• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.2
• /
• pp.144-156
• /
• 2016

Soil is a dynamic biological system, in which it is difficult to determine the composition of microbial communities. Knowledge of microbial diversity and function in soils are limited because of the taxonomic and methodological limitations associated with studying the organisms. In this review, approaches to measure microbial diversity in soil were discussed. Research on soil microbes can be categorized as structural diversity, functional diversity and genetic diversity studies, and these include cultivation based and cultivation independent methods. Cultivation independent technique to evaluate soil structural diversity include different techniques such as Phospholipid Fatty Acids (PLFA) and Fatty Acid Methyl Ester (FAME) analysis. Carbon source utilization pattern of soil microorganisms by Community Level Physiological Profiling (CLPP), catabolic responses by Substrate Induced Respiration technique (SIR) and soil microbial enzyme activities are discussed. Genetic diversity of soil microorganisms using molecular techniques such as 16S rDNA analysis Denaturing Gradient Gel Electrophoresis (DGGE) / Temperature Gradient Gel Electrophoresis (TGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP), Single Strand Conformation Polymorphism (SSCP), Restriction Fragment Length Polymorphism (RFLP) / Amplified Ribosomal DNA Restriction Analysis (ARDRA) and Ribosomal Intergenic Spacer Analysis (RISA) are also discussed. The chapter ends with a final conclusion on the advantages and disadvantages of different techniques and advances in molecular techniques to study the soil microbial diversity.

• Parasites, Hosts and Diseases
• /
• v.35 no.2
• /
• pp.119-126
• /
• 1997

Acanthnmoebn sp. YM-4 is simitar to A. culbertsoni based upon morphological characteristics of trophozoites and cysts. However, based on other characteristics, pathogenicity to mice, in uitro cytotoxicity and isoenzyme patterns, Acanthomoebo sp. YM- 4 was quite different from A. culbertsoni. Restriction fragment length polymorphism (RFLP) analysis of mtDNA is useful in the classification of members belonging to the genus Acanthcmoebn. Therefore, in this study, RFLP analysis of Acnnthcmoeba mtDNAs was accomplished using five restriction enzymes: Hnelll, Hinull, Clcl, Pudl and ScE. Each restriction enzyme produced approximately 3-15 fragments (range: from 0:6 kip to 34.4 kbp) . The mtDNA genome size, calculated by the summation of restriction fragments, averaged 46.4 kbp in Acnnthamoeba sp. YM-4,48.3 kbp in A. culbertsoni and 48.8 kbp in A. polyphaic, respectively. Digested mtDNA fragments of Accnthcmoeba sp. YM-4 contained nine and seven same size fragments, respectively, from a total of 67 and 69 fragments observed in A. culbertsoni and A. polyphcgn. An estimate of the genetic divergence was 10.1% between Acanthamoebc sp. YM-4 and A. culbertsoni, and 9.9% between Acanthamoebn sp. YM-4 and A. polyphcga.

• Korean Journal of Environment and Ecology
• /
• v.29 no.4
• /
• pp.636-644
• /
• 2015

In this paper, we examined factors that affect the success of a policy on trekking time restriction using questionnaire survey data collected from the visitors of seven national parks where the trekking time restriction policy is in force as of 2014. Results suggest that the trekking time restriction policy has been successfully publicized. In total, 60.7% of the survey respondents were aware of trekking time restrictions in the national parks they were visiting. Using exploratory factor analysis, we identified three latent factors (visitors' careless trekking, park rangers' insufficient management and visitors' unpreparedness) that the visitors perceived the causes of trekking accidents in the national parks. Multiple regression analysis on the three extracted factors and respondents' socioeconomic status shows that the respondents who read information signs in national parks and who judged visitors' careless trekking and visitors' unpreparedness as the causes of trekking accidents tended to agree more with restricting trekking time. These results indicate that visitors who do not agree with the trekking time restriction tend to attribute trekking accidents in national parks not to individual visitors, suggesting that educating visitors is more effective in preventing trekking accidents in national parks than installing and maintaining safety facilities by park rangers.

