• Current Research on Agriculture and Life Sciences
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• 제27권
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• pp.21-28
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• 2009

벼의 약 및 현미 배양효율과 관련된 DNA marker를 이용하여 인디카형 벼 품종인 'IR 36'의 조직배양 효율을 개선하기 위하여 실험한 결과를 요약하면 다음과 같다. 벼품종 간에 약 및 현미배양 효율을 비교한 결과 자포니카 > 통일형 > 인디카 형의 순으로 나타났다. 그러나 MGRI집단의 약배양에서 식물체분화율이 높은 계통으로 선발된 'MGRI 079'와 'MGRI 036'의 약배양 효율은 각각 19.8%, 19.9%로 가장 높게 나타났다. 'MGRI 079'에 'IR 36'이 여교배되어 양성된 $BC_2F_4$ 90 계통에 대한 marker검정을 실시하여 positive band를 나타내는 34계통을 선발할 수 있었다. 선발된 34계통 중 10 계통의 약배양에서 캘러스 형성률은 'IR 36' 보다 현저히 높았다. 선발된 10 계통의 현미배양에서도 캘러스형성 능력과 식물체재분화율이 'IR 36' 보다 높게 나타났다. $BC_2F_4$ 계통 중에서 식물체분화능력이 높은 계통으로 선발된 $BC_2F_4$-28은 간장이 'IR 36'보다 큰 편이었으나 출수기와 미립특성은 'IR 36'과 비슷하였다.

• Preventive Nutrition and Food Science
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• 제12권4호
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• pp.251-258
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• 2007

Thermal resistance and heat activation characteristics of Clostridium botulinum ATCC 25763 spores were evaluated. The effects of nisin and pH on the activation and subsequent germination were also investigated. Spores of C. botulinum were not inactivated by heat treatments up to $92^{\circ}C$ for 2 hr. Heat treatment at $85^{\circ}C$ for 90 min was selected as the optimal activation condition based on monitoring subsequent germination. L-alanine alone or in combination with L-cysteine was not sufficient to germinate the spores of this strain. Tryptone-Peptone- Glucose-Yeast extract (TPGY) broth supplemented with L-alanine was used as a suitable germination medium. Decreasing pH of activation suspension increased the degree of phase darkening, i.e., germination. In addition, the presence of nisin during activation increased the degree of phase darkening. The majority of spore populations were dormant at a pH of less than 2.8, and these populations required heat activation to increase the culturability on TPGY agar medium. However, extended heating in the presence of nisin at pH 2.8 decreased the spore count; however, heat activation was less necessary at pH 3.4, compared at pH 2.8.

• Journal of Microbiology
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• 제43권spc1호
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• pp.93-100
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• 2005

It had long been assumed that a bacterial cell was dead when it was no longer able to grow on routine culture media. We now know that this assumption is simplistic, and that there are many situations where a cell loses culturability but remains viable and potentially able to regrow. This mini-review defines what the 'viable but nonculturable' (VBNC) state is, and illustrates the methods that can be used to show that a bacterial cell is in this physiological state. The diverse environmental factors which induce this state, and the variety of bacteria which have been shown to enter into the VBNC state, are listed. In recent years, a great amount of research has revealed what occurs in cells as they enter and exist in this state, and these studies are also detailed. The ability of cells to resuscitate from the VBNC state and return to an actively metabolizing and culturable form is described, as well as the ability of these cells to retain virulence. Finally, the question of why cells become nonculturable is addressed. It is hoped that this mini-review will encourage researchers to consider this survival state in their studies as an alternative to the conclusion that a lack of culturability indicates the cells they are examining are dead.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.918-922
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• 2001

In a previous study, we have isolated a number of lactobacilli from Korean women, and one of them (KLB46) was identified as Lactobacillus crispatus by 16S rRNA gene sequencing. For the ecological treatment of bacterial vaginosis (BV) cell suspension of L. crispatus KLB46 was instillated into BV patients. L. crispatus KLB46 was found to persist for several days in cell suspension with no nutrients. In this study, in order to assess the influence of starvation on physiological activity, we compared the viability and culturability of KLB46 following suspension in various buffer solutions. A pair of in situ fluorescent dye was used to assess viability (i.e. membrane integrity) and the culturability was examined by plate count assay. A rapid epifluorescence staining method using the LIVE/DEAD Bacterial Viability Kit $(BacLight^{TM})$ was applied to estimate both viable and total counts of bacteria in cell suspension. $BacLight^{TM}$ is composed of two nucleic acid-binding stains ($SYTO\;9^{TM}$ and propidium iodide). $SYTO\;9^{TM}$ penetrates all bacterial membranes and stains the cells green while propidium iodide only penetrates cells with damaged membranes, therefore the combination of the two stains produces red fluorescing cells. Optimal staining conditions for $BacLight^{TM}$ were found to be with 0.0835M $SYTO\;9^{TM}$ and 0.05M propidium iodide for 15 min incubation at room temperature in dark. When cells were microscopically examined during 140 hours of starvation, the culturability decreased markedly while the viability remained relatively constant, which suggests that large fraction of KLB46 cells became viable but non-culturable (VBNC) upon starvation.

