• Title/Summary/Keyword: N. crassa

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Heavy Metal Accumulation in Neurospora crassa (Neurospora crassa의 중금속 축적)

  • 우승희;김옥경;이연희
    • Korean Journal of Microbiology
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    • v.31 no.4
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    • pp.300-305
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    • 1993
  • Neurospora crassa accumulated cadmium. iron, manganese and lead in the mycelium. The growth of N. crassa was inhibited in the presence of cadmium but not in the presence of iron or manganese. In the presence of lead. the growth of N. crassa was accelerated. In the presence of cadmium. mycelium became thick and a conidiospore grew into a mycelial ball instead of normal threadlike gro~1h. Each metal wa'i accumulated in different subcellular organelles bound to protein and induced different proteins.

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Cyanide Degradation by Two Recombinant Cyanide Hydratases (Recombinant Cyanide Hydratases에 의한 시안화물 분해)

  • Kwon, Sung-Hyun;Cho, Dae-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.6
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    • pp.1287-1291
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    • 2009
  • The genes of cyanide hydratase(CHT), a kind of nitrilases whichhydrolyze cyanide to formamide were extracted from N. crassa and A. nidulans, the two fungal strains. The recombinant forms of the CHT originated from N. crassa and A. nidulans were prepared with N-terminal hexahistidine purificationtags or no tags, and expressed in E. coli. The enzymes were purified using immobilized metal affinity chromatography. They were compared according to their pH activity profiles, and kinetic parameters. The N. crassa CHT has the wider pH range of activity above 50% and three-fold higher turnover rate (6.6 ${\times}$ $10^8$ $min^{-1}$) than the A. nidulans, meanwhile the CHT of A. nidulans has the higher $K_m$ value. Expression of CHT in both N. crassa and A. nidulans were induced by the presence of KCN, regardless of any presence of nitrogen sources. Max. 82% of KCN was degraded in 60 min for biological degradation tests.

Purification and gene cloning of .alpha.-amylase of neurospora crassa (Neurospora crassa에서 알파아밀라제의 정제 및 유전자의 클로닝)

  • 강일구;김미숙;양철학
    • Korean Journal of Microbiology
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    • v.26 no.2
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    • pp.73-81
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    • 1988
  • $\alpha$-Amylase (EC.3.2.1.1) of Neurospora crassa (ATCC9279) was cloned in E. coli HB101 using shotgun method, and the enzymes isolated from both N. crassa and E. coli were compared. Chromosomal DNA isolated from the spores of N. crassa was partially digested with PstI restriction endonuclease and rejoined to pBR322 which had been digested with the same enzyme. The resulting recombinant DNA were introduced into E. coli HB101 which had competancy by treating with $CaCl_{2}$. As the result, about 8000 colonies which showed tetracycline resistance were selected and two of the colonies which had 13.5Kb recombinant plasmid exhibit starch degrading activity on starch-containing plate when treated with D-cycloserine. $\alpha$-Amylases from both N.crassa and E. coli were isolated by using ammonium sulfate precipitation, DEAE-cellulose ion exchange column chromatography and Bio-Gel P150 gel foltration column. As the result, about 81.3 fold and 5.6 fold purifications in specific activities were obtained respectively, and specific activities of the gel filtrates were 6.1u/mg and 85u/mg respectively. The properties of both enzymes were compared and they showed quite the similar patterns in optimal temperature, optimal pH and had same molecular weight about 100,000 daltons on gel filtration method. Optimal temperatures for both enzymes were $70^{\circ}C$ and optimal pH were about 6 and 10.

