scholarly journals Diversity and Abundance of Aerobic and Anaerobic Methane Oxidizers at the Haakon Mosby Mud Volcano, Barents Sea

2007 ◽  
Vol 73 (10) ◽  
pp. 3348-3362 ◽  
Author(s):  
Tina Lösekann ◽  
Katrin Knittel ◽  
Thierry Nadalig ◽  
Bernhard Fuchs ◽  
Helge Niemann ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Barents Sea ◽  
Aerobic Oxidation ◽  
Active Volcano ◽  
Comparative Sequence Analysis ◽  
16S Rrna Genes ◽  
Mud Volcano ◽  
Rrna Genes ◽  
Methane Seepage ◽  
Aerobic And Anaerobic

ABSTRACT Submarine mud volcanoes are formed by expulsions of mud, fluids, and gases from deeply buried subsurface sources. They are highly reduced benthic habitats and often associated with intensive methane seepage. In this study, the microbial diversity and community structure in methane-rich sediments of the Haakon Mosby Mud Volcano (HMMV) were investigated by comparative sequence analysis of 16S rRNA genes and fluorescence in situ hybridization. In the active volcano center, which has a diameter of about 500 m, the main methane-consuming process was bacterial aerobic oxidation. In this zone, aerobic methanotrophs belonging to three bacterial clades closely affiliated with Methylobacter and Methylophaga species accounted for 56% ± 8% of total cells. In sediments below Beggiatoa mats encircling the center of the HMMV, methanotrophic archaea of the ANME-3 clade dominated the zone of anaerobic methane oxidation. ANME-3 archaea form cell aggregates mostly associated with sulfate-reducing bacteria of the Desulfobulbus (DBB) branch. These ANME-3/DBB aggregates were highly abundant and accounted for up to 94% ± 2% of total microbial biomass at 2 to 3 cm below the surface. ANME-3/DBB aggregates could be further enriched by flow cytometry to identify their phylogenetic relationships. At the outer rim of the mud volcano, the seafloor was colonized by tubeworms (Siboglinidae, formerly known as Pogonophora). Here, both aerobic and anaerobic methane oxidizers were found, however, in lower abundances. The level of microbial diversity at this site was higher than that at the central and Beggiatoa species-covered part of the HMMV. Analysis of methyl-coenzyme M-reductase alpha subunit (mcrA) genes showed a strong dominance of a novel lineage, mcrA group f, which could be assigned to ANME-3 archaea. Our results further support the hypothesis of Niemann et al. (54), that high methane availability and different fluid flow regimens at the HMMV provide distinct niches for aerobic and anaerobic methanotrophs.

scholarly journals Abundance and Microbial Diversity from Surface to Deep Water Layers Over the Rio Grande Rise, South Atlantic

2021 ◽  
Author(s):  
Juliana Correa Neiva Ferreira ◽  
Natascha M. Bergo ◽  
Pedro M. Tura ◽  
Mateus Gustavo Chuqui ◽  
Frederico P. Brandini ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Diversity ◽  
Rio Grande ◽  
South Atlantic ◽  
Water Masses ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
List Type ◽  
Tropical Water ◽  
Southwestern Atlantic Ocean

AbstractMarine microbes control the flux of matter and energy essential for life in the oceans. Until now, the distribution and diversity of planktonic microorganisms above Fe-Mn crusts has received relatively little attention. Future mining\dredging of these minerals is predicted to affect microbial diversity and functioning in the deep sea. Here, we studied the ecology of planktonic microbes among pelagic environments of an Fe-Mn deposit region, at Rio Grande Rise, Southwestern Atlantic Ocean. We investigated microbial community composition using high-throughput sequencing of 16S rRNA genes and their abundance estimated by flow cytometry. Our results showed that the majority of picoplanktonic was found in epi- and mesopelagic waters, corresponding to the Tropical Water and South Atlantic Central Water. Bacterial and archaeal groups related to phototrophy, heterotrophy and chemosynthesis, such as Synechococcales, Sar11 (Proteobacteria) and Nitrosopumilales (Thaumarchaeota) were the main representatives of the pelagic microbial community. Additionally, we detected abundant assemblages involved in biodegradation of marine organic matter and iron oxidation at deep waters, i.e., Pseudoalteromonas and Alteromonas. No differences were observed in microbial community alpha diversity. However, we detected differences in community structure between water masses, suggesting that changes in an environmental setting (i.e. nutrient availability or circulation) play a significant role in structuring the pelagic zones, also affecting the meso- and bathypelagic microbiome.HighlightsRio Grande Rise pelagic microbiomePicoplankton carbon biomass partitioning through pelagic zonesUnique SAR11 Clade I oligotype in the shallowest Tropical WaterHigher number of shared oligotypes between deepest water massesNitrogen, carbon and sulfur may be important contributors for the pelagic microbiome