• 생명과학회지
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• 제16권3호
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• pp.527-533
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• 2006

벼의 약 및 현미 배양효율과 관련된 DNA marker를 이용하여 인디카형 벼 품종인 'IR 36'의 조직배양 효율을 개선하기 위하여 실험한 결과를 요약하면 다음과 같다. MGRI집단의 약배양에서 식물체분화율이 높은 계통으로 선발된 'MGRI 079'와 'MGRI 036'의 약배양 효율은 각각 19.8%, 19.9%로 가장 높게 나타났다. 'MGRI 079'에 'IR 36'이 여교배되어 양성된 $BC_2F_4$ 100 계통에 대한 marker 검정을 실시하여 선발된 34 계통중 약배양에서 캘러스 형성률이 'IR 36'보다 높은 계통은 30계통이었고, 현미배양에서 'IR 36'보다 식물체 분화율이 높은 계통은 $BC_2F_4-28$ 외 14 계통이었다. $BC_2F_4$ 34계통 중에서 식물체분화능력이 높은 계통으로 선발된 $BC_2F_4-28$은 간장이 'IR 36'보다 큰 편이었으나 출수기와 미립특성은 'IR 36'과 비슷하였다. 'MGRI 036'에 'IR 36'을 반복친으로 여교배하여 양성된 $BC_4F_3$ 50계통의 현미배양을 실시한 결과 'IR 36'보다 식물체 재분화율이 높은 계통은 $BC_4F_3-3$ 외 10 계통이었고, 그중 $BC_4F_3-46$의 식물체 재분화율이 11%로 가장 높게 나타났다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.859-862
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• 2004

An isolate of Pseudomonas putida has been found to aggressively colonize root tips and induce plant resistance to Fusarium wilt. However, P. putida mutants lacking Fe-superoxide dismutase (SOD) or both FeSOD and MnSOD activities are less competitive in root tip colonization. In the current study, the growth of an FeSOD mutant was found to be more sensitive than that of the wild-type or a MnSOD mutant to oxidative stress imposed by paraquat treatment and culturing with the soil fungus Talaromyces flavus, which generates reactive oxygen species. Also, the loss of culturability with an aging stationary-phase culture was greater for a double SOD mutant than an FeSOD mutant, while no reduction in culturability was observed with the wild-type and a MnSOD mutant under the same protracted stationary-phase conditions. Accordingly, it was concluded that FeSOD activity is the major form of SOD in P. putida and plays an essential role in survival under stress conditions when increased oxidative stress is encountered.

• 한국산림과학회지
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• 제79권2호
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• pp.109-114
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• 1990

피나무의 조직배양(組織培養)에 의(依)한 대량증식(大量增殖) 방법(方法)을 확립(確立)하기 위하여, 15년생(年生) 성숙목(成熟木)의 액아(腋芽)를 IS, MS 및 WPM배지(培地)에 배양(培養)하였다. 5수절(水凖)의 BAP농도(濃度)가 검정(檢定)되어, IS와 WPM배지(培地)에서는 BAP 1.0mg/l 첨가(添加)가 줄기 형성(形成)과 생장(生長)을 촉진(促進)한 반면(反面), MS배지(培地)에서는 BP 0.5mg/l 첨가(添加)가 효과적(效果的)이었다. 최적조건(最適條件)은 BAP 1.0mg/l 첨가(添加)의 WPM과 0.5mg/l 첨가(添加)의 MS배지(培地)이었다. 형성(形成)된 줄기는 다경유도(多莖誘導)를 위하여 BAP 0.2mg/l 첨가(添加) 배지(培地)에 다식(多植)하여, 한달안에 약(約) 2배(倍)로 증식(增殖)되었다. 발근(發根)은 고농도(高濃度)의 IBA에서 촉진(促進)되어, IBA 3.0mg/l 첨가(添加)의 1/2MS에서 83.3%의 발근율(發根率)을 얻었다. 재분화(再分化)된 유치물체(幼植物體)는 환경순화(環境馴化)될 수 있었다. 액아배양(腋芽培養)에 의(依)한 줄기 형성(形成)과 생장면(生長面)에서 클론간(間) 변이(變異)를 조사(調査)하기 위하여 수형목(秀型木) 7클론이 검정(檢定)되었다. 조직배양능력(組織培養能力)에 있어서 수형목(秀型木) 클론간(間) 변이(變異)는 Duncan의 다중검정(多重檢定) 5% 유의수준(有意水準)에서 유의성(有意性)이 인정(認定)되었으며, 강원(江原) 12호(號)가 BAP 1.0mg/l 첨가(添加) WPM에서 가장 좋은 반응(反應)을 나타냈다.

