• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.616-623
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• 2007

The effects of initial concentration and pulsed pressurization on the inactivation of Clostridium sporogenes spores suspended in deionized water were determined during thermal processing $(TP;\;105^{\circ}C,\;0.1MPa)$ and pressure-assisted thermal processing $(PATP;\;105^{\circ}C\;and\;700MPa)$ treatments for 40 min and 5min holding times, respectively. Different inoculum levels $(10^4,\;10^6\;and\;10^8CFU/ml)$ of C. sporogenes spores suspended in deionized water were treated at $105^{\circ}C$ under 700MPa with single, double, and triple pulses. Thermally treated samples served as control. No statistical significances (p>0.05) were observed among all different inoculum levels during the thermal treatment, whereas the inactivation rates $(k_1\;and\;k_2)$ were decreased with increasing the initial concentrations of C. sporogenes spores during the PATP treatments. Double- and triple-pulsed pressurization reduced more effectively the number of C. sporogenes spores than single-pulse pressurization. The study shows that the spore clumps formed during the PATP may lead to an increase in pressure-thermal resistance, and multiple-pulsed pressurization can be more effective in inactivating bacterial spores. The results provide an interesting insight on the spore inactivation mechanisms with regard to inoculum level and pulsed pressurization.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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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.

• 한국식물병리학회지
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• 제14권1호
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• pp.46-51
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• 1998

A method for inoculum production of Botryosphaerisa dothidea was developed using cucumber disks and cereal media. Disks of cucumber fruits, and cereal media of barley, wheat, and rice seeds were inoculated with mycelial plugs of B. dothidea and incubated at 27$^{\circ}C$. Pycnidia were produced on the surface of cucumber disks and seeds after 5 days of inoculation. When the inoculated barley seeds were immersed in sterilized distilled water for 5 minutes, abundant conidia of B. dothidea were exuded from mature pycnidia. Conidia were held together by mucilage as they were released from an ostiole. Compared with the conventional method for inoculum preparation using agar media, such as potato-dextrose agar and oatmeal agar, this method could minimize the tedious work required for inoculum preparation within a shorter period of time.

• Journal of Microbiology
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• 제42권1호
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• pp.60-63
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• 2004

A sucrose-agar globule (SAG) was newly introduced to increase production of the vesicular arbuscular mycorrhizal (VAM) fungal spores, Gigaspora gigantea and Glomus fasciculatum. An SAG inoculum and a sucrose-agar globule with root exudates (SAGE) inoculum were prepared, and their spore productions were compared with a soil inoculum. When the SAGE was used as the inoculum on sucrose-agar medium plates the number of spores was increased (35% more than the soil inoculum). After the soil inoculum and SAGE were inoculated on an experimental plant, Zingiber officinale, the percentage root colonization, number of VAM spores, and dry matter content were analyzed. It was observed that the SAGE showed a higher percentage of root colonization (about 10% more), and increases in the number of spores (about 26%) and dry matter (more than 13%) for the two VAM fungal spores than the soil inoculum. The results of this study suggested that the SAGE inoculum may be useful for the mass production of VAM fungi and also for the large scale production of VAM fungal fertilizer.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.568-572
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• 2005

Saccharomyces yeast spores are more resistant to drying and storage than vegetative cells. For the mass production of yeast spores, compressed yeast was directly inoculated into a sporulation medium (SM). The effects of inoculum size and the addition of rice wine cake (RWC) into SM on the sporulation were examined using flasks. With $1\%$ inoculum of compressed yeast, $1.45{\times}10^8/ml$ of asci was obtained. The addition of $0.5\%$ RWC into SM improved the cell growth and spore yield, and the number of asci formed was $2.31{\times}10^8/ml$. The effects of culture temperature, temperature-shift, and concentrations of inoculum, potassium acetate, and RWC on the sporulation were also evaluated using a jar fermentor. The optimum temperature for spore formation was $22^{\circ}C$ where the number of asci formed was $2.46{\times}10^8/ml$. The shift of culture temperature from initial $30^{\circ}C$ for 1 day to $22^{\circ}C$ for 3 days increased the number of asci formed to $2.96{\times}10^8/ml$. The use of $2\%$ (w/v) inoculum of compressed yeast, $2\%$ potassium acetate, and $1\%$ (w/v) RWC in SM with the shift of culture temperature of initial $30^{\circ}C\;to\;22^{\circ}C$ resulted in $90\%$ sporulation ratio and formation of $6.18{\times}10^8\;asci/ml$.

• Mycobiology
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• 제36권1호
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• pp.19-23
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• 2008

Red pepper (Capsicum annum L.) roots and soils representing different agricultural management practices such as conventional (CON), no-chemical (NOC), and organic farming systems (ORG) were collected from 32 farm field sites in Kyunggi, Korea to investigate the effects of these agricultural practices on arbuscular mycorrhizal (AM) symbiosis. ORG inoculum significantly increased plant growth compared to inoculum from CON and NOC. A community analysis of AM fungi (AMF) using morphological features of spores revealed that AMF spore abundance and species diversity were significantly higher in ORG than in CON. Additionally, a community analysis of AMF colonizing roots using a molecular technique revealed higher AMF diversity in ORG than in CON. These results suggest that agricultural practices significantly influence AM fungal community structure and mycorrhizal inoculum potential.