Abundance, diversity and mobility potential of antibiotic resistance genes in pristine Tibetan Plateau soil as revealed by soil metagenomics

2020 ◽  
Vol 96 (10) ◽  
Author(s):  
Bo Li ◽  
Zeng Chen ◽  
Fan Zhang ◽  
Yongqin Liu ◽  
Tao Yan
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Diversity ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Soil Samples ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Metagenomic Sequencing ◽  
Clinical Issue ◽  
Abundance And Diversity

ABSTRACT Widespread occurrence of antibiotic resistance genes (ARGs) has become an important clinical issue. Studying ARGs in pristine soil environments can help to better understand the intrinsic soil resistome. In this study, 10 soil samples were collected from a high elevation and relatively pristine Tibetan area, and metagenomic sequencing and bioinformatic analyses were conducted to investigate the microbial diversity, the abundance and diversity of ARGs and the mobility potential of ARGs as indicated by different mobile genetic elements (MGEs). A total of 48 ARG types with a relative abundance of 0.05–0.28 copies of ARG/copy of 16S rRNA genes were detected in Tibetan soil samples. The observed ARGs were mainly associated with antibiotics that included glycopeptide and rifamycin; the most abundant ARGs were vanRO and vanSO. Low abundance of MGEs and potentially plasmid-related ARGs indicated a low horizontal gene transfer risk of ARGs in the pristine soil. Pearson correlation and redundancy analyses showed that temperature and total organic carbon were the major environmental factors controlling both microbial diversity and ARG abundance and diversity.

scholarly journals Depth Distribution of Microbial Diversity in Mono Lake, a Meromictic Soda Lake in California

2003 ◽  
Vol 69 (2) ◽  
pp. 1030-1042 ◽  
Author(s):  
Shaheen B. Humayoun ◽  
Nasreen Bano ◽  
James T. Hollibaugh
Keyword(s):  
Microbial Diversity ◽  
Water Samples ◽  
Soda Lake ◽  
Niche Differentiation ◽  
Mono Lake ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Surface Water Samples

ABSTRACT We analyzed the variation with depth in the composition of members of the domain Bacteria in samples from alkaline, hypersaline, and currently meromictic Mono Lake in California. DNA samples were collected from the mixolimnion (2 m), the base of the oxycline (17.5 m), the upper chemocline (23 m), and the monimolimnion (35 m). Composition was assessed by sequencing randomly selected cloned fragments of 16S rRNA genes retrieved from the DNA samples. Most of the 212 sequences retrieved from the samples fell into five major lineages of the domain Bacteria: α- and γ-Proteobacteria (6 and 10%, respectively), Cytophaga-Flexibacter-Bacteroides (19%), high-G+C-content gram-positive organisms (Actinobacteria; 25%), and low-G+C-content gram-positive organisms (Bacillus and Clostridium; 19%). Twelve percent were identified as chloroplasts. The remaining 9% represented β- and δ-Proteobacteria, Verrucomicrobiales, and candidate divisions. Mixolimnion and oxycline samples had low microbial diversity, with only 9 and 12 distinct phylotypes, respectively, whereas chemocline and monimolimnion samples were more diverse, containing 27 and 25 phylotypes, respectively. The compositions of microbial assemblages from the mixolimnion and oxycline were not significantly different from each other (P = 0.314 and 0.877), but they were significantly different from those of chemocline and monimolimnion assemblages (P < 0.001), and the compositions of chemocline and monimolimnion assemblages were not significantly different from each other (P = 0.006 and 0.124). The populations of sequences retrieved from the mixolimnion and oxycline samples were dominated by sequences related to high-G+C-content gram-positive bacteria (49 and 63%, respectively) distributed in only three distinct phylotypes, while the population of sequences retrieved from the monimolimnion sample was dominated (52%) by sequences related to low-G+C-content gram-positive bacteria distributed in 12 distinct phylotypes. Twelve and 28% of the sequences retrieved from the chemocline sample were also found in the mixolimnion and monimolimnion samples, respectively. None of the sequences retrieved from the monimolimnion sample were found in the mixolimnion or oxycline samples. Elevated diversity in anoxic bottom water samples relative to oxic surface water samples suggests a greater opportunity for niche differentiation in bottom versus surface waters of this lake.

scholarly journals High Diversity in Iron Cycling Microbial Communities in Acidic, Iron-Rich Water of the Pyhäsalmi Mine, Finland