• 한국작물학회지
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• 제28권4호
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• pp.425-430
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• 1983

벼의 약배양효율을 증진시키는데 관여하는 요인들의 중요성을 검토하기 위하여 13개의 품종, 4개조합의 F$_1$, 7개조합의 F$_2$를 공시하여 이들의 약을 R$_2$배지에서 배양하였다. 유전자형간 약배양능력의 차이와 함께 약에 대한 저온처리, 배지의 당함량, 배지에 대한 생장조절제 첨가 등의 단독효과 및 유전자형과의 복합효과가 검토될 수 있도록 실험이 수행되었다. 1. 동일한 환경에서 재배된 벼품종 및 교배조합별 F$_1$들의 약배양능력간에는 큰 차이가 인정되었으며 포장에서 재배된 F$_2$들도 교배조합간에 평균 약배양능력이 크게 달랐다. 2. 동일한 교배조합의 F$_2$개체들 간에도 Callus분화율이 큰 변이를 보이고 있어 약배양능력이 유전변이를 보이는 형질임이 확인되었다. 3. 약을 배지에 치상하기 전 8$^{\circ}C$에 5-10일간 온도처리하는 것은 Callus 분화율을 향상시키는데 효과적이었는데 그 효과는 약배양능력이 높은 품종에서 더 컸다. 4. R$_2$배지의 당함량은 3-4%인 것이 Callus분화에 좋았으며 3-5%사이에서는 유전자형과의 복합효과가 인정되지 않았다. 5. R$_2$배지에서는 NAA만을 첨가하는 것이 Callus 분화율을 높이는데 효과적이었으며 약배양능력이 높은 유전자형을 이용했을 때 그 효과가 훨씬 더 컸다. 6. 약배양능력이 높은 유전자형을 선발, 이용하는 것이 약배양에 관여하는 요인들의 효율도 높일 수 있어 그 중요성이 가장 크다고 할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1684-1689
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• 2006

Airborne microorganisms, which are currently termed bioaerosols, have received attention owing to the harmful effects they have on human health. As the concern over airborne microorganisms grows, there also grows an urgent need to study and develop efficient methods for controlling them. In this study, thermal energy using a thermal tube was tested as a control method, mainly against airborne E. coli. For a comparison, B. subtilis var. niger spores were utilized in the experimentation. It was found that the widely known inactivation conditions for microorganisms were not adequate against airborne microorganisms. The experimental results demonstrated the need for extensive studies that should investigate adequate and economic conditions to control against airborne bacteria. In this study, thermal energy exposed by the thermal tube demonstrated an inactivation performance for controlling E. coli bioaerosols.

• 한국초지조사료학회지
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• 제21권2호
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• pp.45-48
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• 2001

In an effort to optimize tissue culture responses of tall fescue, the effects of basic medium and carbon sources on seed culturability and genotypic difference of plant regenerability were investigated. The MS basal medium was superior to $N_{5}$ 6/ and $B_{medium}$ in enhancing callus growth and plant regeneration. To determine the effect of carbon sources on plant regeneration, the seeds were cultured on medium with 30 g/L sucrose and maltose, respectively. Medium supplemented with 30 g/L sucrose resulted in regeneration of shoots from 50% of the calli. The genotypic difference in plant regenerability was obvious among five cultivars of tall fescue tested. \\`KY31\\` and \\`Hokuryo\\` showed to have higher regenerability with the frequency of 33% and 51%, respectively.