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Chunleuchanon, Somporn; Sooksawang, Apichat; Teaumroong, Neung; Boonkerd, Nantakorn

doi:10.1023/a:1023286823958

Cited by 16 publications

(1 citation statement)

References 17 publications

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“…Therefore, it is essential to study further the relationship between microbial communities and physicochemical parameters of the sediment. Many factors, including temperature, organic matter (OM), dissolved oxygen (DO), redox potential, and concentration gradient of the nutrient substances in the sediment, can significantly affect the structure, diversity, and metabolism of multiple microbial species in the medium (Chunleuchanon et al 2003). Among these factors, OM content is a key factor driving changes in bacterial activities.…”

Section: Introductionmentioning

confidence: 99%

Characterization of depth-related bacterial communities and their relationships with the environmental factors in the river sediments

Huang

Chen

et al. 2011

World J Microbiol Biotechnol

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To better understand the bacterial processes in river sediments, it is necessary to investigate the depthrelated bacterial communities in the whole sediment profile. Sediment samples were collected to a depth of 25 cm from the Pearl River. Bacterial abundance, activity, cellspecific respiration rate, and diversity were measured, respectively, by 4 0 , 6-diamidino-2-phenylindole direct count, 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) staining, electron transport system by CTC reduction, and denaturing gradient gel electrophoresis analysis of 16S rRNA amplification fragments. Results showed that the bacterial metabolism activities decreased with the sediment depth. The total bacterial abundance was highest in the surface sediment with 65.1 9 10 7 cells g -1 , and decreased to 11.1 9 10 7 cells g -1 below 20 cm in the sample location that suffered from heavy sewage inputs. The active bacteria accounted for 7.50-46.7% of the total bacterial number and decreased with the sediment depth. Electron transport system by the CTC reduction showed that bacterial respiration rate declined from 1.093 lmol CTC-formazan h -1 g -1 in the surface sediment to a half in the bottom sediment, while the cell-specific respiration increased significantly with the depth from 3.56 to 93.75 fmol CTCformazan cell -1 . The bacterial diversity also changed with the depth. Beta-Proteobacteria were the dominant species in the surface sediment, whereas Delta-Proteobacteria were the main species below 10 cm. Results of canonical correspondence analysis (CCA) indicated that the distribution of bacteria was affected by the combined effect of various dissolved inorganic matter, while the respiration rate was independent of the nutrient conditions. The specific bacterial distribution contributed to not only the nutrient cycle but also enhanced pollutant decomposition in sediment of the Pearl River. The results showed that some specific bacterial species had a strong activity in the deeper layers. Therefore, the metabolic functions of the deeper bacterial species should not be neglected.

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Section: Introductionmentioning

confidence: 99%

Characterization of depth-related bacterial communities and their relationships with the environmental factors in the river sediments

Huang

Chen

et al. 2011

World J Microbiol Biotechnol

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Is the methanogenic community reflecting the methane emissions of river sediments?—comparison of two study sites

2017

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Studies on methanogenesis from freshwater sediments have so far primarily focused on lake sediments. To expand our knowledge on the community composition of methanogenic archaea in river sediments, we studied the abundance and diversity of methanogenic archaea at two localities along a vertical profile (top 50 cm) obtained from sediment samples from Sitka stream (the Czech Republic). In this study, we compare two sites which previously have been shown to have a 10‐fold different methane emission. Archaeal and methanogen abundance were analyzed by real‐time PCR and T‐RFLP. Our results show that the absolute numbers for the methanogenic community (qPCR) are relatively stable along a vertical profile as well as for both study sites. This was also true for the archaeal community and for the three major methanogenic orders in our samples (Methanosarcinales, Methanomicrobiales, and Methanobacteriales). However, the underlying community structure (T‐RFLP) reveals different community compositions of the methanogens for both locations as well as for different depth layers and over different sampling times. In general, our data confirm that Methanosarcinales together with Methanomicrobiales are the two dominant methanogenic orders in river sediments, while members of Methanobacteriales contribute a smaller community and Methanocellales are only rarely present in this sediment. Our results show that the previously observed 10‐fold difference in methane emission of the two sites could not be explained by molecular methods alone.

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Dominance of Methanosarcinales Phylotypes and Depth-Wise Distribution of Methanogenic Community in Fresh Water Sediments of Sitka Stream from Czech Republic

et al. 2014

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The variation in the diversity of methanogens in sediment depths from Sitka stream was studied by constructing a 16S rRNA gene library using methanogen-specific primers and a denaturing gradient gel electrophoresis (DGGE)-based approach. A total of nine different phylotypes from the 16S rRNA library were obtained, and all of them were clustered within the order Methanosarcinales. These nine phylotypes likely represent nine new species and at least 5-6 new genera. Similarly, DGGE analysis revealed an increase in the diversity of methanogens with an increase in sediment depth. These results suggest that Methanosarcinales phylotypes might be the dominant methanogens in the sediment from Sitka stream, and the diversity of methanogens increases as the depth increases. Results of the present study will help in making effective strategies to monitor the dominant methanogen phylotypes and methane emissions in the environment.

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Cited by 16 publications

References 17 publications

Characterization of depth-related bacterial communities and their relationships with the environmental factors in the river sediments

Characterization of depth-related bacterial communities and their relationships with the environmental factors in the river sediments

Is the methanogenic community reflecting the methane emissions of river sediments?—comparison of two study sites

Dominance of Methanosarcinales Phylotypes and Depth-Wise Distribution of Methanogenic Community in Fresh Water Sediments of Sitka Stream from Czech Republic

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