• The Plant Pathology Journal
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• 제24권3호
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• pp.352-356
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• 2008

Root discs of 4-year-old ginseng, Panax ginseng C. A. Meyer, were inoculated with the higher($10^8$ colonyforming units(CFU)/ml) and lower($10^6\;or\;10^5$ CFU/ml) initial inoculum levels of a plant-growth promoting rhizobacterium(PGPR), Paenibacillus polymyxa GBR-1 to examine rot symptom development and bacterial population changes on the root discs. At the higher inoculum level, brown rot symptoms developed and expanded on the whole root discs in which the bacterial population increased continuously up to 4 days after inoculation. In light and electron microscopy, ginseng root cells on the inoculation sites were extensively decayed, which were characterized by dissolved cell walls and destructed cytoplasmic contents. However, no rot symptoms were developed and the bacterial population increased only during the initial two days of inoculation at the lower inoculum level($10^6$ CFU/ml) of P. polymyxa GBR-1. At the lower inoculum level($10^5$ CFU/ml), boundary layers with parallel periclinal cell divisions, structurally similar to wound periderm, were formed internal to the inoculation sites, beneath which the cells were intact containing numerous normal-looking starch granules and no disorganized cell organelles, suggesting that these structural features may be related to the suppression of symptom development, a histological defense mechanism.

• 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.

• 한국지역사회생활과학회지
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• 제17권3호
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• pp.123-131
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• 2006

To compare the quality characteristics, chunggugjang was prepared with Bacillus subtilis NRLSI IV on the different inoculum levels$(10^2,\;10^4,\;10^6,\;and\;10^8 CFU/ml)$ and fermentation times(0, 12, 24, 36, and 48 hours). Although significant change in total nitrogen content was not found, the content of amino type, soluble and ammonia type nitrogen was generally increased according to the increase in fermentation time. Decomposition rate of nitrogen was also increased by fermentation time and nitrogen solubility was the highest value(62-75.9%) at 48 hour fermentation. In results of color changes, it was found that L and a value were decreased but there was no significant changes in b value as fermentation time was increased. In chunggugjang made with long fermentation time, hardness was decreased and relative viscosity of viscous substance was gradually decreased after little increase at initial fermentation time. The effect of inoculum level on hardness and relative viscosity were similar to that of fermentation time, i.e. the decrease of these at high inoculum level. In activity of V-GTP, 36 hour incubation could produce the highest value whereas no effect of inoculum level was found during fermentation except at 48 hour. In chunggugjang made with $10^2CFU/mL$ of Bacillus subtilis NRLSI IV, the content of glucose, sucrose, raffinose and stachyose was dramatically decreased at initial fermentation time and that of phytic acid, oxalic acid, citric acid, tartaric acid and malic acid was also decreased during fermentation, although the increase in acetic acid was found.

• Applied Biological Chemistry
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• 제30권4호
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• pp.311-314
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• 1987

Hemicellulose hydrolyzate를 이용한 알코올 발효 과정에서 기질의 inhibition 문제를 해결하기 위해 고농도의 inoculum을 사용하는 방법이 연구되었다. Inoculum의 농도가 25g dry cells/liter에 도달해서야 발효가 진척이 되었으며, 이 경우에 기질은 24시간 이내에 완전히 소모되었다. Furfural은 발효과정중에 Pachysolen tannophilus에 의해서 흡수가 되어 furfuryl alcohol로 대사되는 것이 확인 되었으며 furfural 성분에 의한 알콜 생성에 관한 inhibition 영향도는 non-furfural 성분에 의한 것 보다 적은 것으로 판명되었다. Hemicellulose Hydrolyzate의 알콜 발효 과정에서 비알콜 생성율은 1l당 41.8g xylose와 2.39의 furfural을 함유한 배지에서의 비알코올 생성율의 14%이었다.

• 한국미생물·생명공학회지
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• 제22권4호
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• pp.436-442
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• 1994

The characteristics of activated sludge affecting the biodegradation of plastic materials under aerobic condition were studied using cellophane film as a model system. The activated sludges of site 3, which treat a mixture of domestic sewage and supernatant of septic tank, obtained from December 1993 to April 1994 showed similar biodegradation activities. Biodegradations for 28 days reached around 80%. Viable cell number of inoculums maintained at a level of 10$^{6}$~10$^{7}$ /ml. In this range, viable cell number showed no relationship with biodegradation activities. The activa- ted sludges of site 2, which treat a mixture of domestic sewage and anaerobic digest of nightsoil, obtained four times from April 1993 to April 1994 showed very different biodegradation activities ranged from 20% to 80% for 28 days. Inoculum size affects biodegradation significantly. One percent inoculum showed the best biodegradation among the inoculum sizes of 0.1, 1.0 and 10%. Ten percent inoculum revealed inhibitory effects on the biodegradation activity which can be greatly reduced by centrifugation and filtration. Filtration was better than centrifugation in reducing inhibitory effects.

