• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.497-504
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• 2006

Glycosides are important functional materials in foods. Transformation, especially hydrolysis, of the sugar moieties tends to improve the functional properties of the administered glycosides in vivo. Various probiotic bacteria and edible food-grade fungi such as bifidobacteria, lactobacilli, leuconostocs, yeasts, and aspergilli are potential industrial microorganisms to transform glycosides of ginsenosides from ginseng, platycodin saponins from Platycodon grandiflorum, Trignoella foenum-graecum (TFG) saponins, and isoflavones from soybeans and Puerariae radix, respectively, by fermentation or enzymatic reaction. In this review, various transformation pathways bearing potential significance with respect to the changes in structure and function of the various glycosides from the food materials will be introduced. In conclusion, the proper combination of food microorganisms and transformation conditions will improve the functionality and the sensory value and reduce the cytotoxicity of the functional glycosides present in various functional food raw materials.

• 현장농수산연구지
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• 제9권1호
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• pp.33-46
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• 2007

표고버섯 폐골목을 이용한 식용버섯류 배지를 개발하기 위하여 표고버섯 재배 후 폐기 되거나 혹은 재배과정 중에 오염균에 의해 피해를 입은 폐골목으로 가공한 톱밥을 재료로하여 배지를 제조하고 이 배지에 느타리버섯, 큰느타리버섯, 잎새버삿 그리고 팽이버섯 균주를 공시하여 균사생장을 조사하였다. 공시균주는 PDA배지에서 균사생장이 양호한 POS-012(P. ostreatus), PER-OO5(P. eryngii), GFR-001(G. frondosa), 그리고 FVE-001(F. velutipes)를 각각 공시균주로 선발하였다. 공시균주를 각종톱밥 추출액한천배지와 톱밥배지에 각각 접종하여 배양을 시킨 결과 톱밥추출액 한천배지에서는 아카시아(17번), 느티나무(20번), 표고균을 접종하지 않은 강참나무(1번, 15번)톱밥에서 가장 양호한 균사생장을 보였으며, 톱밥배지에서는 톱밥추출액 한천배지와는 다르게 표고재배에 이용하는 참나무류에서는 균사생장이 저조하였고 느티나무(20번), 벚나무(19번), 오리나무(18번), 은수원사시나무(16번), 밤나무(14번)등에서 양호한 균사생장을 보였다. 그러나 표고버섯 재배도중 흑부병과 Hypocrea에 피해를 입은 골목을 재료로 톱밥을 제조한 경우는 비교적 양호한 균사생장을 보여 이는 재활용이 가능하나, 정상적으로 표고버섯재배가 이루어진 폐골목과 표고 이외의 담자균이 생장한 경우에는 공시 식용균의 균사생장이 저조하여 재활용에 적합하지 않은 것으로 판단된다.

• Archives of Pharmacal Research
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• 제16권1호
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• pp.36-42
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• 1993

To find biologically active components of the higher fungi of Korea, the carpophores of Auricularia polytricha, a well-known edible mushroom, were extracted with 0.14 M NaCl solution. The extract was successively fractionated by adding ammonium sulfate at various concentrations, and the respective precipitates were separated by centrifugation, then dialyzed and freeze-dried. When a does of 60 mg/kg of each was injected i.p. into ICR mice, the fraction which precipitated at 20% ammonium sulfate showed the highest toxicity, killing seven out of seven mice within two days. The fraction obtained at 40% ammonium sulfate showed the second highest toxicity. The two fractions were named auritoxin I and II after the genus name. However, they Nere shown to have nearly identical composition by physicochemical and 6.8% protein. The polysaccharide moiety was found to have 12.3% $\alpha$-linkage and 87.7% $\beta$-linkage and to be a heteromannoglucan consisting of 45.1% glucose, 435 mannose and 11.0% xylose. The protein moiety contained ten amino adids. The molecular weight of the toxin was $1.5\times10^6$ dalton by Sepharose CL-4B gel filtration. The modian lethal doses of auritoxin in mice were 56.4, 157.2 and 454.6 mg/kg by i.p., s.c. and p.o.administrations, respectively. The signs of intrxication were convulsion during the first 30 minutes after the injection, coma or sleeping within an hour, termor, lacrimation, nasal bleeding congestion, and death in 24 hours. Smong the various organs, the spleen was found to be enlarged remarkably. Human platelet aggregation was inhibited by the addition of auritoxin. The activity of malic dehydrogenase in vitro was inhibited by the toxin.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.828-836
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• 2015

