• Title/Summary/Keyword: Metagenomics

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SoEM: a novel PCR-free biodiversity assessment method based on small-organelles enriched metagenomics

  • Jo, Jihoon;Lee, Hyun-Gwan;Kim, Kwang Young;Park, Chungoo
    • ALGAE
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    • v.34 no.1
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    • pp.57-70
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    • 2019
  • DNA metabarcoding is currently used for large-scale taxonomic identification to understand the community composition in various marine ecosystems. However, before being widely used in this emerging field, this experimental and analytic approach still has several technical challenges to overcome, such as polymerase chain reaction (PCR) bias, and lack of well-established metabarcoding markers, a task which is difficult but not impossible to achieve. In this study, we present an adapted PCR-free small-organelles enriched metagenomics (SoEM) method for marine biodiversity assessment. To avoid PCR bias and random artefacts, we extracted target DNA sequences without PCR amplification from marine environmental samples enriched with small organelles including mitochondria and plastids because their genome sequences provide a valuable source of molecular markers for phylogenetic analysis. To experimentally enrich small organelles, we performed subcellular fractionation using modified differential centrifugation for marine environmental DNA samples. To validate our SoEM method, two marine environmental samples from the coastal waters were tested the taxonomic capturing capacity against that of traditional DNA metabarcoding method. Results showed that, regardless of taxonomic levels, at least 3-fold greater numbers of taxa were identified in our SoEM method, compared to those identified by the conventional multi-locus DNA metabarcoding method. The SoEM method is thus effective and accurate for identifying taxonomic diversity and presents a useful alternative approach for evaluating biodiversity in the marine environment.

Metagenomic Analysis of Chicken Gut Microbiota for Improving Metabolism and Health of Chickens - A Review

  • Choi, Ki Young;Lee, Tae Kwon;Sul, Woo Jun
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.9
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    • pp.1217-1225
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    • 2015
  • Chicken is a major food source for humans, hence it is important to understand the mechanisms involved in nutrient absorption in chicken. In the gastrointestinal tract (GIT), the microbiota plays a central role in enhancing nutrient absorption and strengthening the immune system, thereby affecting both growth and health of chicken. There is little information on the diversity and functions of chicken GIT microbiota, its impact on the host, and the interactions between the microbiota and host. Here, we review the recent metagenomic strategies to analyze the chicken GIT microbiota composition and its functions related to improving metabolism and health. We summarize methodology of metagenomics in order to obtain bacterial taxonomy and functional inferences of the GIT microbiota and suggest a set of indicator genes for monitoring and manipulating the microbiota to promote host health in future.

The Principles and Applications of High-Throughput Sequencing Technologies

  • Jun-Yeong Lee
    • Development and Reproduction
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    • v.27 no.1
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    • pp.9-24
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    • 2023
  • The advancement in high-throughput sequencing (HTS) technology has revolutionized the field of biology, including genomics, epigenomics, transcriptomics, and metagenomics. This technology has become a crucial tool in many areas of research, allowing scientists to generate vast amounts of genetic data at a much faster pace than traditional methods. With this increased speed and scale of data generation, researchers can now address critical questions and gain new insights into the inner workings of living organisms, as well as the underlying causes of various diseases. Although the first HTS technology have been introduced about two decades ago, it can still be challenging for those new to the field to understand and use effectively. This review aims to provide a comprehensive overview of commonly used HTS technologies these days and their applications in terms of genome sequencing, transcriptome, DNA methylation, DNA-protein interaction, chromatin accessibility, three-dimensional genome organization, and microbiome.

Evaluating the Prevalence of Foodborne Pathogens in Livestock Using Metagenomics Approach

  • Kim, Hyeri;Cho, Jin Ho;Song, Minho;Cho, Jae Hyoung;Kim, Sheena;Kim, Eun Sol;Keum, Gi Beom;Kim, Hyeun Bum;Lee, Ju-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.31 no.12
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    • pp.1701-1708
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    • 2021
  • Food safety is the most important global health issue due to foodborne pathogens after consumption of contaminated food. Foodborne bacteria such as Escherichia coli, Salmonella enterica, Staphylococcus aureus, Campylobacter spp., Bacillus cereus, Vibrio spp., Yersinia enterocolitica and Clostridium perfringens are leading causes of the majority of foodborne illnesses and deaths. These foodborne pathogens often come from the livestock feces, thus, we analyzed fecal microbial communities of three different livestock species to investigate the prevalence of foodborne pathogens in livestock feces using metagenomics analysis. Our data showed that alpha diversities of microbial communities were different according to livestock species. The microbial diversity of cattle feces was higher than that of chicken or pig feces. Moreover, microbial communities were significantly different among these three livestock species (cattle, chicken, and pig). At the genus level, Staphylococcus and Clostridium were found in all livestock feces, with chicken feces having higher relative abundances of Staphylococcus and Clostridium than cattle and pig feces. Genera Bacillus, Campylobacter, and Vibrio were detected in cattle feces. Chicken samples contained Bacillus, Listeria, and Salmonella with low relative abundance. Other genera such as Corynebacterium, Streptococcus, Neisseria, Helicobacter, Enterobacter, Klebsiella, and Pseudomonas known to be opportunistic pathogens were also detected in cattle, chicken, and pig feces. Results of this study might be useful for controlling the spread of foodborne pathogens in farm environments known to provide natural sources of these microorganisms.

Epibionts associated with floating Sargassum horneri in the Korea Strait

  • Kim, Hye Mi;Jo, Jihoon;Park, Chungoo;Choi, Byoung-Ju;Lee, Hyun-Gwan;Kim, Kwang Young
    • ALGAE
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    • v.34 no.4
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    • pp.303-313
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    • 2019
  • Floating seaweed rafts are a surface-pelagic habitat that serve as substrates for benthic flora and fauna. Since 2008, Sargassum horneri clumps have periodically invaded the Korea Strait. In this study, the polymerase chain reaction-free small-organelles enriched metagenomics method was adopted to identify the species of epibiotic eukaryotes present in floating S. horneri fronds. A total of 185 species were identified, of which about 63% were previously undetected or unreported in Korean waters. The rafts harbored a diverse assemblage of eukaryotic species, including 39 Alveolata, 4 Archaeplastida, 95 Opisthokonts, 4 Rhizaria, and 43 Stramenopiles. Of these 185 taxa, 48 species were found at both Sargassum rafts collection stations and included 24 Stramenopiles, 17 Alveolata, and 7 Opisthokonts. Among these, the highest proportion (50%) of species was photo-autotrophic in basic trophic modes, while the proportion of phagotrophic, osmo- or saprotrophic, and parasitic modes were 43.8%, 4.2%, and 2.1%, respectively. This study demonstrates the contribution of floating Sargassum rafts as dispersal vectors that facilitate the spread of alien species.