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Malin Bomberg ◽  
Jarno Mäkinen ◽  
Marja Salo ◽  
Päivi Kinnunen
Keyword(s):  
16S Rrna ◽  
Microbial Diversity ◽  
Microbial Communities ◽  
Mine Water ◽  
Ferrous Iron ◽  
Great Part ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Iron Oxidizers

Microbial communities of iron-rich water in the Pyhäsalmi mine, Finland, were investigated with high-throughput amplicon sequencing and qPCR targeting bacteria, archaea, and fungi. In addition, the abundance ofLeptospirillumandAcidithiobacilluswas assessed with genus-specific qPCR assays, and enrichment cultures targeting aerobic ferrous iron oxidizers and ferric iron reducers were established. The acidic (pH 1.4–2.3) mine water collected from 240 m, 500 m, and 600 m depth from within the mine had a high microbial diversity consisting of 63-114 bacterial, 10-13 archaeal, and 104-117 fungal genera. The most abundant microorganisms in the mine water were typical acid mine drainage (AMD) taxa, such as acidophilic, iron-oxidizingLeptospirillum,Acidiphilum,Acidithiobacillus,Ferrovum, andThermoplasma. The fungi belonged mostly to the phylum Ascomycetes, although a great part of the fungal sequences remained unclassified. The number of archaeal 16S rRNA genes in the mine water was between 0.3 and 1.2 × 107copies mL−1in the samples from 500 m and 600 m, but only 3.9 × 103at 240 m and archaea were in general not enriched in cultures. The number of fungal 5.8S rRNA genes was high only in the mine water from 500 m and 600 m, where 0.2–3.4 × 104spore equivalents mL−1were detected. A high number ofLeptospirillum16S rRNA genes, 0.6–1.6 × 1010copies mL−1, were detected at 500 m and 600 m depth and in cultures containing ferrous iron, showing the importance of iron oxidizers in this environment. The abundance of bacteria in general was between 103and 10616S rRNA gene copies mL−1. Our results showed a high microbial diversity in the acid- and iron-impacted waters of the Pyhäsalmi mine, whereLeptospirillumbacteria were especially prominent. These iron oxidizers are also the main nitrogen-fixing microorganisms in this ecosystem.

scholarly journals Diversity and composition of the Panax ginseng rhizosphere microbiome in various cultivation modesand ages

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ai-Zi Tong ◽  
Wei Liu ◽  
Qiang Liu ◽  
Guang-Qing Xia ◽  
Jun-Yi Zhu
Keyword(s):  
Microbial Community ◽  
Microbial Diversity ◽  
Panax Ginseng ◽  
Soil Microbial Communities ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Continuous Cropping ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Soil Borne Pathogens

Abstract Background Continuous cropping of ginseng (Panax ginseng Meyer) cultivated in farmland for an extended period gives rise to soil-borne disease. The change in soil microbial composition is a major cause of soil-borne diseases and an obstacle to continuous cropping. The impact of cultivation modes and ages on the diversity and composition of the P. ginseng rhizosphere microbial community and technology suitable for cropping P. ginseng in farmland are still being explored. Methods Amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions were analyzed for microbial community composition and diversity. Results The obtained sequencing data were reasonable for estimating soil microbial diversity. We observed significant variations in richness, diversity, and relative abundances of microbial taxa between farmland, deforestation field, and different cultivation years. The bacterial communities of LCK (forest soil where P. ginseng was not grown) had a much higher richness and diversity than those in NCK (farmland soil where P. ginseng was not grown). The increase in cultivation years of P. ginseng in farmland and deforestation field significantly changed the diversity of soil microbial communities. In addition, the accumulation of P. ginseng soil-borne pathogens (Monographella cucumerina, Ilyonectria mors-panacis, I. robusta, Fusarium solani, and Nectria ramulariae) varied with the cropping age of P. ginseng. Conclusion Soil microbial diversity and function were significantly poorer in farmland than in the deforestation field and were affected by P. ginseng planting years. The abundance of common soil-borne pathogens of P. ginseng increased with the cultivation age and led to an imbalance in the microbial community.

scholarly journals Growing the recalcitrant

2007 ◽  
Vol 28 (3) ◽  
pp. 127
Author(s):  
Peter H Janssen
Keyword(s):  
16S Rrna ◽  
Microbial Diversity ◽  
16S Rrna Genes ◽  
Rrna Genes

Unculturable microorganisms are those that have been identifiedby microscopy, by their activity or by detection of phylogenetic markers such as their 16S rRNA genes, and have not been able to be cultured, despite reasonable efforts having been made. Recent successes in the cultivation of so-called unculturable microorganisms have revealed that the key ingredient in therecipe for growing them in the laboratory is patience. Beyond that, there is probably no single secret to success and microbial diversity must be matched by experimental ingenuity.

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