• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.325-330
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• 1998

On the basis of the fact that the pycnidiospore of Botryosphaeria dothidea, the causal fungus of apple white rot is a typical water borne spore, a method for quantitative analysis of pycnidiospore dispersal from the warts produced on the diseased apple tree stem was developed. The warts on which cracks developed either on or around them were cut off at the base, and shaked in the water for 4hours at 2$0^{\circ}C$, in which condition the maximum number of spores were released. The volume of shaking solution was calculated as 1 ml per one wart. At the end of shaking, Trio, a household detergent was added to the shaking solution to the concentration of 0.1%, and shaked for additional 10 minutes at 35$^{\circ}C$ to take off the spores attached on the glass ware. One milliliter of the spore suspension thus prepared were passed through transparent membrane filter (pore size : 3.0 ${\mu}{\textrm}{m}$), and the spores attached on the filter were counted under a microscope ($\times$200) after staining them with lactophenol supplemented with aniline blue. The results thus obtained were statistically consistent when at least 30 warts were used simultaneously in single shaking. This method can be applicable in the elucidation of ecology of sporulation and spore dispersal, and also in the screening of the sporulation inhibitor which can be used in the control of the disease by reducing the inoculum density.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.507-513
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• 2017

Bacillus subtilis spores can be used for protein display to engineer protein properties. This method overcomes viability and protein-folding concerns associated with traditional protein display methods. Spores remain viable under extreme conditions and the genotype/phenotype connection remains intact. In addition, the natural sporulation process eliminates protein-folding concerns that are coupled to the target protein traveling through cell membranes. Furthermore, ATP-dependent chaperones are present to assist in protein folding. CotA was optimized as a whole-cell biocatalyst immobilized in an inert matrix of the spore. In general, proteins that are immobilized have advantages in biocatalysis. For example, the protein can be easily removed from the reaction and it is more stable. The aim is to improve the pH stability using spore display. The maximum activity of CotA is between pH 4 and 5 for the substrate ABTS (ABTS = diammonium 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate). However, the activity dramatically decreases at pH 4. The activity is not significantly altered at pH 5. A library of approximately 3,000 clones was screened. A E498G variant was identified to have a half-life of inactivation ($t_{1/2}$) at pH 4 that was 24.8 times greater compared with wt-CotA. In a previous investigation, a CotA library was screened for organic solvent resistance and a T480A mutant was found. Consequently, T480A/E498G-CotA was constructed and the $t_{1/2}$ was 62.1 times greater than wt-CotA. Finally, E498G-CotA and T480A/E498G-CotA yielded 3.7- and 5.3-fold more product than did wt-CotA after recycling the biocatalyst seven times over 42 h.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1020-1026
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• 2007

The control of pathogenic microorganisms is important issue in human environments, especially in surface area. However, surface disinfection has not been fully researched. In this study, the surface disinfection under UV irradiation was performed to investigate the quantitative kinetics for Bacillus subtilis spore inactivation in several experimental conditions, such as light intensity, temperature and surface roughness. This study reports that UV light would apparently inactivates the microorganisms and the required IT value for 2 log (99%) Bacillus subtilis spore inactivation was found to be 14.5 $mJ/cm^2$ in plain surface, as predicted by the Delayed Chick-Watson model. When UV was irradiated, there were no significant temperature effects. However, the experimental result shows that the more increased IT values are required at larger surface roughness.

