• The Plant Pathology Journal
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• 제26권3호
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• pp.264-266
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• 2010

A fungus that can capture nematodes by means of sessile adhesive knobs was isolated from rotten wood in Uiseong, Korea. It was found to produce single, spindle-shaped, 3-4 septate (commonly 4-septate) conidia, $44.8\;{\mu}m$ (range, $41.6-50.1\;{\mu}m$) long and $13.3\;{\mu}m$ (range, $10.7-15.4\;{\mu}m$) wide. Conidiophores were found to be hyaline, erect, straight, and $202.7-245.7\;{\mu}m$ high. On the basis of these morphological features, the fungus was identified as Monacrosporium phymatopagum. This is the first report of M. phymatopagum in Korea which can be a potential biological control resource of plant parasitic nematode.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.852-858
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• 2008

An extracellular protease (Mc1) was isolated from the nematode-trapping fungus Monacrosporium cystosporium by gel filtration, anion-exchange, and hydrophobic interaction chromatographies. This protease had a molecular mass of approximately 38 kDa and displayed an optimal activity at pH 7-9 and $56^{\circ}C$ (over 30 min). Its proteolytic activity was highly sensitive to the serine protease inhibitor PMSF (phenylmethylsulfonylfluoride, 0.1 mM), indicating that it belonged to the serine-type peptidase group. The Michaelis constant ($K_m$) and $V_max$ for substrate N-Suc-Ala-Ala-Pro-Phe-pNA were $1.67{\times}10^{-4}\;M$ and 0.6071 $OD_{410}$ per 30 s, respectively. This protease could degrade a broad range of substrates including casein, gelatin, BSA (bovine serum albumin), and nematode cuticle. Moreover, the enzyme could immobilize the free-living nematode Panagrellus redivivus and the pine wood nematode Bursaphelenchus xylophilus, suggesting that it might playa role in infection against nematodes. The encoding gene of Mc1 was composed of one intron and two exons, coding for a polypeptide of 405 amino acid residues. The deduced amino acid sequence of Mcl showed 61.4-91.9% identity to serine proteases from other nematode-trapping fungi. Our results identified that Mcl possessed biochemical properties including optimal reaction condition and substrate preference that are different from previously identified serine proteases.

• Journal of Microbiology
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• 제43권5호
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• pp.417-423
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• 2005

In this study, the nematode-trapping fungus, Monacrosporium sphaeroides, was transformed with a plasmid harboring the hygromycin B phosphotransferase gene, via restriction enzyme-mediated integration (REMI). Frequencies of up to 94 transformants ${\mu}g^{-1}$ per linearized plasmid DNA were obtained by optimizing the PEG concentration, as well as the category and quantity of the added restriction enzyme. $90\%$ of the transformants were determined to be stable for drug resistance when 20 randomly selected transformants were tested. Southern analyses revealed that the transforming DNA was integrated into the M. sphaeroides genome either with or without rearrangement. Five mitotic stable mutant strains were obtained using this approach, all of which had been altered with regard to sporulation capacity and pathogenicity toward nematodes. Southern blot analyses of the five mutants revealed that foreign plasmid DNA had integrated into the genome. Three of the mutants, Tms2316, Tms3583 and Tms1536, exhibited integration at a single location, whereas the remaining two, Tms32 and Tms1913, manifested integration at double or multiple locations. Our results suggest that the transformation of M. sphaeroides via REMI will facilitate insertional mutagenesis, the functional analysis of a variety of genes, and the tagging or cloning of genes of interest.

• 한국응용곤충학회지
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• 제58권1호
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• pp.9-13
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• 2019

선충포식성 곰팡이는 선충을 포획하기 위하여 다양하고 특수한 기관을 사용한다. 국내 성주지역의 참외 경작지 뿌리 주변의 토양에서 3차원 접착 고리를 형성하여 선충을 포획하는 곰팡이를 분리하였다. 곰팡이의 미세형태 구조를 관찰한 결과 분생포자병은 직립형으로 길이는 $290{\sim}528(342.8){\mu}m$으로 길었으며, 계란형의 $30.5{\times}20.3{\mu}m$ 크기를 가진 1~3개의 분생포자를 형성하였다. 균주의 rDNA의 5.8 S 영역의 염기서열을 분석한 결과, Arthrobotrys속의 계통군에 속하였으며, 특히 Arthrobotrys sinensis와 99%의 유사성을 보였다. 형태적 특징과 분자생물학적 계통 분석을 바탕으로 본 균주는 A. sinensis로 확인되었으며, 이는 국내 미기록종으로 식물기생성선충의 생물학적 조절을 위한 하나의 자원이 될 수 있다.

