• 한국잠사곤충학회지
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• 제36권1호
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• pp.62-68
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• 1994

뽕나무 추기벌채 후 피해가 큰 가지썩음 증상에서 빙핵활성세균의 분리, 생물검정 및 동정과 밀도를 조사하여 본 결과 1. 총 36개의 분리세균 중 -1$0^{\circ}C$ 이상 온도에서 동결이 되는 세균은 12개였으며, -5$^{\circ}C$ 이상의 온도에서는 2개균주였다. 2. 공시세균의 생물검정에 있어서 토마토와 옥수수에서는 -1$0^{\circ}C$ 이상의 동결균주에서는 일정한 경향을 볼 수 없었으나 뽕나무에서는 -5$^{\circ}C$ 이상에서 동결이 되는 세균에서만 육안으로 확실한 동상해피해를 볼 수 있었다. 3. 뽕나무, 옥수수, 토마토유묘에 피해를 주며 -5$^{\circ}C$ 이상에서 영핵활성이 있는 균주 SE9316, SE9338을 동정해 본 결과 gram음성, 간상형, 운동성이 있고 극모를 가지고 호기성균인 Pseudomonas syringae로 동정되었다. 4. 5cm, 10cm 이병뽕나무가지에서 Pseudomonas 속 영핵활성세균의 밀도는 2월과 4월이 가장 높았고, 5월에는 감소하는 경향이었으며 병반에서 멀어질수록 밀도는 감소하였다. 또한 그 밀도는 105cfu/g 이상으로서 동상해를 유발시키기에 충분한 밀도였다.

• 한국영양학회:학술대회논문집
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• 한국영양학회 2003년도 연합학술대회
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• pp.219.1-219.1
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• 2003

• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1184-1192
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• 2011

A bacterial isolate (strain JS-2) characterized as Bacillus sp. was challenged with high concentrations of toxic selenite ions. The microbe was found to transform the toxic, soluble, colorless selenite (${SeO_3}^{2-}$) oxyions to nontoxic, insoluble, red elemental selenium ($Se^0$). This process of biotransformation was accompanied by cytoplasmic and surface accumulation of electron dense selenium ($Se^0$) granules, as revealed in electron micrographs. The cells grown in the presence of selenite oxyions secreted large quantities of extracellular polymeric substances (EPS). There were quantitative and qualitative differences in the cell wall fatty acids of the culture grown in the presence of selenite ions. The relative percentage of total saturated fatty acid and cyclic fatty acid increased significantly, whereas the amount of total unsaturated fatty acids decreased when the cells were exposed to selenite stress. All these physiological adaptive responses evidently indicate a potentially important role of cell wall fatty acids and extracellular polymeric substances in determining bacterial adaptation towards selenite-induced toxicity, which thereby explains the remarkable competitiveness and ability of this microbe to survive the environmental stress.

• 한국미생물·생명공학회지
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• 제52권2호
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• pp.211-214
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• 2024

This study aimed to confirm the induction of resistance to other drug classes by treating Mycobacterium abscessus with moxifloxacin, a fluoroquinolone used for treating nontuberculous mycobacteria infection, and to obtain genetic data for improving treatment. The reads were assembled and analyzed using reference strain sequence data, and the whole-genome and transcriptome sequences of four strains (MD2, MD4, MD6, and MD8) were reported. Antibiotic resistance was not induced by moxifloxacin treatment; however, transcriptomic analysis revealed that the expression of genes responding to stress was upregulated.

• 한국해양생명과학회지
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• 제4권1호
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• pp.22-28
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• 2019

The bacterial diversity of an Antarctic hard coral, Errina fissurata, was examined by isolating bacterial colonies from crushed coral tissue and by sequencing their 16S rRNA gene. From the analyzed results, the bacteria were classified as Actinobacteria (56%), Firmicutes (35%) and Proteobacteria (9%). The thirty-four isolates were cultured in liquid media at different temperatures and their growth was assessed over time. The majority of the isolates displayed their highest growth rate at 25℃ during the first three days of cultivation, even though the coral was from a cold environment. Nevertheless, strains showing their highest growth rate at low temperatures (15℃ and 4℃) were also found. This study reports the composition of an Antarctic hard coral-associated culturable bacterial community and their growth behavior at different temperatures.

