.9%, 26.2%였다. 50mM $Ca^{++}$을 첨가한 30%의 PEG 6,000용액을 45$^{\circ}C$에서 5분간 융합시킴으로써 6.2$\times$$10^{-6}$ 빈도로 융합주를 얻었다. cellulase, xylanase 및 avicelase를 생산하는 융합주는 모균주와 비교하였다.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1322-1329
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• 2011

Filamentous fungi colonizing rice straw were collected from 11 different sites in Korea and were identified based on characterization of their morphology and molecular properties. The fungi were divided into 25 species belonging to 16 genera, including 14 ascomycetes, one zygomycete, and one basidiomycete. Fungal cellulolytic and xylanolytic enzymes were assessed through a two-step process, wherein highly active cellulase- and/or hemicellulase-producing fungi were selected in a first screening step followed by a second step to isolate the best enzyme-producer. Twenty-five fungal species were first screened for the production of total cellulase (TC), endo-${\beta}$-1,4 glucanase (EG), and endo-${\beta}$-1,4 xylanase (XYL) using solid-state fermentation with rice straw as substrate. From this screening, six species, namely, Aspergillus niger KUC5183, A. ochraceus KUC5204, A. versicolor KUC5201, Mucor circinelloides KUC6014, Trichoderma harzianum 1 KUC5182, and an unknown basidiomycete species, KUC8721, were selected. These six species were then incubated in liquid Mandels' media containing cellulose, glucose, rice straw, or xylan as the sole carbon source and the activities of six different enzymes were measured. Enzyme production was highly influenced by media conditions and in some cases significantly increased. Through this screening process, Trichoderma harzianum 1 KUC5182 was selected as the best enzyme producer. Rice straw and xylan were good carbon sources for the screening of cellulolytic and xylanolytic enzymes.

• 한국균학회지
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• 제26권1호통권84호
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• pp.127-133
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• 1998

Trichoderma reesei QM 9414를 N-methyl-N'-nitro-N-nitrosoguanidine으로 처리하여 얻은 돌연변이주들을 여러 탄소원에서 배양했을 때 carboxymethylcellulose(CMC), fiter paper 등의 기질에 대한 활성측정결과 다음과 같은 결과를 얻었다. 모균주가 catabolite repression을 받는 반면에 돌연변이주들의 cellulase 활성은 glucose를 탄소원으로 사용한 배지에서 모균주에 비해 CMCase 8.4배, FPase가 $5.4{\sim}5.7$배 증가함으로써 glucose-derepression성질을 갖는 돌연변이주들을 얻었으며 glucose를 탄소원으로 사용하고 lactose로 효소의 생산을 유도시켜본 결과 모균주에 비해 효소의 생산에 안정성을 갖는 것으로 나타났으며 돌연변이주 1이 상대적으로 더 우수한 돌연변이주로 나타났다. 돌연변이주들에 의해 생산된 효소는 모균주와 마찬가지로 pH 4.8, $60^{\circ}C$에서 최적활성을 나타내었다.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.125-131
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• 2019

We have isolated and identified 72 bacterial strains from four bentonite samples collected at the mining areas located in Gyeongsangbuk-do, Republic of Korea, and measured their hydrolytic enzyme (${\alpha}$-amylase, protease, and cellulase) activities to identify the isolates with industrial-use potential. Most of the isolates belonged to the Bacillaceae, with minor portions being from the Paenibacillaceae, Micrococcaceae, and Bacillales Family XII at the family level. Of the strains isolated, 33 had extracellular ${\alpha}$-amylase activity, 30 strains produced cellulase, and 35 strains produced protease. Strain MBLB1268, having the highest ${\alpha}$-amylase activity, was identified as Bacillus siamensis ($0.38{\pm}0.06U/ml$). Bacillus tequilensis MBLB1223, isolated from Byi33-b, showed the highest cellulase activity ($0.26{\pm} 0.04U/ml$), whereas Bacillus wiedmannii MBLB1197, isolated from Zdb130-b, exhibited the highest protease activity ($54.99{\pm}0.78U/ml$). These findings show that diverse bacteria of the Bacillaceae family adhere to and exist in bentonite and are potential sources of industrially useful hydrolytic enzymes.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.529-532
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• 2001

Korean food waste, one of the abundantly available but environmentally problematic organic wastes in Korea, was utilized as solid-substrate by fungal strain Aspergillus niger ATcC 6275 for the production of enzymemixture containing amylase, cellulase and xylanase. The enzyme mixture can be used as high value-added animal feed. Solid-state fermentation method yielded a 84-fold enhancement in xylanase activity compared with submerged fermentation method. The effect of incubation period, incubation temperature, pH of medium, moisture content, inoculum size and enrichment of the medium with nitrogen and carbon sources were observed for optimal production of these enzymes The optimal amylase activity of 33.10 U/g, cellulase activity of 24.41 U/g, xylanase activity of 328.84 U/g were obtained at 8 days incubation with 50%(w/w) soy bean flake, with incubation temperature of $25^{\circ}C$, pH of 6.38, optimal moisture content of 55% and with inoculum size of $3.8{\times}10^6$spore/g. Enzyme activities were enhanced when ImM $CaSO_4$, 2% Malt extract and 2% galactose were added as mineral, nitrogen and carbon enrichment respectively.

