scholarly journals Sargassum Differentially Shapes the Microbiota Composition and Diversity at Coastal Tide Sites and Inland Storage Sites on Caribbean Islands

2021 ◽  
Vol 12 ◽  
Author(s):  
Vincent Hervé ◽  
Josie Lambourdière ◽  
Malika René-Trouillefou ◽  
Damien Alain Devault ◽  
Pascal Jean Lopez

Rafts of drifting pelagic Sargassum that are circulating across the Atlantic Ocean are complex ecosystems composed of a large number of associated species. Upon massive stranding, they lead to various socio-environmental issues including the inflow of contaminants and human health concerns. In this study, we used metabarcoding approaches to examine the differences in both the eukaryotic- and prokaryotic-associated communities from Sargassum present in two islands of the Lesser Antilles, namely Guadeloupe and Martinique. We detected significant differences in microbial community structure and composition between landing Sargassum, the surrounding seawater, and Sargassum from inland storage sites. In total we identified 22,214 prokaryotic and 17,679 eukaryotic OTUs. Among them, functional prediction analyses revealed a number of prokaryotes that might contribute to organic matter decomposition, nitrogen cycling and gas production, including sulfate-reducing bacteria at coastal landing sites, and methanogenic archaea at inland storage sites. We also found that Metazoan was the most abundant group in Sargassum samples, with nematode clades that presented exclusive or specific richness and abundance patterns depending on their Sargassum substrate. Together, these molecular inventories of the micro- and meiofauna communities provide baseline information for further characterization of trophic interactions, algal organic matter decomposition and nutrient transfers at coastal and inland storage sites.

2005 ◽  
Vol 52 (1-2) ◽  
pp. 13-20 ◽  
Author(s):  
A.J.M. Stams ◽  
C.M. Plugge ◽  
F.A.M. de Bok ◽  
B.H.G.W. van Houten ◽  
P. Lens ◽  
...  

In environments where the amount of electron acceptors is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic consortia of acetogenic bacteria and methanogenic archaea. Hydrogen consumption by methanogens is essential for acetogenic bacteria to convert organic acids to acetate and hydrogen. Several syntrophic cocultures growing on propionate and butyrate have been described. These syntrophic fatty acid-degrading consortia are affected by the presence of sulfate. When sulfate is present sulfate-reducing bacteria compete with methanogenic archaea for hydrogen and acetate, and with acetogenic bacteria for propionate and butyrate. Sulfate-reducing bacteria easily outcompete methanogens for hydrogen, but the presence of acetate as carbon source may influence the outcome of the competition. By contrast, acetoclastic methanogens can compete reasonably well with acetate-degrading sulfate reducers. Sulfate-reducing bacteria grow much faster on propionate and butyrate than syntrophic consortia.


Author(s):  
Aung Kyaw Phyo ◽  
Yan Jia ◽  
Qiaoyi Tan ◽  
Heyun Sun ◽  
Yunfeng Liu ◽  
...  

Mining waste rocks containing sulfide minerals naturally provide the habitat for iron- and sulfur-oxidizing microbes, and they accelerate the generation of acid mine drainage (AMD) by promoting the oxidation of sulfide minerals. Sulfate-reducing bacteria (SRB) are sometimes employed to treat the AMD solution by microbial-induced metal sulfide precipitation. It was attempted for the first time to grow SRB directly in the pyritic heap bioleaching residue to compete with the local iron- and sulfur-oxidizing microbes. The acidic SRB and iron-reducing microbes were cultured at pH 2.0 and 3.0. After it was applied to the acidic heap bioleaching residue, it showed that the elevated pH and the organic matter was important for them to compete with the local bioleaching acidophiles. The incubation with the addition of organic matter promoted the growth of SRB and iron-reducing microbes to inhibit the iron- and sulfur-oxidizing microbes, especially organic matter together with some lime. Under the growth of the SRB and iron-reducing microbes, pH increased from acidic to nearly neutral, the Eh also decreased, and the metal, precipitated together with the microbial-generated sulfide, resulted in very low Cu in the residue pore solution. These results prove the inhibition of acid mine drainage directly in situ of the pyritic waste rocks by the promotion of the growth of SRB and iron-reducing microbes to compete with local iron and sulfur-oxidizing microbes, which can be used for the source control of AMD from the sulfidic waste rocks and the final remediation.


2017 ◽  
Vol 35 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Jennifer B. Glass ◽  
Si Chen ◽  
Katherine S. Dawson ◽  
Damian R. Horton ◽  
Stefan Vogt ◽  
...  

2021 ◽  
Author(s):  
Grayson L Chadwick ◽  
Connor T Skennerton ◽  
Rafael Laso-Perez ◽  
Andy O Leu ◽  
Daan R Speth ◽  
...  

The anaerobic oxidation of methane coupled to sulfate reduction is a microbially mediated process requiring a syntrophic partnership between anaerobic methanotrophic (ANME) archaea and sulfate reducing bacteria (SRB). Based on genome taxonomy, ANME lineages are polyphyletic within the phylum Halobacterota, none of which have been isolated in pure culture. Here we reconstruct 28 ANME genomes from environmental metagenomes and flow sorted syntrophic consortia. Together with a reanalysis of previously published datasets, these genomes enable a comparative analysis of all marine ANME clades. We review the genomic features which separate ANME from their methanogenic relatives and identify what differentiates ANME clades. Large multiheme cytochromes and bioenergetic complexes predicted to be involved in novel electron bifurcation reactions are well-distributed and conserved in the ANME archaea, while significant variations in the anabolic C1 pathways exists between clades. Our analysis raises the possibility that methylotrophic methanogenesis may have evolved from a methanotrophic ancestor.


2020 ◽  
Author(s):  
Valerie De Anda ◽  
Lin-Xing Chen ◽  
Nina Dombrowski ◽  
Zhengshuang Hua ◽  
Hong-Chen Jiang ◽  
...  

Abstract Single carbon (C1) compounds such as methanol, methylamines and formaldehyde are ubiquitous in nature and they are large components of the carbon cycle. In anoxic environments C1-utilizing microbes (methylotrophs) play an important role in controlling global carbon degradation. Currently described anaerobic methylotrophs are limited to methanogenic archaea, acetogenic bacteria, and sulfate-reducing bacteria. Here, we report the first archaeal lineage outside of methanogenic taxa that are capable of anaerobic methylotrophy. Phylogenetic analyses suggest these archaea form a new phylum within the TACK superphylum, which we propose be named Brockarchaeota. A survey revealed Brockarchaeota are globally distributed in geothermal springs. Metabolic inference from 15 metagenome-assembled genomes from hot springs and deep-sea sediments indicates that Brockarchaeota are strict anaerobes. They contain a variety C1 metabolisms including the methanol and trimethylamine methyltransferases system, the ribulose bisphosphate pathway coupled with the non-oxidative pentoses phosphate pathway, and reductive glycine pathway. Brockarchaeota have an incomplete methyl-branch of the Wood-Ljungdahl pathway probably used for formaldehyde oxidation, since they lack several core genes involved in methanogenesis including methyl-CoM reductases. Brockarchaeota also appear to play an important role in the breakdown of plant-derived polysaccharides, especially cellulose, starch and xylan. Their broad distribution and their capacity to use both C1 compounds and complex polysaccharides via anaerobic metabolism suggest that the Brockarchaeota occupy previously overlooked roles in carbon cycling.


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