• Microbiology and Biotechnology Letters
• /
• v.40 no.4
• /
• pp.389-395
• /
• 2012

T-RFLP (terminal restriction fragment length polymorphism) analysis, one of the most highly adopted culture-independent microbial community analysis methods, was applied to evaluate the colonization of probiotics in experimental animal gut. Lactic acid bacteria that exhibited cinnamoyl esterase activity were isolated from Korean fermented vegetables and identified by 16S ribosomal RNA sequence analysis. Lactobacillus plantarum KK3, which demonstrated high chlorogenic acid hydrolysis by cinnamoyl esterase activity, and acid/bile salt resistances, was cultured, freeze-dried, and fed to mice and the microbiota in their feces were monitored by T-RFLP analysis. The T-RF of L. plantarum was detected in the feces of mice after the start of administration and lasted at least 31 days after the initial 7 day feeding. T-RFLP analysis was considered a useful tool to evaluate the gut colonization of probiotic L. plantarum. In order to prove that L. plantarum was from viable cells, we reisolated L. plantarum in the feces using cinnamoyl esterase activity media as the screening step. The colonization of L. plantarum KK3 in the mouse gut was confirmed by this research.

• BMB Reports
• /
• v.34 no.2
• /
• pp.114-117
• /
• 2001

Cervi Parvum Cornu is widely used as a hemopoietic, tonifying, growth-promoting, cardiotonic, and immuno-modulating agent in Korea. In order to develop the quality control method of Cervi Parvum Cornu by the identification of the biological source or origin, the molecular approach was applied using PCR (polymerase chain reaction) and PCR-RFLF (PCR-restriction fragment length polymorphism) analysis. In the PCR analysis of the mitochondrial 12S rRNA gene and cytochrome b gene regions, no distinctive DNA bands from Cervidae (deer) antlers and Rangifer (reindeer) antlers were observed. However, when the amplified products in the mitochondrial cytochrome b gene region were subjected to restriction digestion with TaqI, Cervidae antlers showed an undigested state of 380 by band, differently from two bands of 230 by and 1S0 by from Rangifer antlers. Based on this finding, the base sequences of amplified PCR products in the range of mitochondria) cytochrome b gene from Cervidae antlers and Rangifer antlers were determined and subjected to restriction analysis by various endonucleases. The results showed that antlers from Rangifer species could be simply discriminated with other antlers from 8 Cervidae species (Chinese deer, Russian deer, Hong Kong deer, New Zealand deer, Kazakhstan deer, elk, red deer and Sika deer) by PCR-RFLP analysis using AtuI, HaeIII, HpaII or Sau3AI(MboI) as well as TaqI in the range of the mitochondrial cytochrome b gene.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.1
• /
• pp.176-181
• /
• 2002

In order to isolate and identify Bifidobacterium spp. that originated in Korea, feces were sampled from healthy Korean adults and children living in three villages, the first having a history of longevity and the other two where the diet did not include fermented milk or any pharmaceutical preparations. Through the use of Gram staining and microscopic examination for cell morphology, 23 bacterial strains presumed to be the Bifidobacterium genus were isolated from the feces of 13 out of a total of 59 Korean people. To identify the Bifidobacterium strains at the genus level, these bacteria were then analyzed by TLC and the fructose-6-phosphate phosphoketolase (F6PPK) test. The result showed that 22 of the isolated strains were confirmed to be members of the genus Bifidobacterium. All of these bifidobacteria were also identified as Bifidobacterium spp. by the fermentation test. Using a RFLP analysis, an attempt was made to identify the Bifidobacterium spp. that had been isolated from both Korean adults and children. In a genomic Southern blot analysis after digestion with two restriction enzymes (EcoRI, HindIII), all of the 14 randomly selected Korean isolates showed patterns identical to those of three different B. longum species. Another restriction enzyme, CfoI (4-bp recognition enzyme), was then used to identify the strain. Interestingly, all the Korean isolates were identified as B. longum ATCC 15708, indicating that a RFLP analysis was effective for identifying Bifidobacterium spp. at both the strain and species levels.

