scholarly journals Dramatic expansion of microbial groups that shape the global sulfur cycle

2017 ◽  
Author(s):  
Karthik Anantharaman ◽  
Sean P. Jungbluth ◽  
Rose S. Kantor ◽  
Adi Lavy ◽  
Lesley A. Warren ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Microbial Community Composition ◽  
Sulfur Oxidation ◽  
Sulfur Cycle ◽  
Process Models ◽  
Marker Genes ◽  
Biogeochemical Process ◽  
Sulfate Reducing ◽  
Microbial Sulfate Reduction ◽  
Microbial Groups

AbstractThe biogeochemical cycle of sulfur on Earth is driven by microbial sulfate reduction, yet organisms from relatively few lineages have been implicated in this process. Recent studies using functional marker genes have detected abundant, novel dissimilatory sulfite reductases that confer the capacity for microbial sulfate reduction and could do not be affiliated with known organisms. Thus, the identity of a significant fraction of sulfate reducing microbes has remained elusive. Here we report the discovery of the capacity for sulfate reduction in the genomes of organisms from twelve bacterial and archaeal phyla, thereby doubling the number of microbial phyla associated with this process. Eight of the twelve newly identified groups are candidate phyla that lack isolated representatives, a finding only possible given genomes from metagenomes. Two candidate phyla, Candidatus Rokubacteria and Candidatus Hydrothermarchaeota contain the earliest evolved genes. The capacity for sulfate reduction has been laterally transferred in multiple events within some phyla, and a key gene potentially capable of switching sulfur oxidation to sulfate reduction in associated cells has been acquired by putatively symbiotic bacteria. We conclude that functional predictions based on phylogeny will significantly underestimate the extent of sulfate reduction across Earth’s ecosystems. Understanding the prevalence of this capacity is integral to interpreting the carbon cycle because sulfate reduction is often coupled to turnover of buried organic carbon. Our findings expand the diversity of microbial groups associated with sulfur transformations in the environment and motivate revision of biogeochemical process models based on microbial community composition.

scholarly journals Pseudodesulfovibrio cashew sp. Nov., a Novel Deep-Sea Sulfate-Reducing Bacterium, Linking Heavy Metal Resistance and Sulfur Cycle

2021 ◽  
Vol 9 (2) ◽  
pp. 429
Author(s):  
Rikuan Zheng ◽  
Shimei Wu ◽  
Chaomin Sun
Keyword(s):  
Heavy Metal ◽  
Sulfate Reduction ◽  
Marine Sediments ◽  
Deep Sea ◽  
Sulfur Cycle ◽  
Metal Sulfides ◽  
Phenotypic Traits ◽  
Dissimilatory Sulfate Reduction ◽  
Metabolic Potential ◽  
Sulfate Reducing

Sulfur cycling is primarily driven by sulfate reduction mediated by sulfate-reducing bacteria (SRB) in marine sediments. The dissimilatory sulfate reduction drives the production of enormous quantities of reduced sulfide and thereby the formation of highly insoluble metal sulfides in marine sediments. Here, a novel sulfate-reducing bacterium designated Pseudodesulfovibrio cashew SRB007 was isolated and purified from the deep-sea cold seep and proposed to represent a novel species in the genus of Pseudodesulfovibrio. A detailed description of the phenotypic traits, phylogenetic status and central metabolisms of strain SRB007 allowed the reconstruction of the metabolic potential and lifestyle of a novel member of deep-sea SRB. Notably, P. cashew SRB007 showed a strong ability to resist and remove different heavy metal ions including Co2+, Ni2+, Cd2+ and Hg2+. The dissimilatory sulfate reduction was demonstrated to contribute to the prominent removal capability of P. cashew SRB007 against different heavy metals via the formation of insoluble metal sulfides.

scholarly journals Effects of Iron and Nitrogen Limitation on Sulfur Isotope Fractionation during Microbial Sulfate Reduction

2012 ◽  
Vol 78 (23) ◽  
pp. 8368-8376 ◽  
Author(s):  
Min Sub Sim ◽  
Shuhei Ono ◽  
Tanja Bosak
Keyword(s):  
Nitrogen Fixation ◽  
Sulfate Reduction ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Isotope Effects ◽  
Reducing Power ◽  
Sulfate Reducing ◽  
Microbial Sulfate Reduction ◽  
Sulfur Isotope Fractionation ◽  
S Isotope

