scholarly journals Successional patterns of (trace) metals and microorganisms in the Rainbow hydrothermal vent plume at the Mid-Atlantic Ridge

Author(s):  
Sabine Haalboom ◽  
David M. Price ◽  
Furu Mienis ◽  
Judith D. L. van Bleijswijk ◽  
Henko C. de Stigter ◽  
...  

Abstract. Hydrothermal vent fields found at mid-ocean ridges emit hydrothermal fluids which disperse as neutrally buoyant plumes. From these fluids seafloor massive sulfides (SMS) deposits are formed which are being explored as possible new mining sites for (trace) metals and rare earth elements (REE). It has been suggested that during mining activities large amounts of suspended matter will appear in the water column due to excavation processes, and due to discharge of mining waste from the surface vessel. Understanding how natural hydrothermal plumes evolve as they spread away from their source and how they affect their surrounding environment may provide some analogies for the behaviour of the dilute distal part of chemically enriched mining plumes. This study on the extensive Rainbow hydrothermal plume, observed up to 25 km downstream from the vent site, enabled us to investigate how microbial communities change in the presence of a natural plume. The (trace) metal and REE content of suspended particulate matter (SPM) was determined using HR-ICP mass spectrometry and the microbial communities of the neutrally buoyant plume, above plume-, below plume-, and near-bottom water and sediment were characterised by using 16S rRNA amplicon sequencing methods. Both vertically in the water column and horizontally along the neutrally buoyant plume, geochemical and biological changes were evident as the neutrally buoyant plume stood out by its enrichments in (trace) metals and REEs, of which the concentrations changed as the plume aged. This was also reflected in the background pelagic system as Epsilonproteobacteria started to dominate and the biodiversity appeared to reduce with distance away from the Rainbow hydrothermal vent field. The Rainbow hydrothermal plume provides a geochemically enriched natural environment, which is a heterogeneous, dynamic habitat that is conducive to ecological changes in a short time span.

2020 ◽  
Vol 17 (9) ◽  
pp. 2499-2519
Author(s):  
Sabine Haalboom ◽  
David M. Price ◽  
Furu Mienis ◽  
Judith D. L. van Bleijswijk ◽  
Henko C. de Stigter ◽  
...  

Abstract. Hydrothermal vent fields found at mid-ocean ridges emit hydrothermal fluids that disperse as neutrally buoyant plumes. From these fluids seafloor massive sulfides (SMS) deposits are formed, which are being explored as possible new mining sites for (trace) metals and rare earth elements (REEs). It has been suggested that during mining activities large amounts of suspended matter will appear in the water column due to excavation processes and discharge of mining waste from the surface vessel. Understanding how hydrothermal plumes can be characterised by means of geochemistry and microbiology as they spread away from their source and how they affect their surrounding environment may help in characterising the behaviour of the dilute distal part of chemically enriched mining plumes. This study on the extensive Rainbow hydrothermal plume, observed up to 25 km downstream from the vent site, enabled us to investigate how microbial communities and (trace) metal composition change in a natural plume with distance. The (trace) metal and REE content of suspended particulate matter (SPM) was determined using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) with high resolution (HR), and the microbial communities of the neutrally buoyant plume, above-plume, below-plume, and near-bottom water and sediment were characterised by using 16S rRNA amplicon sequencing methods. Both vertically in the water column and horizontally along the neutrally buoyant plume, geochemical and biological changes were evident, as the neutrally buoyant plume stood out by its enrichments in (trace) metals and REEs, as, for example, Fe, Cu, V, Mn and REEs were enriched by factors of up to ∼80, ∼90, ∼52, ∼2.5 and ∼40, respectively, compared to above-plume water samples taken at 1000 m water depth. The concentrations of these elements changed as the plume aged, shown by the decrease in element ∕ Fe molar ratios of chalcophile elements (Cu, Co, Zn), indicative of rapid removal from the hydrothermal plume or removal from the solid phase. Conversely, increasing REE ∕ Fe molar ratios imply uptake of REEs from the ambient seawater onto Fe-oxyhydroxides. This was also reflected in the background pelagic system, as Epsilonproteobacteria started to dominate and univariate microbial biodiversity declined with distance away from the Rainbow hydrothermal vent field. The Rainbow hydrothermal plume provides a geochemically enriched natural environment, which is a heterogeneous, dynamic habitat that is conducive to ecological changes in a short time span. This study of a hydrothermal plume provides a baseline study to characterise the natural plume before the interference of deep-sea mining.