• Journal of fish pathology
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• v.9 no.1
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• pp.15-19
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• 1996

The mature spores of present Myxobolus sp. was ovoid in front view with no distinct redges of folds, lemon-shaped in side view with a straight sutural ridge. Spore valves showed symmetrical and smooth. Spores were 9 to $12{\mu}m$ (Mean=$10.4{\pm}0.7$, n=50)in length, 6 to $9{\mu}m$ (Mean=$7.7{\pm}0.6$, n=50) in width and 5.0 to $7.5{\mu}m$ (Mean=6.2, n=7) in thickness. Two polar capsules of spore were pyriform in shape, equal or mearly equal in size, 3 to $6{\mu}m$(Mean=$4.6{\pm}0.6$, n=50) in length, 2 to $3{\mu}m$(Mean=$2.2{\pm}0.3$, n=50) in width, Polar filaments of spore were composed with six to seven coils within capsules. Extended polar filaments were 55 to $135{\mu}m$ (Mean=78.7, n=50)in length. The shape and measurements of the present Mysobolus sp. spores were very similar with the spore of M. cyprinicola Reuss, 1906.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.246-246
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• 2017

Salinity inhibits plant growth and restricts the efficiency of arbuscular mycorrhizal fungi. The selective uptake of nutrients from the soil and their effective transport to host roots make it essential for plant growth and development under salt stress. AMF spore associated bacteria shown to improve mycorrhizal efficiency under stress. Thus, this study aimed to understand the co-inoculation efficiency of AMF and SAB on maize growth and ion homeostasis under salt stress. Two AMF strains and one SAB were inoculated with maize either alone or in combination with one another. The results of our study showed that AMF and SAB co-inoculation significantly improved dry weight and nutrient uptake of maize under salt stress. Co-inoculation significantly reduced proline accumulation in shoots and Na+ accumulation in roots. Co-inoculation treatment also exhibited the high K+/Na+ ratios in roots at 25 mM NaCl. Mycorrhizal colonization showed positive influence for regulation of ZmAKT2, ZmSOS1 and ZmSKOR gene expressions, contributing to K+ and Na+ ion homeostasis. CLSM view showed that SAB were able move and localize into inter and intra cellular spaces of maize roots. In addition, CLSM view of AMF spores showed that gfp-tagged SAB also associated on the spore outer hyaline layer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.539-543
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• 1992

This study was carried out to investigate the antimutagenic affect of crude and heated comfrey extract on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), benzo${(\alpha)}$pyrene (B${(\alpha)}$P) and 3-amino-1, 4-dimethyl-5H-pyri-do [4,3-b] indole (Trp-P-1). In spore rec-assay using Bacillus subtilis $H17(rec^+)$ and $M45(rec^-),$ crude comfrey extract showed strong antimutagenic effects on MNNG in the concentration of $40{\mu}l/disc$(p<0.01). In the Ames test using Salmonella typhimurium TA98 and TA100, the crude comfrey extract suppressed about 43% and 52% in the mutagenesis induced by $B{(\alpha)}P.$ However, the heated comfrey extract strongly suppressed about 75% and 76% in the mutagenesis in Salmonella typhimurium TA98 and TA100 induced by Trp-P-1(p<0.01).

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.38-50
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• 1993

Four plant (Sorghum bicolor, Cassia mimosoides var. nomame, Sesamum indicum and Glycine soja) were cultivated at the pots including the soils containing arbuscular mycorrhizal fungi and were also investigated with the colonizations and productions of arbuscular mycorrhizal fungi. Whereas the colonizations of arbuscular mycorrhizal fungi continuosly increased on the roots until 50 days, the productions of arbuscular mycorrhizal fungal spores were fluctuated with the terms of 30 days after inoculated. This indicated that the colonizations on the roots were not correlated with productions of arbuscular mycorrhizal fungal spores. Also, the various soils collected were applied to this technique by using pot cultures. Out of 82 various soils collected, the spore productions of arbuscular mycorrhiaze were observed only from 42 soils. The spores cultured under artificial conditions were identified to 15 species with four genera. The spore productions of arbuscular mycorrhizal fungi using this technique would be considered to be related to the soil pH: The spore productions were found in the low pH for the species of Acaulospora and Glomus, the those near pH 7.6 for the species of some Glomus, Scutellospora and Gigaspora.

