• Journal of Microbiology and Biotechnology
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• 제10권4호
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• pp.522-528
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• 2000

A total of about 300 fungal isolates from forest havitats were screened for inhibitors of tobacco mosaic virus (TMV) infection using its local lesion host, Nicotiana tabacum cv. Xanthi nc. Ine of the isolates, 14T, showed a strong activity against TMV infection, and was identified as an Apiocrea sp. based on its morphological characterstics. Rice was an optimum culture medium for its fermentation, and two antiviral compounds, KGT 141 and KGT 142, were resolved from the rice culture through column chromatography, TLC, and HPLC. By NMR and FAB-MS, the two compounds were identified as chrysospermins B (KGT 141) and D (KGT 142), both of which are peptaibols with 19-mer amino acids possessing an acetylated N-terminus and a hydroxy-amino acid (tryptophanol) at the C-terminus. Both compounds showed inhibitory activities against TMV infection, but chrysospermin D showed the stronger activity than chrysospermin B. The former of $100{\;}\mu\textrm{g}/ml$ and 54.7% at $10{\;}\mu\textrm{g}/ml$, respectively. Furthermore, the chrysospermins were highly cytotoxic toward cancer cell lines of PC-3 (prostrate) and K562 (leukemia), and inhibited growth of the Gram-positive bacteria tested, especially the plant pathogenic bacterium Corynebacterium lilium. To the best of our knowledge, this is the first report on the inhibition of plant virus infection by antimicrobial peptaibols.

• Archives of Reconstructive Microsurgery
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• 제4권1호
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• pp.9-15
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• 1995

Free vascularized composite tissue transfer is more frequently underwent for reconstruction of complicated tissue defects with the recent advance of microsurgery. But postoperative result was not satifactory because of donor site morbidity, flap bulkiness and cosmetic problem. So would no longer be a problem if we can obtain the exact donor tissue required for the recipient site as allotransplantation and designing the flap. Allotransplantation has been resolved with the recent development of immunosuppressive agents, while reconstruction has made great progress with the refinement of microsurgical techniques in the last 20 years. The final sucess or failure of the operative procedure in transplantation is so utterly dependent no the availability of strategies that can control the immune system effectively, selectively, safely to allow allotransplantation of a nonvital body part. 1 used 2 strains of rats, BUF and LEW, for the limb allotransplantation as a composite tissue transfer. The primary goal of this program is to improve results in clinical transplantation by accelerating the transformation of new immunological knowledge into useful medicine. Two of the most promising new immunosuppressive compounds are FK-t06(FK) and rapamycin(RPM). Both drugs are antibiotic macrolide fungal fermentation products that presumably suppress the immune system in ways similar to cyclosporin(CyA). This study shows that two new immunosuppressive drugs compare the immunosuppressive activity and effectiveness of FK-506 and RPM for prevention of the limb allograft rejection in the rat. Additional experiments investigate the dose, route of administration and histologic findings. These data demonstrates that rapamycin is far more potent and effective than FK-506 when both compounds are administered by the intraperitoneal route, as well as prolonged graft survival significantly in a dose-route dependent manner. These results lead to the view that vascularized allograft composite tissue transfer can become a reality with the expectation of possible future application in reconstructive surgery of humans.

• Asian-Australasian Journal of Animal Sciences
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• 제6권1호
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• pp.67-72
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• 1993

Three sheep fitted with cannulas in the rumen and the caecum were used in a $3{\times}3$ Latin square design to study the changes in ruminal and caecal microbial populations and their metabolite composition with ammoniated rice straw feeding. The 3 diets contained either 80% untreated rice straw (UTS) or ammoniated rice straw (ATS) and 20% formula feed. These were a control diet (C), a urea supplemented diet (U) containing urea at 1.1% and an ammoniated rice straw diet (AT). Data were analyzed by analysis of variance and means separated by the Student Neumann Kuel's multiple comparison. AT feeding increased ruminal bacterial counts, in particular cellulolytic bacterial counts (p < 0.05) which were 1.8, 2.4 and 7.0 (${\times}10^6/ml$ ruminal fluid) for C, U and AT, respectively. There was an increasing tendency (p < 0.10) in ruminal fungal population with U; values were 2.0, 5.2, 3.1 (${\times}10^3/ml$ ruminal fluid) for C, U and AT, respectively. Ruminal protozoa counts were not significantly (p > 0.05) altered with diets. Caecal total viable bacterial count with AT was about thrice the value with C. Total VFA concentration in the rumen was significantly increased (p < 0.025) (7.7 mmol/dl for C and 8.2 mmol/dl for AT) and correspondingly, pH lowered when AT was fed. Sheep on AT tended to produce less acetate and more butyrate in the rumen without significance (p > 0.05). Similar to the rumen, total VFA concentrations of 4.4, 3.8 and 5.2 mmol/dl were detected, respectively, for C, U and AT. Caecal ammonia-nitrogen concentrations were about six-fold of that in the rumen, though there were no differences (p > 0.05) among treatments.