ABSTRACTSulfate-reducing microbes utilize sulfate as an electron acceptor and produce sulfide that is depleted in heavy isotopes of sulfur relative to sulfate. Thus, the distribution of sulfur isotopes in sediments can trace microbial sulfate reduction (MSR), and it also has the potential to reflect the physiology of sulfate-reducing microbes. This study investigates the relationship between the availability of iron and reduced nitrogen and the magnitude of S-isotope fractionation during MSR by a marine sulfate-reducing bacterium, DMSS-1, aDesulfovibriospecies, isolated from salt marsh in Cape Cod, MA. Submicromolar levels of iron increase sulfur isotope fractionation by about 50% relative to iron-replete cultures of DMSS-1. Iron-limited cultures also exhibit decreased cytochromec-to-total protein ratios and cell-specific sulfate reduction rates (csSRR), implying changes in the electron transport chain that couples carbon and sulfur metabolisms. When DMSS-1 fixes nitrogen in ammonium-deficient medium, it also produces larger fractionation, but it occurs at faster csSRRs than in the ammonium-replete control cultures. The energy and reducing power required for nitrogen fixation may be responsible for the reverse trend between S-isotope fractionation and csSRR in this case. Iron deficiency and nitrogen fixation by sulfate-reducing microbes may lead to the large observed S-isotope effects in some euxinic basins and various anoxic sediments.

scholarly journals Expanded Genomic Sampling of the Desulfobulbales Reveals Distribution and Evolution of Sulfur Metabolisms

2021 ◽  
Author(s):  
Lewis M. Ward ◽  
Emma Bertran ◽  
David T. Johnston
Keyword(s):  
Sulfate Reduction ◽  
Sulfur Metabolism ◽  
Phylogenetic Analyses ◽  
Genomic Diversity ◽  
Test Case ◽  
Sulfur Disproportionation ◽  
Sulfate Reducing ◽  
Relative Contribution ◽  
Microbial Sulfate Reduction ◽  
Reducing Bacteria

AbstractThe reconstruction of modern and paleo-sulfur cycling relies on understanding the long-term relative contribution of its main actors; these include microbial sulfate reduction (MSR) and microbial sulfur disproportionation (MSD). However, a unifying theory is lacking for how MSR and MSD, with the same enzyme machinery and intimately linked evolutionary histories, perform two drastically different metabolisms. Here, we aim at shedding some light on the distribution, diversity, and evolutionary histories of MSR and MSD, with a focus on the Desulfobulbales as a test case. The Desulfobulbales is a diverse and widespread order of bacteria in the Desulfobacterota (formerly Deltaproteobacteria) phylum primarily composed of sulfate reducing bacteria. Recent culture- and sequence-based approaches have revealed an expanded diversity of organisms and metabolisms within this clade, including the presence of obligate and facultative sulfur disproportionators. Here, we present draft genomes of previously unsequenced species of Desulfobulbales, substantially expanding the available genomic diversity of this clade. We leverage this expanded genomic sampling to perform phylogenetic analyses, revealing an evolutionary history defined by vertical inheritance of sulfur metabolism genes with numerous convergent instances of transition from sulfate reduction to sulfur disproportionation.

Symbiosis and competition among sulfate reduction, filamentous sulfur, denitrification, and poly-p accumulation bacteria in the anaerobic-oxic activated sludge of a municipal plant

1996 ◽  
Vol 34 (5-6) ◽  
pp. 119-128 ◽  
Author(s):  
Ryoko Yamamoto-Ikemoto ◽  
Saburo Matsui ◽  
Tomoaki Komori ◽  
E. J. Bosque-Hamilton
Keyword(s):  
Organic Acids ◽  
Activated Sludge ◽  
Sulfate Reduction ◽  
Sulfide Oxidation ◽  
Sulfate Reducing Bacteria ◽  
Sulfur Cycle ◽  
Sulfate Reducing ◽  
P Accumulation ◽  
Relationship Of ◽  
Reducing Bacteria