2017 ◽  
Author(s):  
Eric R Hester ◽  
Sarah F. Harpenslager ◽  
Josepha MH van Diggelen ◽  
Leon L Lamers ◽  
Mike SM Jetten ◽  
...  

AbstractWetland ecosystems are important reservoirs of biodiversity and significantly contribute to emissions of the greenhouse gases CO2, N2O and CH4. High anthropogenic nitrogen (N) inputs from agriculture and fossil fuel combustion have been recognized as a severe threat to biodiversity and ecosystem functioning such as control of greenhouse gas emissions. Therefore it is important to understand how increased N input into pristine wetlands affects the composition and activity of micro-organisms, especially in interaction with dominant wetland plants. In a series of incubations analyzed over 90 days, we disentangle the effects of N fertilization on the microbial community in bulk soil and the rhizosphere ofJuncus acutiflorus, a common and abundant graminoid wetland plant. We observed an increase in greenhouse gas emissions when N is increased in incubations withJ. acutiflorus, changing the system from a greenhouse gas sink to a source. Using 16S rRNA amplicon sequencing and metagenomics, we determined that the bacterial orders Opitutales, Subgroup-6 Acidobacteria and Sphingobacteriales significantly responded to high N availability and we hypothesize that these groups are contributing to the increased greenhouse gas emissions. These results indicated that increased N input leads to shifts in microbial activity within the rhizosphere, severely altering N cycling dynamics. Our study provides a framework for connecting environmental conditions of wetland bulk and rhizosphere soil to the structure and metabolic output of microbial communities.


2021 ◽  
Author(s):  
Ying Zhang ◽  
Yang Huo ◽  
Zhiruo Zhang ◽  
Suiyi Zhu ◽  
Wei Fan ◽  
...  

Abstract We conducted physicochemical parameters analysis, 16S rRNA amplicon sequencing and real-time quantitative polymerase chain reaction to explore the impact of human inputs on the bacterioplankton communities within a tributary of the largest river flowing through a megacity in northeast China. Agriculture largely accounted for the alteration of diversity and functions of the microbial communities. Furthermore, nutrients were significantly declined at the reservoir outlet, and WWTP effluent discharge caused changes in the river microbial community. NH3-N and NO3--N were the main environmental factors that drive the shift of the bacteria community, and rare taxa played a more important role in the response to environmental changes compared with the abundant ones. The occurrence of the human-specific fecal indicator was mostly derived from agriculture, and its increase in relative abundance was observed in the effluent. Thus, our study provides guidance for ecological assessment and management of rivers by revealing the response pattern of river bacterioplankton to multiple types of anthropogenic stressors.


2020 ◽  
Author(s):  
Kasun H Bodawatta ◽  
Katerina Puzejova ◽  
Katerina Sam ◽  
Michael Poulsen ◽  
Knud A. Jønsson

Abstract Background Comprehensive studies of wild bird microbiomes are often limited by difficulties of sample acquisition. However, widely used non-invasive cloacal swab methods and under-explored museum specimens preserved in alcohol provide promising avenues to increase our understanding of wild bird microbiomes, provided that they accurately portray natural microbial community compositions. To investigate this assertion, we used 16S rRNA amplicon sequencing of Great tit (Parus major) gut microbiomes to compare 1) microbial communities obtained from dissected digestive tract regions and cloacal swabs, and 2) microbial communities obtained from freshly dissected gut regions and from samples preserved in alcohol for two weeks or two months, respectively. Results We found no significant differences in alpha diversities in communities of different gut regions and cloacal swabs (except in OTU richness between the dissected cloacal region and the cloacal swabs), or between fresh and alcohol preserved samples. However, we did find significant differences in beta diversity and community composition of cloacal swab samples compared to different gut regions. Despite these community-level differences, swab samples qualitatively captured the majority of the bacterial diversity throughout the gut better than any single compartment. Bacterial community compositions of alcohol-preserved specimens did not differ significantly from freshly dissected samples, although some low-abundant taxa were lost in the alcohol preserved specimens. Conclusions Our findings suggest that cloacal swabs, similar to non-invasive fecal sampling, qualitatively depict the gut microbiota composition without having to collect birds to extract the full digestive tract. Secondly, the satisfactory depiction of gut microbial communities in alcohol preserved samples opens up for the possibility of using an enormous resource readily available through museum collections to characterize bird gut microbiomes. The use of extensive museum specimen collections of birds for microbial gut analyses would allow for investigations of temporal patterns of wild bird gut microbiomes, including the potential effects of climate change and anthropogenic impacts. Overall, the utilization of cloacal swabs and museum alcohol specimens can positively impact bird gut microbiome research to help increase our understanding of the role and evolution of wild bird hosts and gut microbial communities.