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Restoration of Saccharomyces cerevisiae coq7 Mutant by a Neurospora crassa Gene (Neurospora crassa 유전자에 의한 Saccharomyces cerevisiae coq7 돌연변이의 회복)

  • 김은정;김상래;이병욱
    • Journal of Life Science
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    • v.13 no.6
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    • pp.933-942
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    • 2003
  • CoenzymeQ is a quinone derivative with a long isoprenoid side chain. It transports electrons in the respiratory chain located in the inner mitochondrial membrane of eukaryotes and the plasma membrane of prokaryotes. It also functions as an antioxidant. Saccharomyces cerevisine coq mutants, that are deficient coenzyme Q biosynthesis fail to aerobically grow. They are not able to grow on non-fermentable carbon sources, such as glycerol, either The putative $coq^{-7}$ gene involved in coenzyme Q biosynthesis of Neurospora crassa was cloned and used for complementation of S. cerevisiae coq7 mutant. The predicted amino acid sequence of N. crassa COQ7 showed about 58% homology with Coq7p of S. cerevisiae. The growth rate of S. cerevisiae $coq^7$ mutant transformed with the N. crassa $coq^{-7}$ gene was restored to the wild-type level. The complemented 5. cerevisiae strain was able to grow with glycerol as a sole carbon source and showed less sensitivities to linolenic acid, a polyunsaturated fatty acid.

Functional Expression of the Neurospora crassa coq-4 Gene in Saccharomyces cerevisiae. (Saccharomyces cerevisiae에서 Neurospora crassa coq-4 유전자의 기능적 발현)

  • 김은정;최상기;천재우;오계헌;이병욱
    • Korean Journal of Microbiology
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    • v.40 no.2
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    • pp.73-80
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    • 2004
  • Coenzyme Q is a quinone derivative that acts as a lipid electron carrier in the respiratory chain located at mito-chondrial inner membrane in eucaryotes or plasma membrane in procaryotes and also functions as antioxidant. A putative Neurospora crassa coq-4 gene was cloned and functionally expressed in Saccharomyces cerevisiae coq4 mutant. Complemented S. cerevisaie mutant strain was able to produce coenzyme $Q_{6}$ and showed a normal growth rate. They also showed less sensitivities to polyunsaturated fatty acids such as linoleic acid or linolenic acid. The predicted sequence of N. crassa COQ4 is consisted of 347 amino acids with a molecular mass of 39.7 kDa and showed 35% identity and 52% similarity with that of S. cerevisiae.

Transcription level of the ars-1 promoter of Neurospora crassa (Neurospora crassa ars-1 프로모터의 발현율 조사)

  • 이병욱;구상호
    • Journal of Life Science
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    • v.13 no.2
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    • pp.191-196
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    • 2003
  • The ars gene of the Neurospora crassa encodes arylsulfatase and is expressed under sulfur limitation. An ars-1 promoter(Pars) translationally-fused to a lacZ gene was transformed into the N. crassa RLM 35-35, a his-3 inl strain and integrated into the his-S locus by a single crossover homologous recombination. $\beta$-galactosidase specific activity was measured from mycelia grown in sulfur-limited Vogel's medium. Enzyme activity reached its maximum at 14 hour after the shift to derepressing condition. When activity from homokaryon generated by microconidiation was measured, it was 17% a higher than that from heterokaryon.

Comparison of Cyanide Degrading Enzymes Expressed from Genes of Fungal Origin

  • Cho, Dae-Chul;Kwon, Sung-Hyun
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1221-1226
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    • 2008
  • A variety of fungal species are known to degrade cyanide through the action of cyanide hydratase, a specialized nitrilases which hydrolyze cyanide to formamide. This work is a report on two unknown and un-characterized members from Neurospora crassa and Aspergillus nidulans. Recombinant forms of three cyanide hydratases (CHT) originated from N. crassa, Gibberella zeae, and A. nidulans were prepared after their genes were cloned with N-terminal hexahistidine purification tags, expressed in E. coli and purified using immobilized metal affinity chromatography. These enzymes were compared according to their pH activity profiles, and kinetic parameters. Although all three were similar, the N. crassa CHT has the widest pH range of activity above 50% and highest turnover rate ($6.6{\times}10^8min^{-1}$) among them. The CHT of A. nidulans has the highest Km value of the three nitrilases evaluated in here. Expression of CHT in both N. crassa and A. nidulans were induced by the presence of KCN, regardless of any presence of nitrogen sources. These data can be used to determine optimal procedures for the enzyme uses in the remediation of cyanide-containing wastes.

