• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.995-1004
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• 2017

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

• 환경영향평가
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• 제22권6호
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• pp.725-738
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• 2013

The National Ecosystem Survey in Korea provides information to policy makers for preservation of natural environment and implementation of international agreement. The 1st and 2nd National Ecosystem Survey were carried out between 1986 and 1990, and between 1997 and 2005, respectively. The 3rd National Ecosystem Survey began in 2006 and ended in 2012. In 2013 the pilot survey for the 4th National Ecosystem Survey is ongoing. The 4th National Ecosystem Survey due to the revision of the Natural Environment Conservation Act which has been done every 10 years would change into every five years. It is planned to be conducted from 2014 to 2018. The survey method of the 4th National Ecosystem Survey has been modified to obtain more accurate data for many taxa. The survey for a nocturnal animals will be introduced. In addition, monitoring by setting the grid will get quantitative data seasonally. The vegetation survey will be conducted with a mobile device contained files of aerial image maps including classified vegetation map. National Ecosystem Survey will be improved as follows. First, each survey methods suitable for the purpose should be developed. Second, monitoring methods for obtaining quantitative data should be developed. Finally, the research using the data should be developed in the field of not only ecosystem and biological diversity but also habitat assessment.

• Ocean and Polar Research
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• 제43권1호
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• pp.45-51
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• 2021

Studies on marine zooplankton diversity and ecology are important for understanding marine ecosystem, as well as environmental conservation and fisheries management. DNA metabarcoding is known as a useful tool to reveal and understand diversity among animals, but a comparative evaluation with classical microscopy is still required in order to properly use it for marine zooplankton research. This study compared crustacean mesozooplankton taxa revealed by morphological analysis and metabarcoding of the cytochrome oxidase I (COI). A total of 17 crustacean species were identified by morphological analysis, and 18 species by metabarcoding. Copepods made up the highest proportion of taxa, accounting for more than 50% of the total number of species delineated by both methods. Cladocerans were not found by morphological analysis, whereas amphipods and mysids were not detected by metabarcoding. Unlike morphological analysis, metabarcoding was able to identify decapods down to the species level. There were some discrepancies in copepod species, which could be due to a lack of genetic database, or biases during DNA extraction, amplification, pooling and bioinformatics. Morphological analysis will be useful for ecological studies as it can classify and quantify the life history stages of marine zooplankton that metabarcoding cannot detect. Metabarcoding can be a powerful tool for determining marine zooplankton diversity, if its methods or database are further supplemented.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2006년도 추계학술대회 및 정기총회
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• pp.13-15
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• 2006

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.99.2-99
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• 1999

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.624-630
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• 2008

Terminal restriction fragment length polymorphism (T-RFLP) is a method that has been frequently used to survey the microbial diversity of environmental samples and to monitor changes in microbial communities. T-RFLP is a highly sensitive and reproducible procedure that combines a PCR with a labeled primer, restriction digestion of the amplified DNA, and separation of the terminal restriction fragment (T-RF). The reliable identification of T-RF requires the information of nucleotide sequences as well as the size of T-RF. However, it is difficult to obtain the information of nucleotide sequences because the T-RFs are fragmented and lack a priming site of 3'-end for efficient cloning and sequence analysis. Here, we improved on the T-RFLP method in order to analyze the nucleotide sequences of the distinct T-RFs. The first method is to selectively amplify the portion of T-RF ligated with specific oligonucleotide adapters. In the second method, the termini of T-RFs were tailed with deoxynucleotides using terminal deoxynucleotidyl transferase (TdT) and amplified by a second round of PCR. The major T-RFs generated from reference strains and from T-RFLP profiles of activated sludge samples were efficiently isolated and identified by using two modified T-RFLP methods. These methods are less time consuming and labor-intensive when compared with other methods. The T-RFLP method using TdT has the advantages of being a simple process and having no limit of restriction enzymes. Our results suggest that these methods could be useful tools for the taxonomic interpretation of T-RFs.

• 한국수학사학회지
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• 제21권4호
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• pp.153-168
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• 2008

이 연구는 수학교육에서 문제해결의 중요성에 근거하여 초등 수학 우수아들의 문제 푸는 방법에 대해 조사하였다. 조선시대 수학책인 <산학입문>에서 발췌하여 수정한 문제인 노몬의 넓이 구하는 문제가 주어질 때 84명의 초등 수학 우수아의 반응 및 풀이 과정을 분석하여 분류하였다. 이 중 정답을 얻은 학생들(73.8%)이 사용한 접근 방법은 크게 수치적 접근과 재구성 접근의 두 가지로 나뉜다. 두 접근은 다시 각각 세 가지, 여섯 가지 방법으로 세분할 수 있어 각각의 특징을 학생 사례와 함께 고찰하였다. 그 중 동양 수학사에서 이용된 방법을 포함하여 도형의 재구성을 통한 방법은 특히 주목할 만하다 전체 정답자의 절반에 가까운 수가 수치적 접근을 이용하였음에도 불구하고 동일 문제에 대한 다양한 풀이를 관찰할 수 있었고, 그 분석을 통해 학생들의 사고 특징을 파악할 수 있었다.

• 품질경영학회지
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• 제20권1호
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• pp.101-106
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• 1992

In this paper fuzzy goal programming problems with fuzzy constraints and fuzzy coefficients in both matrix and right hand side of the constraints set are considered. Because of fuzzy coefficients in both members of each constraint ranking methods for fuzzy numbers are considered. An additive model to solve fuzzy goal programming problems is formulated. The diversity of each methods provides a lot of different models of auxiliary linear programming problems from which fuzzy solutions to the fuzzy goal programming problem can be obtained.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1711-1714
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• 2007

Various manufacturing methods are analyzed by using manufacturing metrics to validate which method would be applicable to flexible microelectronics. Among others, Roll-to-Roll method is revealed to inherently have an excessive WIP resulting in long cycle time and limited diversity as well as low equipment efficiency.

• 대한의생명과학회지
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• 제22권4호
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• pp.150-159
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• 2016

Knowledge of the distribution and biodiversity of environmental bacteria and the ecosystem that influences them is crucial for predicting an ecosystem. However, bacterial culture methods can only analyze approximately 0.1% of the existing microorganisms, those that are readily cultured under laboratory conditions. By contrast, next-generation sequencing (NGS) has generally been known to obtain more diverse profiling of bacterial composition. We compared the bacterial communities using both a culture-dependent (MALDI-TOF) and culture-independent (NGS) methods. Environmental specimens were obtained from both freshwater and seawater. Water samples were also analyzed by both pyrosequencing and MiSeq sequencing, in order to select one NGS platform which could analyze comparatively more diverse microbiota. Bacterial distribution analyzed with MALDI-TOF showed no difference between the microbiota of freshwater and seawater, whereas the results analyzed with NGS distinguished between the two. The diversity indexes of MiSeq sequencing were higher than for Pyrosequencing. This indicated that MiSeq sequencing is capable of analyzing a comparatively wider diversity of bacteria. The genus of Flavobacterium and Planktophila were identified as being unique to freshwater, whereas EU801223 and OM43 were found in the seawater. Difference between the bacterial composition of the freshwater and seawater environments was identified by MiSeq sequencing analysis.