• The Journal of the Korean Society for Microbiology
• /
• v.34 no.6
• /
• pp.561-571
• /
• 1999

Diagnosis of mycobacterial infection is dependent upon the isolation and identification of causative agents. The procedures involved are time consuming and technically demanding. To improve the laborious identification process mycobacterial systematics supported by gene analysis is feasible, being particularly useful for slowly growing or uncultivable mycobacteria. To complement genetic analysis for the differentiation and identification of mycobacterial species, an alternative marker gene, rpoB encoding the ${\beta}$ subunit of RNA polymerase, was investigated. rpoB DNAs (342 bp) were amplified from 52 reference strains of mycobacteria including Mycobacterium tuberculosis H37Rv (ATCC 27294) and clinical isolates by the PCR. The nucleotide sequences were directly determined (306 bp) and aligned using the multiple alignment algorithm in the MegAlign package (DNASTAR) and MEGA program. A phylogenetic tree was constructed with a neighborhood joining method. Comparative sequence analysis of rpoB DNA provided the basis for species differentiation. By being grouped into species-specific clusters with low sequence divergence among strains belonging to same species, all the clinical isolates could be easily identified. Furthermore RFLP analysis enabled rapid identification of clinical isolates.

• Korean Journal Plant Pathology
• /
• v.14 no.4
• /
• pp.308-313
• /
• 1998

Reverse transcription and polymerase chain reaction (RT-PCR) techiniques were used to identification and differentiation of cucumber mosaic virus isolated from Forsythia koreana (CMV-Fk). RT-PCT used by two set of 20-mer primers one was CMV-common primers and another was CMV subgroup I-specific primers designed in a conserved region of the 3' end of CMV RNA3, amplified about 490 bp and 200 bp DNA fragments from CMV-Fk, respectively. CMV could be detected by RT-PCR at a dilution as low as 10-4 in forsythia crude sap extracts. Restriction enzyme analysis of RT-PCR products using EcoRI and MspI showed that CMV-Fk belonged to CMV subgroup I. But, analysis of RNA fingerprinting by arbitrarily primed polymerase chain reaction (RAP-PCR) showed heterogeneity of RNA3 between CMV-Fk and CMV-Y as a member of subgroup I.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.8 s.173
• /
• pp.108-117
• /
• 2005

In modern industrial society, many kinds of valves have been used to control fluid flow. For the optimization of a ball valve, a quarter of spherical ball was modeled and evaluated. However, there is a difficulty in the application of the optimization technique because of the complexity of the fluid and the restriction of analysis. Therefore, in this study, it is performed to evaluate the stability of an initial model using FEM(Finite Element Method) and CFD. In addition, a shape optimization design of the valve is accomplished using an orthogonal arrangement and characteristic functions. From the result, a new design method is represented that could overcome the time and space restriction in structural design, such as the divided ball valve with less experiment.

• The Plant Pathology Journal
• /
• v.26 no.3
• /
• pp.289-292
• /
• 2010

This study used a modified cetyltrimethylammonium bromide (CTAB) method to efficiently extract DNA from the plant pathogenic fungus Cercospora sojina. Total DNA yield obtained by this method was approximately 1 mg/g of mycelia (fresh weight), and the mean ratio of A260/A280 and A260/A230 were 2.04 and 2.1, respectively. The results of random amplified polymorphic DNA (RAPD) analysis, digestion with restriction enzymes, and Southern hybridization indicated that polysaccharides were effectively removed by this method, and the resulting DNA was sufficient for use in subsequent molecular analysis.