Diet of Chaetognaths Sagitta crassa and S. nagae in the Yellow Sea Inferred from Gut Content and Fatty Acid Analyses (위 내용물 및 지방산 구성을 통한 황해 모악류(Sagitta crassa와 S. nagae)의 먹이 섭식 특성)

  • Yoon, Hyunjin;Ko, Ah-Ra;Kang, Jung-Hoon;Choi, Joong Ki;Ju, Se-Jong
    • Ocean and Polar Research
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    • v.38 no.1
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    • pp.35-46
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    • 2016
  • To understand the diet of chaetognaths, the gut content and fatty acid trophic makers (FATMs) of Sagitta crassa and S. nagae, which are the most predominant species of chaetognath in the Yellow Sea, were analyzed. Gut contents of the two species examined by microscopic analysis revealed that copepods are the major components of the diet (> 70% of gut contents) and there was no significant changes in the gut contents of two species collected in spring and summer season. Although 16:0, 20:5(n-3) (Eicosapentaenoic acid) and 22:6(n-3) (Docosahexanoic acid), which are known as phytoplankton FA markers, were the most dominant among the fatty acids in both chaetognath species, the detection of copepod FA markers, 20:1(n-9) (Gadoleic acid) and 22:1(n-11) (Cetoleic acid), provided evidence that their food sources include copepods. These results suggest that S. crassa and S. nagae are carnivores and mainly feed on copepods in the Yellow Sea.

Cellular and Molecular Responses of a Filamentous Fungus Neurospora Crassa to Non-thermal Plasma at Atmospheric Pressure

  • Park, Gyung-Soon;Ryu, Young-Hyo;Hong, Young-June;Uhm, Han-Sup;Choi, Eun-H.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.476-476
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    • 2012
  • Although plasma is an efficient means of microbial sterilization, mechanism of plasma effect on microorganisms still needs to be clarified. In addition, a limited number of studies are available on eukaryotic microorganisms such as yeast and fungi in relation to plasma application. Thus, we investigated cellular and molecular aspects of plasma effects on a filamentous fungus, Neurospora crassa by making use of argon plasma jet at atmospheric pressure. The viability and cell morphology of N. crassa spores exposed to plasma were both significantly reduced depending on the exposure time when treated in water. The intracellular genomic DNA content was dramatically reduced in fungal tissues after a plasma treatment and the transcription factor tah-3 was found to be required for fungal tolerance to a harsh plasma environment.

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Enchancement of Gamma-Aminobutyric Acid Production by Co-Localization of Neurospora crassa OR74A Glutamate Decarboxylase with Escherichia coli GABA Transporter Via Synthetic Scaffold Complex

  • Somasundaram, Sivachandiran;Maruthamuthu, Murali Kannan;Ganesh, Irisappan;Eom, Gyeong Tae;Hong, Soon Ho
    • Journal of Microbiology and Biotechnology
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    • v.27 no.9
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    • pp.1664-1669
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    • 2017
  • Gamma-aminobutyric acid is a precursor of nylon-4, which is a promising heat-resistant biopolymer. GABA can be produced from the decarboxylation of glutamate by glutamate decarboxylase. In this study, a synthetic scaffold complex strategy was employed involving the Neurospora crassa glutamate decarboxylase (GadB) and Escherichia coli GABA antiporter (GadC) to improve GABA production. To construct the complex, the SH3 domain was attached to the N. crassa GadB, and the SH3 ligand was attached to the N-terminus, middle, and C-terminus of E. coli GadC. In the C-terminus model, 5.8 g/l of GABA concentration was obtained from 10 g/l glutamate. When a competing pathway engineered strain was used, the final GABA concentration was further increased to 5.94 g/l, which corresponds to 97.5% of GABA yield. With the introduction of the scaffold complex, the GABA productivity increased by 2.9 folds during the initial culture period.