• 식물병연구
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• 제15권3호
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• pp.217-221
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• 2009

Fludioxonil은 미국 EPA에 의해 저독성(reduced-risk) 살균제로 분류되었으며, 이 살균제는 Pseudomonas pyrrocinia가 생산하는 항균 물질인 pyrrolnitrin을 선도 물질로 하여 합성하였다. 본 연구에서는 상추 품종, 기주 식물의 생육 시기, Botrytis cinerea 포자농도, 접종원의 영양분 농도 등의 발병 조건에 따른 fludioxonil의 상추 잿빛곰팡이병에 대한 방제효과를 온실에서 실험하였다. 상추의 생육시기에 따른 fludioxonil 방제효과를 실험한 결과, 2 ${\mu}g$/ml 처리구는 어린 유묘에서 잿빛곰팡이병 방제효과가 더 높았으나, 10 ${\mu}g$/ml 이상 농도에서는 생육 시기에 따른 방제효과의 차이는 거의 없었다. 또한 fludioxonil 10 ${\mu}g$/ml 이상 농도 처리구는 B. cinerea의 포자 농도(2.5$\times$10개/ml 부터 $2{\times}10^6$ 개/ml까지)에 관계없이 모두 우수한 방제효과를 나타냈다. 반면에 fludioxonil 2 ${\mu}g$/ml은 접종원의 포자농도가 높을수록 낮은 방제효과를 보였다. 그리고 영양분농도에 따른 fludioxonil의 잿빛곰팡이병 방제효과를 실험한 결과, potato dextrose broth의 농도가 낮을수록 fludioxonil은 상추 잿빛곰팡이병에 대한 높은 방제효과를 나타냈다. 이상의 결과로부터 살균제 fludioxonil은 상추 잿빛곰팡이병에 대한 효과적인 살균제임을 알 수 있었으며, 다만 낮은 농도에서는 발병 조건에 따라 다소 낮은 방제효과를 나타낼 수 있을 것이다.

• KSBB Journal
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• 제28권6호
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• pp.400-407
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• 2013

The growth characteristics and production of color pigments by Monascus strains were investigated during liquid culture, and production of monacolin K in red mold rice was carried out by solid state fermentation. Four different Monascus ruber strains were cultured in potato dextrose yeast extract broth (PDYB) media at $25^{\circ}C$ for 15 days. The high producing strain for red pigment was not corresponded to the strain for yellow pigment. Production of red pigment was high in the strain causing the fast pH change in culture broth. Production of monacolin K in red mold rice by solid state fermentation was influenced by a combination of wet cell weight and spore density in inoculum by liquid culture. Most strains showed the high production of monacolin K in red mold rice, when submerged fermentation was carried out for 5 days as inoculum for solid state fermentation. These results suggest that submerged fermentation period of inoculum have an effect on the production of monacolin K in red mold rice by solid state fermentation, and monacolin K in red mold rice could be increased by controlling the condition of submerged fermentation for inoculum.

• 식물병과 농업
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• 제5권2호
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• pp.90-94
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• 1999

Effect of inoculum concentration inoculation method and plant age on development of clubroot disease of Chinese cabbage seedling were examined in growth chambers. Root galls were developed at the concentration of 105 resting spore or above per ml of incoulum and as the inoculum concentration became higher rate of development of root galls was faster. In the plants with root gall development fresh weight of above ground parts was reduced to 30-44% of that of healthy plants but root weight increased by 4-10 times. Growth of diseased plants was greatly reduced as compared to healthy plants. Planting in the diseased soil as a inoculation method was most effective for disease development showing uniform infections but time of initial root gall development was delayed by root soaking inoculation. Some plants inoculated by soil drenching method did not develop root galls. However root gall enlargement after its initial formation did not differ greatly among inoculation methods. Nine-day-old seedlings showed poor development of root gall but 16-days-old seedlings was found to be most adequate for inoculation for gall development.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.21-25
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• 2002

To maximize and sustain the productivity of Monascus pigments, various environmental and nutritional parameters, such as the initial moisture content, pH, inoculum size, sample size, and nutrient supplement, that influence pigment production were evaluated in solid-state cultures as follows: initial moisture content, $50\%;$ pH, 6.0; inoculum size $1\;\times\;10^4$ spore cells $(grams\;of\;dry\;solid\;substrate)^{-1};$ sample size, 300 g. All supplementary nutrients (carbon, nitrogen, and mineral sources) added has inhibitory effects on the cell growth and red pigment production. In open tray culture the maximum biomass yield and specific productivity of red pigments were 223 mg DCW $(grams\;of\;initial\;dry\;substrate)^{-1}$ and, $47.6\;OD_{500}\;(DCW\;grams)^{-1}h^h{-1}$ respectively.