Temporal changes of geochemistry and microbial community in low and intermediate level waste (LILW) repository, South Korea

2019 ◽  
Vol 128 ◽  
pp. 309-317 ◽  
Author(s):  
Jinmo Ahn ◽  
Won-Seok Kim ◽  
Jin-Beak Park ◽  
Arokiasamy J. Francis ◽  
Wooyong Um
2018 ◽  
Vol 28 (2) ◽  
pp. 65-77 ◽  
Author(s):  
Jiyoung Lee ◽  
Jae-Hyun Lim ◽  
Junhyung Park ◽  
Il-Nam Kim

Microbial communities play an essential role in marine biogeochemical cycles. Physical and biogeochemical changes in Jinhae Bay, the most anthropogenically eutrophied bay on the coasts of South Korea, are well described, but less is known about the associated changes in microbial communities. Temporal and vertical variation in microbial communities at three depths (surface, middle, and bottom) at seven time points (June to December) at the J1 sampling site were investigated on the MiSeq platform based on the 16S rRNA gene. Overall, the microbial community was dominated by Proteobacteria, Cyanobacteria, and Bacteroidetes from June to November, whereas Firmicutes were dominant in December, especially in the middle and bottom layers. The results indicate that the microbial community composition strongly varied with temporal changes in the physicochemical water properties. Moreover, the community composition differed markedly between the surface and middle layers and the bottom layer in the summer, when the water column was strongly stratified and bottom water hypoxia developed. A redundancy analysis suggested a significant correlation between physicochemical variables (i.e., temperature, salinity, and oxygen concentration) and microbial community composition. This study indicates that temporal changes in water conditions and eutrophication-induced hypoxia effectively shape the structure of the microbial community.


Data ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 44
Author(s):  
Jae-Hyun Lim ◽  
Il-Nam Kim

Marine bacteria are known to play significant roles in marine biogeochemical cycles regarding the decomposition of organic matter. Despite the increasing attention paid to the study of marine bacteria, research has been too limited to fully elucidate the complex interaction between marine bacterial communities and environmental variables. Jinhae Bay, the study area in this work, is the most anthropogenically eutrophied coastal bay in South Korea, and while its physical and biogeochemical characteristics are well described, less is known about the associated changes in microbial communities. In the present study, we reconstructed a metagenomics data based on the 16S rRNA gene to investigate temporal and vertical changes in microbial communities at three depths (surface, middle, and bottom) during a seven-month period from June to December 2016 at one sampling site (J1) in Jinhae Bay. Of all the bacterial data, Proteobacteria, Bacteroidetes, and Cyanobacteria were predominant from June to November, whereas Firmicutes were predominant in December, especially at the middle and bottom depths. These results show that the composition of the microbial community is strongly associated with temporal changes. Furthermore, the community compositions were markedly different between the surface, middle, and bottom depths in summer, when water column stratification and bottom water hypoxia (low dissolved oxygen level) were strongly developed. Metagenomics data contribute to improving our understanding of important relationships between environmental characteristics and microbial community change in eutrophication-induced and deoxygenated coastal areas.


Anaerobe ◽  
2010 ◽  
Vol 16 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Kimberly L. Cook ◽  
Michael J. Rothrock ◽  
Nanh Lovanh ◽  
John K. Sorrell ◽  
John H. Loughrin

2014 ◽  
Vol 86 (1-2) ◽  
pp. 547-554 ◽  
Author(s):  
Nam Sook Kim ◽  
Sang Hee Hong ◽  
Un Hyuk Yim ◽  
Kyung-Hoon Shin ◽  
Won Joon Shim

Author(s):  
Jun-Sik Lim ◽  
Eunbi Noh ◽  
Eunha Shim ◽  
Sukhyun Ryu

Abstract In order to identify the temporal change in the possible risk of superspreading events (SSE), we estimated the overdispersion parameter in two different periods of COVID-19 pandemic. We identified the possible risk of SSE was reduced 90% during the second epidemic period in South Korea.


2020 ◽  
Vol 96 (12) ◽  
Author(s):  
Lee J Pinnell ◽  
Jeffrey W Turner

ABSTRACT Plastic is a ubiquitous pollutant in the marine environment. Here, we investigated how temporal changes in environmental factors affect the microbial communities formed on plastic (polyethylene terephthalate; PET) versus a ceramic substrate. In situ mesocosms (N = 90 replicates) were deployed at the sediment–water interface of a coastal lagoon and sampled every 4 weeks for 424 days. Sequencing data (16S rRNA) was parsed based on variation in temperature with the exposure starting in fall 2016 and remaining in situ through the next four seasons (winter, spring, summer and fall 2017). PET biofilms were distinct during the summer when salinity and temperature were highest. In particular, a significant shift in the relative abundance of Ignavibacteriales and Cytophagales was observed during the summer, but PET and ceramic communities were again indistinguishable the following fall. Water temperature, salinity and pH were significant drivers of PET biofilm diversity as well as the relative abundance of plastic-discriminant taxa. This study illustrates the temporal and successional dynamics of PET biofilms and clearly demonstrates that increased water temperature, salinity, pH and exposure length play a role in the formation of a plastic-specific microbial community, but this specificity can be lost with a change in environmental conditions.


2015 ◽  
Vol 137 ◽  
pp. 66-76 ◽  
Author(s):  
Rita Susilawati ◽  
Paul N. Evans ◽  
Joan S. Esterle ◽  
Steven J. Robbins ◽  
Gene W. Tyson ◽  
...  

2021 ◽  
Vol 43 (1) ◽  
pp. 43-50
Author(s):  
Juhee Shin ◽  
Youngback Kim ◽  
Seung Gu Shin

Objectives:This study was performed to compare three commercial kits for the extraction of genomic DNA from anaerobic digestate for subsequent iSeq 100 sequencing and microbial community analysis.Methods:A full-scale mesophilic biogas plant was sampled, and made into aliquots of identical volumes to extract DNA using three commercial kits: FastDNA spin kit for soil (MP Biomedicals, USA), Exgene stool DNA mini (GeneAll, South Korea) and AccuPrep genomic DNA extraction kit (Bioneer, South Korea). To analyze the microbial communities in the purified DNA, 16S rDNA amplicon sequencing (V3-4 region for bacteria and V4-5 region for archaea) was performed on the Illumina iSeq 100 platform. Quality filtered sequence reads were OTU-clustered for taxonomic assignment conducted using the RDP classifier on-line.Results and Discussion:The microbial community structure visualized on the NMDS plot using the weighted UniFrac distance revealed that both bacteria and archaeal communities have phylogenetic differences depending on the DNA extraction kit used. In addition, the abundance of certain microbial populations was significantly different among the DNA extraction methods. For example, Proteobacteria was the least abundant using the soil kit, while this phylum was the most abundant when the stool kit was used. However, in the case of Thermotogae, this tendency was vice versa. The abundance of archaeal genera Methanomethylovorans and Methanosarcina was also affected by DNA extraction methods.Conclusions:The microbial populations analyzed by 16S based sequencing were affected by DNA extraction methods. To compare microbial community changes in the identical set of research, one DNA extraction method should be chosen and used consistently for the whole experiment.


Sign in / Sign up

Export Citation Format

Share Document