• Title, Summary, Keyword: sporulation

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Application of LFH-PCR for the Disruption of SpoIIIE and SpoIIIG of B. subtilis

  • Kim, June-Hyung;Kim, Byung-Gee
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.327-331
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    • 2000
  • The application of LFH-PCR(long flanking homology region-PCR) for Bacillus subtilis gene disruption is presented. Without plasmid- or phage-vector construction, only by PCR, based on a DNA sequence retrieved from B. subtilis genome data base, kanamycin resistance gene was inserted into two genes of B. subtilis involved in sporulation, spoIIIE and spoIIIG. The effect of gene disruption on subtilisin expression was examined and the sporulation frequency of two mutants was compared to that of the host strain. For this purpose, only 2 or 3 rounds of PCR were required with 4 primers. We first demonstrated the possibility of LFH-PCR for rapid gene disruption to characterize an unknown functional gene of B. subtilis or other prokaryote in the genomic era.

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Expression of Developmentally Regulated Promoter of Alkali-tolerant Bacillus sp. YA-I4 (알칼리 내성 Bacillus sp. YA-14에서 유래된 생육단계 조절 promoter의 발현)

  • 박영서;구본탁;박희경;유주현;김진만
    • Microbiology and Biotechnology Letters
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    • v.18 no.4
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    • pp.429-432
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    • 1990
  • The promoter isolated from chromosomal DNA of an alkali-tolerant Bacillus sp. YA-14 was subcloned and biochemically characterized. Also the relationships between the promoter activity and sporulation were investigated. In alkali-tolerant Bacillus sp. and Bacillus subtilis, the activity of promoter began to increase at the onset of sporulation with the same mode, and repressed in the presence of 1.0% (wtv) glucose. Among five spoO genes, three epoO genes (spoOB, spoH, spoOJ) were required for promoter expression.

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Aggressiveness in Plasmopara halstedii (sunflower downy mildew)

  • Sakr, Nachaat
    • The Plant Pathology Journal
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    • v.27 no.2
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    • pp.110-115
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    • 2011
  • Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) pathotypes: 100, 300, 304, 314, 704, 710 and 714. Aggressiveness criteria including percentage infection, latent period, sporulation density and reduction of hypocotyl length (dwarfing) were analysed in one sunflower inbred line showing a high level of quantitative resistance. Genetic relationships were detected between the seven pathotypes using 12 EST-derived markers. Pathotypes 100, 300, 304 and 314 were characterized with shorter latent period and higher sporulation density than pathotypes 710, 704 and 714. All pathotypes showed high percentage infection values and caused a large reduction in seedling size except for pathotype 314 involved in dwarfing. Pathotypes 714, 704 and 314 had an intermediary genetic position between the pathotypes 100 and 710. No correlation was detected between aggressiveness traits and EST genotypes.

Molecular Cloning and Analysis of Sporulation-Specific Glucoamylase (SGA) Gene of Saccharomyces diastaticus

  • Kang, Dae-Ook;Hwang, In-Kyu;Oh, Won-Keun;Lee, Hyun-Sun;Ahn, Soon-Cheol;Kim, Bo-Yeon;Mheen, Tae-Ick;Ahn, Jong-Seog
    • Journal of Microbiology
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    • v.37 no.1
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    • pp.35-40
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    • 1999
  • Sporulation-specific glucoamylase (SGA) gene was isolated from genomic library of Saccharomyces diastaticus 5114-9A by using glucoamylase non-producing mutant of S. diastaticus as a recipient. When the glucoamylase activities of culture supernatant, periplasmic, and intracellular fraction of cells transformed with hybrid plasmid containing SGA gene were measured, the highest activity was detected in culture supernatant. SGA produced by transformant and extracellular glucoamylase produced by S. diastaticus 5114-9A differed in enzyme characteristics such as optimum temperature, thermostability, and resistance to SDS and urea. But the characteristics of SGA produced by sporulating yeast cells and vegetatively growing transformants were identical.

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Spore Inoculum Optimization to Maximize Cyclosporin A Production in Tolypocladium niveum

  • Lee, Mi-Jin;Lee, Han-Na;Han, Kyu-Boem;Kim, Eung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.913-917
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    • 2008
  • The cyclic undecapeptide, cyclosporin A (CyA), is one of the most commonly prescribed immunosuppressive drugs. It is generated nonribosomally from a multifunctional cyclosporin synthetase enzyme complex by the filamentous fungus Tolypocladium niveum. In order to maximize the production of CyA by wild-type T. niveum (ATCC 34921), each of three culture stages (sporulation culture, growth culture, and production culture) were sequentially optimized. Among the three potential sporulation media, the SSMA medium generated the highest numbers of T. niveum spores. The SSM and SM media were then selected as the optimal growth and production culture media, respectively. The addition of valine and fructose to the SM production medium was also determined to be crucial for CyA biosynthesis. In this optimized three-stage culture system, 3% of the spore inoculum generated the highest level of CyA productivity in a 15-day T. niveum production culture, thereby implying that the determination of an appropriate size of T. niveum spore inoculum plays a critical role in the maximization of CyA production.

Nucelear Degeneration During Reduced Sporogenesis in Blastocladiella emersonii (Blastocladiella emersonii의 단축된 포자형성과정에서 관찰된 핵의 소멸)

  • Youn Hyun-Joo;Cho Chung-Won
    • Korean Journal of Microbiology
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    • v.40 no.4
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    • pp.282-285
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    • 2004
  • In Blastocladiella emersonii, a member of zoosporic fungi, development of small sporangia containing a few nuclei can be induced. During these reduced sporogenesis, degeneration of some of the nuclei was observed within the sporangia. This observation supports the hypothesis that the nuclear degeneration is an essential part of sporulation. Morphological changes associated with the nuclear degeneration were similar to those of the autophagy of cytoplasm. This system of nuclear degeneration would become the good model system for the study of autophagy.