Based on its α-amylase activity at pH 5.0 and optimal pH of the crude enzyme, a strain (named B-5) with acid α-amylase production was screened. The B-5 strain was identified as Bacillus amyloliquefaciens through morphological, physiological, and biochemical characteristics analysis, as well as 16S rDNA phylogenetic analysis. Its α-amylase gene of GenBank Accession No. GU318401 was cloned and expressed in Escherichia coli. The purified recombinant α-amylase AMY-Ba showed the optimal pH of 5.0, and was stable at a pH range of 4.0-6.0. When hydrolyzing soluble starch, amylose, and amylopectin, AMY-Ba released glucose and maltose as major end products. The α-amylase AMY-Ba in this work was different from the well-investigated J01542-type α-amylase which also came from B. amyloliquefaciens. AMY-Ba exhibited notable adsorption and hydrolysis ability towards various raw starches. Structure analysis of AMY-Ba suggested the presence of a new starch-binding domain at its C-terminal region.

• 한국균학회지
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• 제26권2호통권85호
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• pp.194-199
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• 1998

본 실험에서 공시균주로 사용된 비늘버섯속균은 1997년도 8월초부터 10월말까지 강원도내의 삼림(삼악산, 오대산, 장원대학 연습림)에서 채집된 것으로서 갓의 지름이 $3{\sim}8\;cm$로 편평형이며 갓표면은 습하면 점성이 있고 황갈색이며 주름살은 완전 붙은형이며 약간 빽빽하고 처음에는 황백색이나 차차 갈색으로 변하기도 한다. 식용 가능한 비늘버섯속균(Pholiota sp.)을 이용하여 자실체 생산에 관한 연구를 한 결과 공시균주인 검은비늘버섯(Pholiota adiposa)의 균사생육에 적합한 온도는 $25{\sim}30^{\circ}C$로, 자실체 형성에 적합한 온도는 $15{\pm}1^{\circ}C$로 조사되었다. 농업적으로 이용이 가능한 산업용 액체배지의 탄소원으로는 황백당(brown sugar)을 사용하였으며, 질소원으로는 대두분(soybean flour)을 사용하였다. 본 균의 인공자실체는 포플러 톱밥과 쌀겨를 4:1로 혼합한 병재배를 통해 형성되었으며 액체배양장치로는 배양액량이 8 L인 원통형의 내열성 유리병을 선발하여 이용하였다.

• 한국버섯학회지
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• 제12권2호
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• pp.82-87
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• 2014

Commonly known as the button mushroom, Agaricus bisporus is one of the most widely cultivated mushroom species of edible fungi. In the breeding of new button mushroom, Seolwon was developed by crossing two homokaryons. Because of the predominantly pseudohomothallic life cycle, only a small percentage of homokaryotic meiospores are produced, which do not fruit. Homokaryotic cultures derived from these types of single spores produce a vegetative mycelium that contain a variable number of genetically identical nuclei per cell. After crossing two homokaryons, hybrids were cultivated on a small scale and on a commercial scale at a farm. The spawn was made by a commercial spawn producer and the spawned compost by a commercial compost producer. Mycelial growth of Seolwon on CDA was better at $25^{\circ}C$ when it was compared with that of Seolgang. The mature cap shape of new strain Seolwon is oblate spheroid and the immature cap shape is round to oblate spheroid. The cap diameter was 39.7 mm on average. In comparison with white strain Seolgang, the strain had a yield that was 11% higher. It produced fruiting bodies which had a higher weight on average per fruiting body and were 9.7% firmer with a good shelf life. Days of fruiting body were 1-2 days later than those of Seolgang. The physical characteristics such as springiness, chewiness, adhesiveness, gumminess were better than that of Seolgang.

• Toxicological Research
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• 제6권2호
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• pp.159-166
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• 1990

The ability of many toxigenic fungi to invade and develop in a wide variety of raw ingredients of human diet renders human exposure to mycotoxing very difficult to avoid. Most of the energy-rich commodities, such as cereal grains, oil seeds, tree nuts, and dehydrated fruits, are susceptible to mycotoxin contamination. Mycotoxins therefare have been recognized as an important class of hazardous substances in the human food chain. Although human exposure to mycotoxins is largely through ingestion, inhalation and skin contact may also be significant under conditions other than consumption of foods. Human ingestion of mycotoxins is due to consumption of contaminated dietary ingredients and the edible tissues and products of domestic animals that have been exposed to mycotoxins in moldy feed. Large scale acute human mycotoxicoses, such as ergotism in France, alimentary toxic aleukia in Russia, yellow rice syndrome in Japan, endemic nephropathy in Balkan countries, and acute aflatoxin poisonings in India and Taiwan, have been well documented, indicating that mycotoxicosis is a global problem. In some incidents, hundreds of victims were killed and many more became seriously ill. The mycotoxins that have been implicated in the etiology of these human diseases include aflatoxins, citreoviridin, cyclopiazonic acid, ergot alkaloids, moniliformin, ochratoxin A, trichothecenes, tenuazonic acid, and zearalenone. Among these, aflatoxins have been also implicated in the etiology of human primary liver cancer in those high-incidence countries in Africa and southeast Asia. It is well recognized that cause-effect relationship between mycotoxins and human diseases is very difficult to establish, especially for the cancer connection. Careful risk assessment must be performed to determine whether a mycotoxin indeed warrants costly regulatory actions.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.35-35
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• 2015