• Journal of the Korean Wood Science and Technology
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• 제29권4호
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• pp.60-66
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• 2001

아세틸화 목재를 부후균에 노출시켜 laccase의 생성을 액체배양기와 고체배양기상에서 검토하고 $^{13}C$-CP/MAS NMR 분석을 통하여 목재 내 화학성분의 변화와 치환 도입된 아세틸기의 변화를 검토하여 보았다. 액체배양기상에서 laccase의 활성은 glucose를 탄소원으로 할 때 보다 높게 나타났으며, 고체배양기상에서는 laccase 의 활성이 원활히 이루어지지 않았다. $^{13}C$-CP/MAS NMR의 분석 결과 리그닌 뿐만 아니라 셀룰로오스부분에서도 아세틸화가 이루어 졌음을 알 수 있었다. 부후된 아세틸화 목재의 분석 결과, 아세틸기의 목재내 결합이 목재 부후균 T. versicolor에 대해서 안정적이었다.

• Journal of Microbiology
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• 제44권2호
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• pp.233-242
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• 2006

The objectives of this study were to optimize submerged culture conditions of a new fungal isolate, Ganorderma resinaceum, and to enhance the production of bioactive mycelial biomass and exopolysaccharides (EPS) by fed-batch culture. The maximum mycelial growth and EPS production in batch culture were achieved in a medium containing 10 g/l glucose, 8 g/l soy peptone, and 5 mM $MnCl_2$ at an initial pH 6.0 and temperature $31^{\circ}C$. After optimization of culture medium and environmental conditions in batch cultures, a fed-batch culture strategy was employed to enhance production of mycelial biomass and EPS. Five different EPS with molecular weights ranging from 53,000 to 5,257,000 g/mole were obtained from either top or bottom fractions of ethanol precipitate of culture filtrate. A fed-batch culture of G. resinaceum led to enhanced production of both mycelial biomass and EPS. The maximum concentrations of mycelial biomass (42.2 g/l) and EPS (4.6 g/l) were obtained when 50 g/l of glucose was fed at day 6 into an initial 10 g/l of glucose medium. It may be worth attempting with other mushroom fermentation processes for enhanced production of mushroom polysaccharides, particularly those with industrial potential.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.947-953
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• 2011

A fungal strain, Aspergillus terreus strain GA2, isolated from an agricultural field cultivating sweet sorghum, produced feruloyl esterase using maize bran. In order to obtain maximum yields of feruloyl esterase, the solid state fermentation (SSF) conditions for enzyme production were standardized. Effective feruloyl esterase production was observed with maize bran as substrate followed by wheat bran, coconut husk, and rice husk among the tested agro-waste crop residues. Optimum particle size of 0.71-0.3 mm and moisture content of 80% favored enzyme production. Moreover, optimum feruloyl esterase production was observed at pH 6.0 and a temperature of $30^{\circ}C$. Supplementation of potato starch (0.6%) as the carbon source and casein (1%) as the nitrogen source favored enzyme production. Furthermore, the culture produced the enzyme after 7 days of incubation when the C:N ratio was 5. Optimization of the SSF conditions revealed that maximum enzyme activity (1,162 U/gds) was observed after 7 days in a production medium of 80% moisture content and pH 6.0 containing 16 g maize bran [25% (w/v)] of particle size of 0.71-0.3 mm, 0.6% potato starch, 3.0% casein, and 64 ml of formulated basal salt solution. Overall, the enzyme production was enhanced by 3.2-fold as compared with un-optimized conditions.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.306-315
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• 2017

Metabolic engineering with a high-yielding mutant, A. terreus AN37, was performed to enhance the production of itaconic acid (IA). Reportedly, the gene cluster for IA biosynthesis is composed of four genes: reg (regulator), mtt (mitochondrial transporter), cad (cis-aconitate decarboxylase), and mfs (membrane transporter). By overexpressing each gene of the IA gene cluster in A. terreus AN37 transformed by the restriction enzyme-mediated integration method, several transformants showing high productivity of IA were successfully obtained. One of the AN37/cad transformants could produce a very high amount of IA (75 g/l) in shake-flask cultivations, showing an average of 5% higher IA titer compared with the high-yielding control strain. Notably, in the case of the mfs transformants, a maximal increase of 18.3% in IA production was observed relative to the control strain under the identical fermentation conditions. Meanwhile, the overexpression of reg and mtt genes showed no significant improvements in IA production. In summary, the overexpressed cis-aconitate decarboxylase (CAD) and putative membrane transporter (MFS) appeared to have positive influences on the enhanced IA productivity of the respective transformant. The maximal increases of 13.6~18.3% in IA productivity of the transformed strains should be noted, since the parallel mother strain used in this study is indeed a very high-performance mutant that has been obtained through intensive rational screening programs in our laboratory.