Author(s):  
Peter J. Flynn ◽  
Catherine L. D’Amelio ◽  
Jon G. Sanders ◽  
Jacob A. Russell ◽  
Corrie S. Moreau

Microbial communities within the animal digestive tract often provide important functions for their hosts. The composition of eukaryotes' gut bacteria can be shaped by host diet, vertical bacterial transmission, and physiological variation within the digestive tract. In several ant taxa, recent findings have demonstrated that nitrogen provisioning by symbiotic bacteria makes up for deficiencies in herbivorous diets. Using 16S rRNA amplicon sequencing and qPCR, this study examined bacterial communities at a fine scale across one such animal group, the turtle ant genus Cephalotes. We analyzed the composition and colonization density across four portions of the digestive tract to understand how bacterial diversity is structured across gut compartments, potentially allowing for specific metabolic functions of benefit to the host. In addition, we aimed to understand if caste differentiation or host relatedness influences the gut bacterial communities of Cephalotes ants. Microbial communities were found to vary strongly across Cephalotes gut compartments in ways that transcend both caste and host phylogeny. Despite this, caste and host phylogeny still have detectable effects. We demonstrated microbial community divergence across gut compartments, possibly due to the varying function of each gut compartment for digestion. IMPORTANCE Gut compartments play an important role in structuring the microbial community within individual ants. The gut chambers of the turtle ant digestive tract differ remarkably in symbiont abundance and diversity. Furthermore, caste type explains some variation in the microbiome composition. Finally, the evolutionary history of the Cephalotes species structures the microbiome in our study, which elucidates a trend in which related ants maintain related microbiomes, conceivably owing to co-speciation. Amazingly, gut compartment-specific signatures of microbial diversity, relative abundance, composition, and abundance have been conserved over Cephalotes evolutionary history, signifying that this symbiosis has been largely stable for over 50 million years.


2021 ◽  
Vol 10 (5) ◽  
Author(s):  
Sania Arif ◽  
Elias Schliekmann ◽  
Michael Hoppert

ABSTRACT The 16S rRNA amplicons from biofilms inhabiting rocks near various water bodies of Marsberg Copper Mine (Rhenish Massif, Germany) reveal the diversity of their microbial communities. The abundance of Chloroflexi and Cyanobacteria taxa in the biofilms near leachate streams indicated the selective enrichment of Ktedonobacteria and Oxyphotobacteria members.


2021 ◽  
Author(s):  
Raymond B. Banister ◽  
Melbert T. Schwarz ◽  
Maoz Fine ◽  
Kim B. Ritchie ◽  
Erinn M. Muller

AbstractSeagrass meadows are hotspots of biodiversity with considerable economic and ecological value. The health of seagrass ecosystems is influenced in part by the makeup and stability of their microbiome, but microbiome composition can be sensitive to environmental change such as nutrient availability, elevated temperatures, and reduced pH. The objective of the present study was to characterize the bacterial community of the leaves, bulk samples of roots and rhizomes, and proximal sediment of the seagrass species Cymodocea nodosa along the natural pH gradient of Levante Bay, Vulcano Island, Italy. The bacterial community was determined by characterizing the 16S rRNA amplicon sequencing and analyzing the operational taxonomic unit classification of bacterial DNA within samples. Statistical analyses were used to explore how life-long exposure to different pH/pCO2 conditions may be associated with significant differences in microbial communities, dominant bacterial classes, and microbial diversity within each plant section and sediment. The microbiome of C. nodosa significantly differed among all sample types and site-specific differences were detected within sediment and root/rhizome microbial communities, but not the leaves. These results show that C. nodosa leaves have a consistent microbial community even across a pH range of 8.15 to 6.05. The ability for C. nodosa to regulate and maintain microbial structure may indicate a semblance of resilience within these vital ecosystems under projected changes in environmental conditions such as ocean acidification.