• The Korean Journal of Quaternary Research
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• v.15 no.2
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• pp.83-91
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• 2001

The environmental change during the upper Holocene was restored at Kimpo alluvial plain on the left bank of Han-river near the Yellow Sea according to the results of pollen analysis and carbon dating, based on the sea-level change from Ilsan area. Pollenzone I (5.8~7.0 m.a.s.l.) was the period of AP-dominance, including mostly Alnus. Study area was under the lagoon or swamp environment influenced by Flandrian transgression during 5,000~3,200 BP. Pollenzone II (7.0~7.4 m.a.s.l.) was the period of Spore & NAP-dominance. It represents that the vegetational environment was changed to drier condition by falling underwater surface caused by sea-level regression, and influenced by human activity during 3,200~2,300 BP. Subzone I a represented the characteristics of the climax of transgression. During subzone I b, herbs with the dominant Alnus were increased gradually, and it was correlated to the stagnation of high sea-level. Subzone II a was the dominant period of Spore by the gradual falling of sea-level. After that, the study area in swamp was emerged to the lowland by the fallen sea-level and herbs, especially Gramineae increased suddenly during Subzone II b. The sudden increase of NAP such as Artemisia, Chenopodiaceae and Umbelliferae with Gramineae during this period indicates the beginning of agriculture at this study area.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.193-199
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• 2006

Halotolerant spore-forming Gram-positive bacteria were isolated from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides. The different isolates were characterized genetically using an amplified ribosomal DNA restriction analysis (ARDRA), and phenotypically based on their colonial morphology, physiology, and nutritional requirements. Three different 16S rRNA gene-based genotypes were observed at a 100% similarity using the enzymes HinfI, MspI, and RsaI, and the phenotypic results also followed the ARDRA groupings. Selected strains, representing the different ARDRA groups, were analyzed by 16S rDNA sequencing, and members of the genera Halobaeillus, Virgibacillus, and Oceanobacillus were found. Two isolates showed low 16S rDNA sequence similarities with the closest related species of Halobacillus, indicating the presence of new species among the isolates. The majority of the strains isolated in this study seemed to belong to the species O. iheyensis and were compared using an AP-PCR to determine whether they had a clonal origin or not. Different patterns allowed the grouping of the strains according to Pearson's coefficient, and the resulting dendrogram revealed the formation of two main clusters, denoted as A and B. All the strains isolated from the soil were grouped into cluster A, whereas cluster B was exclusively composed of the strains associated with the B. portulacoides roots. This is the first report on the isolation and characterization of halotolerant spore-forming Gram-positive bacteria that coexist with B. portulacoides. As such, these new strains may be a potential source for the discovery of bioactive compounds with industrial value.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.539-547
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• 2009

This study was conducted to investigate the arbuscular mycorrhizal fungal biodiversity, spore density and root colonization in relation to site ages at expressway cut-slopes in Korea. Stabilization of exposed surface involved soil amendments and spraying seed mixture of turf grasses and/or nitrogen-fixing shrub species. Eighteen sites were selected with varying ages (2 to 16 years). Soil samples collected in October from each site were analyzed for fungal diversity and spore counts. Fine root samples from the plants were assayed for fungal colonization. Of the total 37 plants inspected in the sites, 26 species had endomycorrhizal colonization with an average root colonization rate of 18%, and with a range from 1 to 67%. The average endomycorrhizal colonization rate of initially introduced Festuca arundinacea which became the most dominant grass in later stage showed 22.8%, while that of Lespedeza bicolor which became the most dominant woody species were 21.6%. Naturally-invading Robinia pseudoacacia showed higher colonization rate in the old sites. Although site age did not show significant effects on fungal diversity, the root colonization rates of initially introduced plants decreased with the site aging, while those of invading plants increased with aging of the sites. The soil chemical properties, pH, N, and P contents, were negatively correlated with spore density, root colonization and endomycorrhizal species diversity. A total of forty arbuscular mycorrhizal fungal species in seven genera were identified. Of the 40 species, Acaulospora lacunosa, Glomus aggregatum, Glomus constrictum, Scutellospora erythropa, and Acaulospora spinosa were the five most dominant species in the decreasing order.