• KSBB Journal
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• 제13권2호
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• pp.214-219
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• 1998

Polymerase chain reaction(PCR) was conducted to obtain the gene encoding glucose oxidase(GOD) from Aspergillus niger(ATCC 2110) and the DNA sequence determined was coincided with published GOD sequence from A. niger. Recombinant transforming vector containing GOD and hygromycin B(hyg.B) resistant gene(hph) was constructed and used for further transformation of A. niger ATCC 2110. Selectivity of hyg.B against A. niger differed depending on which media were used i.e., nutrient-rich media such as potato dextrose agar(PDA) and complete medium(CM) showed only 50% growth inhibition at 400 $\mu$m ml$^-1$ of hyg.B while the minimal media inhibited mycelial growth completely at 200 $\mu$m ml$^-1$ of hyg.B. Twenty to sixty putative transformants were isolated from the hyg.B-containing minimal top agar, transferred successively onto alternating selective and nonselective media for a mitotic stability of hyg.B resistance and, then, single-spored. Among the stable transformants, the transformant(GOD1-6) grown by flask culture showed the considerable increase of extracellular GOD activity, which was estimated to the degree of 50% - 100% comparing to that of wild type. Transformation of tGOD1-6 was resulted from integration of the vectors into heterologous as well as homologous regions of the A. niger genome. Southern blot analysis revealed that there were two independent integrations of vector into fungal genome and one into the GOD gene due to homologous recombination. In addition, GOD activity and sodium gluconate production when tGOD1-6 was fed-batch fermented were enhanced 11 fold and 2.25 fold, respectively, compared to that of the wild type.

• Mycobiology
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• 제41권2호
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• pp.100-107
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• 2013

Diverse fungi are present in Korean traditional meju and they are known to play an important role in fermented soybean products. To determine the origin of the fungi in meju, we examined the mycoflora of soybeans from 10 traditional meju factories. The samples were untreated or treated with sodium hypochlorite, and placed on malt extract agar (MEA), dichloran 18% glycerol agar (DG18), and dichloran rose bengal chloramphenicol agar (DRBC) medium. A total of 794 fungal strains were isolated and they were identified as 41 genera and 86 species. From sodium hypochlorite untreated soybeans, the genera, Cladosporium (55%), Eurotium (51%), Fusarium (33%), Penicillium (22%), and Aspergillus (exclusion of Eurotium) (20%), were mainly isolated, and Eurotium herbariorum (22%), Eurotium repens (18%), Cladosporium tenuissimum (18%), F. fujikuroi (18%), Aspergillus oryzae/flavus (7%), and Penicillium steckii (6%) were the predominant species. In case of sodium hypochloritetreated soybeans, Eurotium (31%) and Cladosporium (5%) were frequently isolated, but Aspergillus (excluding Eurotium), Penicillium and Fusarium which were frequently isolated from untreated soybeans, were rarely isolated. Eurotium herbariorum (21%), Eurotium repens (8%), and Cladosporium tenuissimum (3%) were the predominant species. Of the 41 genera and 86 species isolated from soybeans, 13 genera and 33 species were also found in meju. These results suggest that the fungi on soybeans may influence the mycoflora of meju.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 춘계학술대회
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• pp.113.2-114
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• 1979

$\beta-Galactosidase$ is an enzyme which catalizes hydrolysis of lactose, a natural substrate, to glucose and galctose and transferring some monosac-charide units to active acceptors as sugar or alcohol. The occurence of $\beta-Galactosidase$ is known in various microorganisms, animals and higher plants and has been studied by many investigatigators. Especially, a great deal of articles for the enzyme of E. coli have been presented in genetic control mechanism and induction-repression effects of proteins, On the other hand, in the dairly products industry, it is important to hydrolyes lactosd which is the principal sugar of milk and milk products. During the last few years, the interest in enzymatic hydrolysis of milk lactose has teen increased, because of the lactose intolerence in large groups of the population. Microbial $\beta-Galactosidases$ are considered potentially most suitable for processing milk to hydrolyse lactose and, in recent years, the immobilized enzyme from yeast has been examined. Howev, most of the microbial $\beta-Gal$ actosidase are intracellular enzymes, except a few fungal $\beta-Gala-$ ctosidases, and extracellular $\beta-Galactosidase$ which may be favorable to industrial applieation is not so well investigated. On this studies, a mold producing a potent extracellular $\beta-Galactosidase$ was isolated from soil and identified as an imperfect fungus, Beauveria bassians. In this strain, both extracellular and intracellular $\beta-Galactosidases$ were produced simultaneously and a great increase of the extracellular production was acheved by improving the cultural conditions. The extracellular enzyme was purified more than 1, 000 times by procedures including Phosphocellulose and Sephadex G-200 chromatographies. Several characteristics of the enzymewas clarified with this preparation. The enzyme has a main subunit of molecular weight of 80, 000 which makes an active aggregate. And at neutral pH range, it has optimum pH for activity and stability. The Km value was determined to be 0.45$\times$10$^{-3}$ M for $o-Nitrophenyl-\beta-Galactoside.$ In any event, it is interesting to sttudy the $\beta-Galactosidase$ of B. bassiana for the mechanism of secretion and conformational structure of enzyme.