Author(s):  
Flávio C. F. Baleeiro ◽  
Sabine Kleinsteuber ◽  
Heike Sträuber

Electron donor scarcity is seen as one of the major issues limiting economic production of medium-chain carboxylates from waste streams. Previous studies suggest that co-fermentation of hydrogen in microbial communities that realize chain elongation relieves this limitation. To better understand how hydrogen co-feeding can support chain elongation, we enriched three different microbial communities from anaerobic reactors (A, B, and C with ascending levels of diversity) for their ability to produce medium-chain carboxylates from conventional electron donors (lactate or ethanol) or from hydrogen. In the presence of abundant acetate and CO2, the effects of different abiotic parameters (pH values in acidic to neutral range, initial acetate concentration, and presence of chemical methanogenesis inhibitors) were tested along with the enrichment. The presence of hydrogen facilitated production of butyrate by all communities and improved production of i-butyrate and caproate by the two most diverse communities (B and C), accompanied by consumption of acetate, hydrogen, and lactate/ethanol (when available). Under optimal conditions, hydrogen increased the selectivity of conventional electron donors to caproate from 0.23 ± 0.01 mol e–/mol e– to 0.67 ± 0.15 mol e–/mol e– with a peak caproate concentration of 4.0 g L–1. As a trade-off, the best-performing communities also showed hydrogenotrophic methanogenesis activity by Methanobacterium even at high concentrations of undissociated acetic acid of 2.9 g L–1 and at low pH of 4.8. According to 16S rRNA amplicon sequencing, the suspected caproate producers were assigned to the family Anaerovoracaceae (Peptostreptococcales) and the genera Megasphaera (99.8% similarity to M. elsdenii), Caproiciproducens, and Clostridium sensu stricto 12 (97–100% similarity to C. luticellarii). Non-methanogenic hydrogen consumption correlated to the abundance of Clostridium sensu stricto 12 taxa (p < 0.01). If a robust methanogenesis inhibition strategy can be found, hydrogen co-feeding along with conventional electron donors can greatly improve selectivity to caproate in complex communities. The lessons learned can help design continuous hydrogen-aided chain elongation bioprocesses.


2022 ◽  
Author(s):  
Muhammed Fatih Sert ◽  
Helge Niemann ◽  
Eoghan P. Reeves ◽  
Mats A. Granskog ◽  
Kevin P. Hand ◽  
...  

Abstract. Hydrothermal vents modify and displace subsurface dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM is transported together with elements, particles, dissolved gases, and biomass along with the neutrally buoyant plume layer. Considering the number and extent of actively venting hydrothermal sites in the oceans, their contribution to the oceanic DOM pool may be substantial. Here, we investigate the dynamics of DOM in relation to hydrothermal venting and related processes at the as-yet unexplored Aurora hydrothermal vent field within the ultraslow spreading Gakkel Ridge in the Arctic Ocean at 82.9° N. We examined the vertical distribution of DOM composition from sea ice to deep waters at six hydrocast stations distal to the active vent and its neutrally buoyant plume layer. In comparison to background seawater, we found that the DOM in waters directly affected by the hydrothermal plume was composed of lower numbers of molecular formulas and 5–10 % less abundant compositions associated with the molecular categories related to lipid and protein-like compounds. Samples that were not directly affected by the plume, on the other hand, were chemically more diverse and had a higher percentage of chemical formulas associated with the carbohydrate-like category. We suggest, therefore, that hydrothermal processes at Aurora may influence the DOM distribution in the bathypelagic ocean by spreading more thermally and/or chemically induced compositions, while DOM compositions in epipelagic and mesopelagic layers are mainly governed by the microbial carbon pump dynamics, and sea ice surface water interactions.


Sign in / Sign up

Export Citation Format

Share Document