Symbiosis and competition were examined among sulfate reducing bacteria (SRB), filamentous sulfur bacteria (FSB), denitrification bacteria (DNB) and poly-P accumulation bacteria (PAB) in the activated sludge of a municipal plant operated under anaerobic-oxic conditions. Batch experiments were carried out using settled sewage from the same plant as the substrate under several conditions. Under oxic conditions, both sulfate reduction and sulfide oxidation occurred simultaneously, making a symbiotic relationship of SRB and FSB for establishment of a sulfur cycle sustaining the energy requirements. Under anoxic conditions, denitrification was dominant because DNB outcompeted PAB and SRB for organic acids. Under anaerobic conditions, phosphate release and sulfate reduction occurred simultaneously. SRB produced for moles of acetate from four moles of propionate and/or unknown substances by reduction of three moles of sulfate. PAB competed with sulfate-reducing bacteria for organic acids such as propionate. However, PAB utilized acetate produced by SRB.

scholarly journals Microbial Sulfur Cycle in Two Hydrothermal Chimneys on the Southwest Indian Ridge

mBio ◽  
2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Huiluo Cao ◽  
Yong Wang ◽  
On On Lee ◽  
Xiang Zeng ◽  
Zongze Shao ◽  
...  
Keyword(s):  
Microbial Community ◽  
Sulfur Oxidation ◽  
Sulfur Cycle ◽  
Southwest Indian Ridge ◽  
Sulfate Reducing ◽  
Sulfur Oxidizing ◽  
Indian Ridge ◽  
Midocean Ridge ◽  
Reducing Bacteria ◽  
Hydrothermal Fields

ABSTRACT Sulfur is an important element in sustaining microbial communities present in hydrothermal vents. Sulfur oxidation has been extensively studied due to its importance in chemosynthetic pathways in hydrothermal fields; however, less is known about sulfate reduction. Here, the metagenomes of hydrothermal chimneys located on the ultraslow-spreading Southwest Indian Ridge (SWIR) were pyrosequenced to elucidate the associated microbial sulfur cycle. A taxonomic summary of known genes revealed a few dominant bacteria that participated in the microbial sulfur cycle, particularly sulfate-reducing Deltaproteobacteria. The metagenomes studied contained highly abundant genes related to sulfur oxidation and reduction. Several carbon metabolic pathways, in particular the Calvin-Benson-Bassham pathway and the reductive tricarboxylic acid cycles for CO2 fixation, were identified in sulfur-oxidizing autotrophic bacteria. In contrast, highly abundant genes related to the oxidation of short-chain alkanes were grouped with sulfate-reducing bacteria, suggesting an important role for short-chain alkanes in the sulfur cycle. Furthermore, sulfur-oxidizing bacteria were associated with enrichment for genes involved in the denitrification pathway, while sulfate-reducing bacteria displayed enrichment for genes responsible for hydrogen utilization. In conclusion, this study provides insights regarding major microbial metabolic activities that are driven by the sulfur cycle in low-temperature hydrothermal chimneys present on an ultraslow midocean ridge. IMPORTANCE There have been limited studies on chimney sulfides located at ultraslow-spreading ridges. The analysis of metagenomes of hydrothermal chimneys on the ultraslow-spreading Southwest Indian Ridge suggests the presence of a microbial sulfur cycle. The sulfur cycle should be centralized within a microbial community that displays enrichment for sulfur metabolism-related genes. The present study elucidated a significant role of the microbial sulfur cycle in sustaining an entire microbial community in low-temperature hydrothermal chimneys on an ultraslow spreading midocean ridge, which has characteristics distinct from those of other types of hydrothermal fields.

Stimulation of Dissimilatory Sulfate Reduction in Response to Sulfate in Microcosm Incubations from Two Contrasting Temperate Peatlands near Ithaca, NY, USA

2021 ◽  
Author(s):  
Andrew R St James ◽  
Ruth E Richardson
Keyword(s):  
Sulfate Reduction ◽  
Electron Donor ◽  
Short Chain Fatty Acids ◽  
Sulfur Cycle ◽  
Carbon Flow ◽  
Dissimilatory Sulfate Reduction ◽  
Metagenomic Sequencing ◽  
Community Responses ◽  
Sulfate Reducing ◽  
Stimulation Of