• 원예과학기술지
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• 제19권4호
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• pp.545-549
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• 2001

에틸렌의 수용체와의 결합을 방해함으로써 에틸렌의 작용을 방해하는 물질은 1-MCP의 처리를 통하여 단감 과실의 과육 연화에 대한 에틸렌의 영향을 밝히기 위한 실험을 수행하였다. 1-MCP와 에틸렌의 처리에 따른 경도 변화의 양상은 cellulase, PG, PME, ${\beta}$-galactosidase 등의 세포벽 분해 효소의 활성 변화 양상과 유사하였으며, 이들 효소의 활성은 1-MCP의 처리에 의해 저하되었다. 이러한 결과는 에틸렌의 영향에 의한 각종 세포벽 분해 효소의 활성화가 저장 후 단감 과실의 과육 연화 현상과 밀접한 관련이 있음을 보인다. 그러나 연화 지연 효과와는 달리 저장 후의 단감 과실에서 1-MCP는 에틸렌의 생성, 즉 ACC의 축적 및 ACC oxidase 활성을 억제하지 못하였으며, 이러한 사실은 저장 후 단감 과실에 있어서 과육의 연화 현상이 과실의 에틸렌 생성량 그 자체보다는 과실의 에틸렌에 대한 반응성에 보다 밀접하게 관련되어 있음을 보인다.

• 미생물학회지
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• 제47권2호
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• pp.130-136
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• 2011

러시아의 바이칼에 존재하는 고유종인 Baikalospongia과 Lubomirskia의 sponge로부터 방선균을 분리하였다. 분리된 방선균은 16S rRNA gene 분석 결과, Streptomyces griseoplanus, S. halstedii, S. violascens, S. flavovirens, S. microflavus에 각각 속하였다. 이 방선균들은 온도, 탄소이용, enzyme 활성, fatty acid 조성 등의 실험 결과에서, 각각 서로 다른 특징을 나타냈었다. 분리된 방선균의 배양온도는 30-37, pH는 8-9, 염분농도는 0-1.5에서 가장 잘 자라는 것으로 확인되었다. 주요 cellular fatty acid는 anteiso-$C_{15:0}$, iso-$C_{15:0}$ and iso-$C_{16:0}$로 나타났다. 특히 ATS-BA-19는 DNase와 chitinase 활성을 나타내었고, ATS-BA-16는 cellulase와 protease 활성을 나타내는 것으로 확인되었다. 또 두개의 분리된 방선균에서 그람음성 균주인 Pseudomonas aeruginosa에서 생장을 저해함을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제24권10호
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• pp.1427-1437
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• 2014

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, ${\beta}$-glucosidase, xylanase, and ${\beta}$-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of ${\beta}$-glucosidase and core hemicellulases (xylanase and ${\beta}$-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external ${\beta}$-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.374-379
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• 2003

Four rumen fistulated Murrah buffaloes were used to study the effect of four diets differing in roughage to concentrate ratio on rumen biochemical changes, microbial enzyme profile and in sacco degradability of feed in a $4{\times}4$ Latin Square design. The animals were fed four diets consisting of 80:20, 70:30, 60:40 and 50:50 ratios of wheat straw and concentrate mixtures, respectively. Wheat straw and concentrate mixture were mixed with water (0.6 l/kg feed) and complete feed mixture was offered to the animals at 8:00 h and 16:00 h in two equal parts. The variation in pH of rumen liquor (difference of maximum and minimum during 0-8 h post feeding) increased with increasing level of concentrate mixture in the diet. There was no effect of diet composition on volatile fatty acids, total nitrogen and trichloro-acetic acid precipitable nitrogen in the rumen liquor, but ammonia nitrogen increased with increasing level of concentrate mixture in the ration. Major portions of all fibre degrading enzymes were present in the particulate material (PM) of the rumen contents, but protease was absent in PM fraction. The activities of micro-crystalline cellulase, acetyl esterase and protease increased with increase in the level of concentrate mixture, but the activities of other enzymes (carboxymethylcellulase, filter paper degrading activity, xylanase, $\beta$-glucosidase and $\beta$-xylosidase) were not affected. The in sacco degradability and effective degradability of feeds increased with increasing level of concentrate mixture in the ration.