Pleurotus eryngii has recently become a major cultivated mushroom; it uses tetrapolar heterothallism as a part of its reproductive process. Sexual development progresses only when the A and B mating types are compatible. Such mating incompatibility occasionally limits the efficiency of breeding programs in which crossing within loci-shared strains or backcrossing strategies are employed. Therefore, understanding the mating system in edible mushroom fungi will help provide a short cut in the development of new strains. We isolated and identified pheromone and receptor genes in the B3 locus of P. eryngii and performed a functional analysis of the genes in the mating process by transformation. A genomic DNA library was constructed to map the entire mating-type locus. The B3 locus was found to contain four pheromone precursor genes and four receptor genes. Remarkably, receptor PESTE3.3.1 has just 34 amino acid residues in its C-terminal cytoplasmic region; therefore, it seems likely to be a receptor-like gene. Real-time quantitative RT-PCR (real-time qRT-PCR) revealed that most pheromone and receptor genes showed significantly higher expression in monokaryotic cells than dikaryotic cells. The pheromone genes PEphb3.1 and PEphb3.3 and the receptor gene PESTE3.3.1 were transformed into P5 (A3B4). The transformants were mated with a tester strain (A4B4), and the progeny showed clamp connections and a normal fruiting body, which indicates the proposed role of these genes in mating and fruiting processes. This result also confirms that PESTE3.3.1 is a receptor gene. In this study, we identified pheromone and receptor genes in the B3 locus of P. eryngii and found that some of those genes appear to play a role in the mating and fruiting processes. These results might help elucidate the mechanism of fruiting differentiation and improve breeding efficiency.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.41-41
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• 2014

Agaricus bisporus, commonly known as the button mushroom, is the most widely cultivated species of edible fungi. Low frequency of recombination ratio and homokaryotic or monokaryotic spore on meiotic basidia form obstacles for breeding programs. Since the first hybrid varieties for white button mushrooms were released in Europe, new varieties released afterwards were either identical of very similar to these first hybrids on morphologies. Therefore, different DNA markers have been used to define unique varieties of A. bisporus strains. Aim of this study is to assess the genetic diversity of different A. bisporus strains in Korea. Twelve UFP (Universal fungal primer, JK BioTech. Ltd), 12 simple sequence repeat (ISSR) and 30 SSR primers were used to assess genetic diversity of monokaryotic and dikaryotic Agaricus bisporus strains including other 19 Agaricus spp. Of them, four UFP, four SSR primers, $(GA)_8T$, $(AG)_8YC$, $(GA)_8C$ and $(CTC)_6$ and seven SSR markers produced PCR polymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted for UPGMA cluster analysis. Forty five strains of A. bisporus are genetically clustered into 6 groups, showing coefficient similarity from 0.75 to 0.9 among them. In addition, genetic variations of monokaryotic and dikaryotic Agaricus bisporus strains were partially detected by PCR technologies of this study. The varieties, Saea, saedo, Saejeong and Saeyeon that have recently been developed in Korea were involved in the same group with closely genetic relationship of coefficient similarity over 0.96, whereas, other strains were genetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese.

• 한국버섯학회지
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• 제9권3호
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• pp.105-109
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• 2011

표고 봉지재배시 적정한 영양원을 선발하기 위하여 참나무톱밥과 혼합하여 실험한 결과 T5의 pH는 4.7로서 T1(대조구)과 대등하였다. 균사 생장량은 T5에서 배양 35일경에 모두 생장하였으며, 대조와 비슷한 경향을 나타내었다. 혼합배지에 따른 배양특성은 T5가 배양일수 87일로 T1(대조)과 대등하였으며, T1, T2 및 T5의 갈변정도가 다른 처리구에 비해 우수하였고, 배양율도 100%이었다. 혼합배지에 따른 재배기간을 조사한 결과 초발이 소요일수, 생육기간, 재배일수 모두 T5처리구가 T1(대조)과 대등하였다. 혼합배지에 따른 수확주기별 수량 및 상품화율은 T5에서 수량이 348g/kg으로 T1(대조구)에 비해 높았으며, 생물학적 효율은 34%로 다른 처리구들에 비해 가장 높았다.