Abstract Peatlands are responsible for over half of wetland methane emissions, yet major uncertainties remain regarding carbon flow, especially when increased availability of electron acceptors stimulate competing physiologies. We used microcosm incubations to study the effects of sulfate on microorganisms in two temperate peatlands, one bog and one fen. Three different electron donor treatments were used (13C-acetate, 13C-formate, and a mixture of 12C short-chain fatty acids) to elucidate the responses of sulfate-reducing bacteria (SRB) and methanogens to sulfate stimulation. Methane production was measured and metagenomic sequencing was performed, with only the heavy DNA fraction sequenced from treatments receiving 13C electron donors. Our data demonstrate stimulation of dissimilatory sulfate reduction in both sites, with contrasting community responses. In McLean Bog (MB), hydrogenotrophic Deltaproteobacteria and acetotrophic Peptococcaceae lineages of SRB were stimulated, as were lineages with unclassified dissimilatory sulfite reductases. In Michigan Hollow Fen (MHF), there was little stimulation of Peptococcaceae populations, and a small stimulation of Deltaproteobacteria SRB populations only in the presence of formate as electron donor. Sulfate stimulated an increase in relative abundance of reads for both oxidative and reductive sulfite reductases, suggesting stimulation of an internal sulfur cycle. Together, these data indicate a stimulation of SRB activity in response to sulfate in both sites, with a stronger growth response in MB than MHF. This study provides valuable insights into microbial community responses to sulfate in temperate peatlands and is an important first step to understanding how SRB and methanogens compete to regulate carbon flow in these systems.

scholarly journals Active microbial sulfate reduction in fluids of serpentinizing peridotites of the continental subsurface

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Clemens Glombitza ◽  
Lindsay I. Putman ◽  
Kaitlin R. Rempfert ◽  
Michael D. Kubo ◽  
Matthew O. Schrenk ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Dna Sequences ◽  
Low Molecular Weight ◽  
Coast Range ◽  
Sulfate Reducing ◽  
Microbial Sulfate Reduction ◽  
High Fluid ◽  
Low Levels ◽  
Sulfate Reduction Rates ◽  
Strong Control

AbstractSerpentinization of peridotites in Earth’s mantle is associated with the generation of hydrogen and low molecular weight organics that could support subsurface life. Studies of microbial metabolisms in peridotite-hosted environments have focused primarily on methanogenesis, yet DNA sequences, isotopic composition of sulfides and thermodynamic calculations suggest there is potential for microbial sulfate reduction too. Here, we use a sulfate radiotracer-based method to quantify microbial sulfate reduction rates in serpentinization fluids recovered from boreholes in the Samail Ophiolite, Oman and the California Coast Range Ophiolite, USA. We find that low levels of sulfate reduction occur at pH up to 12.3. These low levels could not be stimulated by addition of hydrogen, methane or small organic acids, which indicates that this metabolism is limited by factors other than substrate availability. Cellular activity drops at pH > 10.5 which suggests that high fluid pH exerts a strong control on sulfate-reducing organisms in peridotites.

scholarly journals Anaerobic processes in activated sludge

1998 ◽  
Vol 37 (4-5) ◽  
pp. 605-608 ◽  
Author(s):  
Dirk de Beer ◽  
Andreas Schramm ◽  
Cecilia M. Santegoeds ◽  
Helle K. Nielsen
Keyword(s):  
Activated Sludge ◽  
Sulfate Reduction ◽  
Sulfide Oxidation ◽  
Sulfur Cycle ◽  
Operating Conditions ◽  
Anoxic Conditions ◽  
Sulfate Reducing ◽  
Tracer Techniques ◽  
Sulfate Reduction Rates ◽  
Anoxic Zones

We found anoxic zones in aerated activated sludge flocs, and demonstrated denitrification under normal operating conditions. Sulfate reduction was not found. Micro-environments and microbial conversions in flocs from bulking and non-bulking activated sludge were determined with microsensors for H2S, O2, NO2− and NO3−. Denitrification and sulfate reduction rates were mmeasured with 15N- and 35S-tracer techniques. We showed that under normal reactor conditions (ca. 20% air saturation) anoxic zones develop within flocs allowing denitrification. The denitrification rates amounted to 40% of the rates under anoxic conditions. At 100% air saturation no anoxic zones were found and no denitrification occurred. However, in flocs from bulking sludge (at 20% air saturation) anoxic zones were absent and denitrification did not occur. In bulking sludge only at total anoxia was denitrification found. Confocal microscopy showed that flocs from bulking sludge were much looser than those from non-bulking sludge. The absence of anoxic zones and of denitrification was attributed to the open floc structure, allowing advective oxygen transport. Sulfate reduction was not detected in any of the sludges tested by microsensors or by tracer techniques even under anoxic conditions. this indicates that the sulfur cycle (sulfate reduction and sulfide oxidation) does not play a role in mineralization processes and bulking in activated sludge. Preliminary molecular work (in situ hybridization with the 16S-rRNA probe SRB385) indicated the presence of small amounts of sulfate reducing bacteria in all sludges. Either the probe is not specific or the sulfate reducers present are not active under reactor conditions.