• KSBB Journal
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• 제11권5호
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• pp.600-605
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• 1996

Taxus brevifolia와 Taxus cuspidata 현탁세포배 양에서 taxa!의 생산에 가장 적합한 초기 접종농도 를 결정하기 위해 접종농도를 세포생체중량으로 2.5, 5 5, 7.5, 10 g/flask가 되도록 변화시켜 세포의 생장 과 taxol의 생산을 측정하였다. Taxus brevifolia의 경우 초기 접종농도가 높을수록 lag phase가 감소되 는 경향을 보였으며, 두 가지 세포주(Taxus bre­1 vifolia와 Taxus cuspidata)에서 모두 초기 접종농도 를 5 g/flask가 taxol의 생산에 최척 임을 확인할 수 있었다. Taxol 생산에 가장 척합한 초기 접종농도로 생장배지와 생산배지에 세포를 접종시켰을 때 생장 배지에서는 taxal이 검출되지 않았지만 6% 자당을 이용한 생산배지에서는 9일째 taxol이 최대로 생산 되었다가 이후 다시 줄어드는 경향을 보였다.

• 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.

• Applied Biological Chemistry
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• 제37권5호
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• pp.315-319
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• 1994

Pichia stipitis CBS 5776을 이용하여 볏짚 가수분해물의 fermentability를 조사하고 가수분해시 고체 강력산인 Nafion과 재래식 황산에 의한 가수분해물을 비교 검토하였다. 볏짚의 Nafion 가수분해물은 산 가수분해물보다 세포 증식 및 발효에 대한 저해 수준이 낮았으며 3.2 g/l 이상의 Pichia stipitis inoculum을 사용하면 Nafion 가수분해물의 발효에서 에탄올 생산이 가능하였다.

• 한국식물병리학회지
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• 제14권2호
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• pp.145-149
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• 1998

Four nonpathogenic isolates of Fusarium oxysporum isolated from spinach showed suppressive effect on the occurrence of the Fusarium wilt of spinach caused by F. oxysporum f. sp. sprinaciae, among which NF01 controlled the disease most effectively. And NF01 was not pathogenic to tomato, cucumber, radish and spinach. This isolate was further tested for the biological control of the disease. The isolate was not inhibitory to the growth of the pathogen on potato sucrose agar medium, however the Fusarium wilt disease occurred less by drenching spore suspension of the nonpathogenic isolate. The control effect of the isolate was higher at lower inoculum level of the pathogen than at the higher inoculum level, and in the pretreatments than the simultaneous treatment of the isolate with the pathogen inoculation. The nit mutants of the isolate were easily formed on chlorate containing media, and was reisolated selectively as nit mutant from infected soil and plants. The reisolation rate of the isolate as opposed to pathogen was high at preinoculated soil and plants relative to the simultaneous inoculation of the isolate with the pathogen.

• 한국작물학회지
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• 제28권2호
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• pp.195-201
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• 1983

벼뿌리선충(H. imamuri)의 밀도별 피해 정도와 경제적 피해 수준을 결정하고자 밀양 2003를 공시하여 폿트 시험으로 실시한 결과를 요약하면 다음과 같다. 1. 벼의 분벽은 폿트당 선충 5,000마리 이상 접종에서 감소를 보였다. 2. 선충 접종 2개월 후부터 벼의 생육 특히 뿌리 무게에 많은 영향(40.7% 감소)을 주었으며 출수기는 6일 정도 지연되었다. 3. 선충 20,000마리 접종 폿트에서 수수, 1,000립중, 등숙비율 등이 감소되어 31.2%의 감수를 보였다. 4. 선충 접종 밀도에서는 폿트당 5,000마리 수준에서부터 생육 및 수량에 영향을 주었고, 피해한계밀도는 8월 30일에 조사한 것을 기준으로 하면 벼 뿌리 생중 30g당 1,500마리 정도로 나타났다.