• Journal of Microbiology
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• 제41권3호
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• pp.252-258
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• 2003

The carbon utilizations of Bacillus species and Pythium species were investigated by using a Biolog$^{(R)}$ microplate assay to determine if there are differences in the carbon utilizations of selected strains of these species. It may be possible to afford a competitive advantage to bacterial biological control agents by providing them with a substrate that they can readily use as a carbon source, for example, in a seed coating formulation. Microplates, identified as SFP, SFN and YT were used to identify spore-forming bacteria, nonspore-forming bacteria, and yeast, respectively. Bacterial and mycelial suspensions were adjusted to turbidities of 0.10 to 0.11 at 600 nm. One hundred microliters of each of the bacterial and mycelial suspension were inoculated into each well of each of the three types of microplates. L-arabinose, D-galactose, D-melezitose and D-melibiose of the 147 carbohydrates tested were found to be utilized only by bacteria, and not by Pythium species, by Biolog$^{(R)}$ microplate assay, and this was confirmed by traditional shake flask culture. Thus, it indicated that the Biolog$^{(R)}$ microplate assay could be readily used to search for specific carbon sources that could be utilized to increase the abilities of bacterial biological control agents to adapt to contrived environments.

• 상하수도학회지
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• 제24권6호
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• pp.661-674
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• 2010

Bacterial biomass and its activity were measured in two kinds of granular activated carbon (GAC), the experimental and existing biofiltration system in a drinking water plant. The bacterial biomass was around 210 to 250 nmol P/g WW with phospholipid concentration at acclimation of ozonation treatment. The phospholipid biomass shows more or less a declining gradient along filter depth and no clear seasonality in its values. On the other hand, the microbial activity of [$^3H$]-thymidine and [$^{14}C$]-acetate incorporation within cells increased significantly along the filter depth, showing the difference of three fold between the upper and bottom layer. These factors support the different microbial composition or metabolic activity along the depth of GAC column. Turnover rates, the rate of bacterial biomass and production of biofilm, ranged from 0.26 /hr to 0.37 /hr, indicating a highly rapid recovery itself at amature state. In the non-ozonation treatment, the bacterial biomass was lower than in the ozonation and biological activity also declined towards the filter depth. The biomass levels during cessation of ozonation in the existing GAC filters were 68% of the actively ozonated state.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.114-117
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• 2012

The biological control efficacy of a greenhouse soil bacterial mixture of Lactobacillus farraginis, Bacillus cereus, and Bacillus thuringiensis strains with antinematode activity was evaluated against the root-knot nematode Meloidogyne incognita. Two control groups planted in soil drenched with sterile distilled water or treated with the broad-spectrum carbamate pesticide carbofuran were used for comparison. The results suggest that the bacterial mixture is effective as a biocontrol agent against the root-knot nematode.

• Mycobiology
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• 제28권3호
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• pp.123-126
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• 2000

Sodium hypochlorite alkaline was tested against Pseudomonas tolaasii causing bacterial blotch on cultivated oyster mushroom (Pleurotus ostreatus). The minimum inhibitory concentration of sodium hypochlorite against P. tolaasii contained active chlorine (AC) at 1.4 mg/l on plate assay. The highest cultivation yield was obtained from the treatment of AC 5.7 mg/l. Treatment of sodium hypochlorite at the rate of higher than AC 11.4 mg/l resulted in reduced yields at the harvest. However, the population of total bacteria on the bed surface treated with AC 5.7 mg/l of sodium hypochlorite was maintained to some extent. Inhibitory concentration against total bacteria on the bed surface was over AC 22.8 mg/l. Mushroom mycelium was damaged and its growth strongly inhibited at the concentration of AC 200 mg/l. Mushroom caps showed yellowish symptom by chemical injury by treatments of AC 74.1 mg/l or higher. Sporocarps infected by P. tolaasii were irrevocable at any concentration of sodium hypochlorite. Routine watering with AC 5.7 mg/l from mushroom initiation to the end of picking resulted in reduced bacterial blotch incidence of 40% and 86% at two mushroom farms. The treatment resulted in higher quality mushroom production compared to that conventionally watered with tap water alone.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 추계학술대회 논문집
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• pp.274-274
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• 2008