Control of filamentous bulking and interactions among sulfur oxidation-reduction and iron oxidation-reduction in activated sludge using an iron coagulant

1998 ◽  
Vol 38 (8-9) ◽  
pp. 9-17 ◽  
Author(s):  
Ryoko Yamamoto-Ikemoto ◽  
Saburo Matsui ◽  
Tomoaki Komori ◽  
Edja Kofi Bosque-Hamilton
Keyword(s):  
Activated Sludge ◽  
Sulfate Reduction ◽  
Iron Oxidation ◽  
Sulfur Oxidation ◽  
Phosphate Removal ◽  
Aeration Tank ◽  
Filamentous Bulking ◽  
Sulfate Reducing ◽  
Oxidation Reduction ◽  
Reducing Bacteria

The effect of iron coagulant on control of filamentous bulking and phosphate removal was investigated using a laboratory scale activated sludge process. Sulfate reduction was correlated to activated sludge bulking. When FeCl2 was added to the aeration tank, most of the phosphate was removed. Sulfate reduction and filamentous bulking were also suppressed. The addition of FeCl2 was also effective in suppressing phosphate release and sulfide production from wasted sludge. Interactions among sulfur oxidation-reduction and iron oxidation-reduction were examined in the batch experiments. When FeCl2 was added, iron reducing bacteria outcompeted sulfate reducing bacteria and iron oxidizing bacteria grew predominantly.

scholarly journals Accelerated Sulfur Cycle in Coastal Marine Sediment beneath Areas of Intensive Shellfish Aquaculture

2005 ◽  
Vol 71 (6) ◽  
pp. 2925-2933 ◽  
Author(s):  
Hiroki Asami ◽  
Masato Aida ◽  
Kazuya Watanabe
Keyword(s):  
Sulfur Oxidation ◽  
Sulfur Cycle ◽  
Rrna Gene ◽  
Shellfish Aquaculture ◽  
Sulfate Reducing ◽  
Oxidation Rates ◽  
Coastal Marine ◽  
Culture Independent ◽  
Molecular Phylogenetic ◽  
Coastal Marine Sediment

ABSTRACT Prokaryotes in marine sediments taken from two neighboring semienclosed bays (the Yamada and Kamaishi bays) at the Sanriku coast in Japan were investigated by the culture-independent molecular phylogenetic approach coupled with chemical and activity analyses. These two bays were chosen in terms of their similar hydrogeological and chemical characteristics but different usage modes; the Yamada bay has been used for intensive shellfish aquaculture, while the Kamaishi bay has a commercial port and is not used for aquaculture. Substantial differences were found in the phylogenetic composition of 16S rRNA gene clone libraries constructed for the Yamada and Kamaishi sediments. In the Yamada library, phylotypes affiliated with δ-Proteobacteria were the most abundant, and those affiliated with γ-Proteobacteria were the second-most abundant. In contrast, the Kamaishi library was occupied by phylotypes affiliated with Planctomycetes, γ-Proteobacteria, δ-Proteobacteria, and Crenarchaeota. In the γ-Proteobacteria, many Yamada phylotypes were related to free-living and symbiotic sulfur oxidizers, whereas the Kamaishi phylotype was related to the genus Pseudomonas. These results allowed us to hypothesize that sulfate-reducing and sulfur-oxidizing bacteria have become abundant in the Yamada sediment. This hypothesis was supported by quantitative competitive PCR (qcPCR) with group-specific primers. The qcPCR also suggested that organisms closely related to Desulfotalea in the Desulfobulbaceae were the major sulfate-reducing bacteria in these sediments. In addition, potential sulfate reduction and sulfur oxidation rates in the sediment samples were determined, indicating that the sulfur cycle has become active in the Yamada sediment beneath the areas of intensive shellfish aquaculture.

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