• 생명과학회지
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• 제10권4호
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• pp.403-407
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• 2000

잎들깨 재배지에서 직$\cdot$간접적으로 피해를 입히는 뿌리썩이선충(Pratylenchus spp.)의 생물학적 방제를 위해서 3종의 선충포식성 곰팡이, Arthrobotrys oligospora, A. conoides와 A. dactyloides의 선충방제 효과를 포장시험을 통하여 검정하였다. 3종의 Arthrobotrys는 1998년 잎들깨 재배지 토양에서 분리하였으며, 이들 곰팡이들은 한천배지상에서 끈끈이그물 또는 수축성 올가미와 같은 특이한 균사구조를 형성하여 뿌리썩이선층을 포획하는 것으로 관찰하였다. 야외포장 실험결과, 대조구에서는 40일 경과 후 식물기생성 선충 및 뿌리썩이선충의 밀도가 약 3.5배 증가한 반면 선충포식성 곰팡이 A. oligospora와 A. conoides 처리구에서는 단지 선충의 밀도가 큰 증감없이 접종 전의 수준을 유지하는 효과를 보였다. 그러나 A. dactyloides 처리구에서는 식물기생성 선충의 밀도를 약 65%, 뿌리썩이 선충의 밀도를 약 53% 감소시켜, 선충포식성 곰팡이의 생물학적 방제효과가 높게 나타났다.

• The Plant Pathology Journal
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• 제23권3호
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• pp.210-211
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• 2007

Dactylella pseudoclavata that captures nematodes in adhesive networks was isolated from nematode-infested strawberry plants from Andong, Korea. It produces obclavate, 0-1 septate conidia, $30-40{\mu}m$ long and $8-11{\mu}m$ wide, with round distal ends and bases shaped like bottle-necks. The conidiophores were simple, occasionally branched, $150-300{\mu}m$ long, producing 1-4 conidia at the apex. Chlamydospores were abundant, intercalary or catenulate, yellowish to brown, globate or subglobate, wart on the surface, $30-35{\times}25-30{\mu}m$ in size. This is the first report of Dactylella pseudoclavata in Korea.

• Mycobiology
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• 제33권4호
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• pp.215-222
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• 2005

Variability in growth and sporulation of five isolates of Arthrobotrys dactyloides was studied on five agar, 6 bran and 5 grain media. Potato dextrose agar (PDA) supported maximum growth of isolate A, C and E, while growth of isolate Band D was significantly lower on this medium. On Czapek's agar and yeast glucose agar media the differentiation in the isolates in relation to growth was poor than PDA. The other two media showed much poorer differentiation. On Czapek's agar medium, sporulation was recorded in isolate B only, whereas other isolates showed rare sporulation. Among the bran media, pea bran agar medium supported maximum growth of all the isolates except isolate B. Gram and rice bran agar media were next best. However, the growth of isolate B on the gram bran agar medium was more or less equal as other isolates. On pigeon pea bran agar medium, isolate E failed to grow while other isolates recorded poor growth. On lentil bran agar medium, only isolate Band D recorded little growth, whereas other isolates failed to grow. All the isolates recorded good sporulation on bran agar media except pigeon pea and lentil bran agar media. The grain agar media supported moderate to very good growth of all the isolates. In general isolate B remained slow growing on these media except gram grain and sorghum grain agar media on which growth of this isolate was comparable to other isolates. Sporulation in general, was good on all the grain agar media. Among different substrates screened, barley grain and pea bran were found superior to others for mass culture of isolate A of A. dactyloides.