scholarly journals Effects of Dissolved Sulfide, pH, and Temperature on Growth and Survival of Marine Hyperthermophilic Archaea

2005 ◽  
Vol 71 (10) ◽  
pp. 6383-6387 ◽  
Author(s):  
Karen G. Lloyd ◽  
Virginia P. Edgcomb ◽  
Stephen J. Molyneaux ◽  
Simone Böer ◽  
Carl O. Wirsen ◽  
...  
Keyword(s):  
Hydrothermal Vent ◽  
Carbon Sources ◽  
Low Ph ◽  
Electron Donors ◽  
Hyperthermophilic Archaea ◽  
Sulfide Concentration ◽  
Growth And Survival ◽  
Dissolved Sulfide ◽  
Close Relatives ◽  
High Sulfide

ABSTRACT The ability of metabolically diverse hyperthermophilic archaea to withstand high temperatures, low pHs, high sulfide concentrations, and the absence of carbon and energy sources was investigated. Close relatives of our study organisms, Methanocaldococcus jannaschii, Archaeoglobus profundus, Thermococcus fumicolans, and Pyrococcus sp. strain GB-D, are commonly found in hydrothermal vent chimney walls and hot sediments and possibly deeper in the subsurface, where highly dynamic hydrothermal flow patterns and steep chemical and temperature gradients provide an ever-changing mosaic of microhabitats. These organisms (with the possible exception of Pyrococcus strain GB-D) tolerated greater extremes of low pH, high sulfide concentration, and high temperature when actively growing and metabolizing than when starved of carbon sources and electron donors/acceptors. Therefore these organisms must be actively metabolizing in the hydrothermal vent chimneys, sediments, and subsurface in order to withstand at least 24 h of exposure to extremes of pH, sulfide, and temperature that occur in these environments.

scholarly journals Mechanisms of passivation and chloride-induced corrosion of mild steel in sulfide-containing alkaline solutions

2021 ◽  
Author(s):  
Shishir Mundra ◽  
John L. Provis
Keyword(s):  
Mild Steel ◽  
Surface Film ◽  
Critical Role ◽  
Chloride Concentration ◽  
Alkaline Solutions ◽  
Sulfide Concentration ◽  
Chloride Induced Corrosion ◽  
Alkaline Sulfide ◽  
High Sulfide

AbstractThe pore fluid within many concretes is highly alkaline and rich in reduced sulfur species, but the influence of such alkaline-sulfide solutions on the surface film formed on steel reinforcement is poorly understood. This study investigates the critical role of HS− in defining mild steel passivation chemistry. The surface film formed on the steel in alkaline-sulfide solutions contains Fe(OH)2 and Fe–S complexes, and the critical chloride concentration to induce corrosion increases at high sulfide concentration. However, this behavior is dependent on the duration of exposure of the steel to the electrolyte, and the nature of the sulfidic surface layer.

scholarly journals Freshwater Chlorobia Exhibit Metabolic Specialization among Cosmopolitan and Endemic Populations

mSystems ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Sarahi L. Garcia ◽  
Maliheh Mehrshad ◽  
Moritz Buck ◽  
Jackson M. Tsuji ◽  
Josh D. Neufeld ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Carbon Sources ◽  
Natural Populations ◽  
Freshwater Ecosystems ◽  
Electron Donors ◽  
Functional Ecology ◽  
Lake Ecosystems ◽  
Tropical Regions ◽  
Metabolic Versatility ◽  
Globally Distributed

ABSTRACT Photosynthetic bacteria from the class Chlorobia (formerly phylum Chlorobi) sustain carbon fixation in anoxic water columns. They harvest light at extremely low intensities and use various inorganic electron donors to fix carbon dioxide into biomass. Until now, most information on the functional ecology and local adaptations of Chlorobia members came from isolates and merely 26 sequenced genomes that may not adequately represent natural populations. To address these limitations, we analyzed global metagenomes to profile planktonic Chlorobia cells from the oxyclines of 42 freshwater bodies, spanning subarctic to tropical regions and encompassing all four seasons. We assembled and compiled over 500 genomes, including metagenome-assembled genomes (MAGs), single-amplified genomes (SAGs), and reference genomes from cultures, clustering them into 71 metagenomic operational taxonomic units (mOTUs or “species”). Of the 71 mOTUs, 57 were classified within the genus Chlorobium, and these mOTUs represented up to ∼60% of the microbial communities in the sampled anoxic waters. Several Chlorobium-associated mOTUs were globally distributed, whereas others were endemic to individual lakes. Although most clades encoded the ability to oxidize hydrogen, many lacked genes for the oxidation of specific sulfur and iron substrates. Surprisingly, one globally distributed Scandinavian clade encoded the ability to oxidize hydrogen, sulfur, and iron, suggesting that metabolic versatility facilitated such widespread colonization. Overall, these findings provide new insight into the biogeography of the Chlorobia and the metabolic traits that facilitate niche specialization within lake ecosystems. IMPORTANCE The reconstruction of genomes from metagenomes has helped explore the ecology and evolution of environmental microbiota. We applied this approach to 274 metagenomes collected from diverse freshwater habitats that spanned oxic and anoxic zones, sampling seasons, and latitudes. We demonstrate widespread and abundant distributions of planktonic Chlorobia-associated bacteria in hypolimnetic waters of stratified freshwater ecosystems and show they vary in their capacities to use different electron donors. Having photoautotrophic potential, these Chlorobia members could serve as carbon sources that support metalimnetic and hypolimnetic food webs.

scholarly journals Evaluation of Biogas Biodesulfurization Using Different Packing Materials

2019 ◽  
Vol 3 (1) ◽  
pp. 27 ◽  
Author(s):  
Samir Tayar ◽  
Renata Guerrero ◽  
Leticia Hidalgo ◽  
Denise Bevilaqua
Keyword(s):  
Material Selection ◽  
Low Cost ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Packing Material ◽  
Sulfide Concentration ◽  
Packing Materials ◽  
Selection For ◽  
High Sulfide

The packing material selection for a bioreactor is an important factor to consider, since the characteristics of this material can directly affect the performance of the bioprocess, as well as the investment costs. Different types of low cost packing materials were studied in columns to reduce the initial and operational costs of biogas biodesulfurization. The most prominent (PVC pieces from construction pipes) was applied in a bench-scale biotrickling filter to remove the H2S of the biogas from a real sewage treatment plant in Brazil, responsible for 90 thousand inhabitants. At the optimal experimental condition, the reactor presented a Removal Efficiency (RE) of up to 95.72% and Elimination Capacity (EC) of 98 gS·m−3·h−1, similar to open pore polyurethane foam, the traditional material widely used for H2S removal. These results demonstrated the high potential of application of this packing material in a full scale considering the robustness of the system filled with this support, even when submitted to high sulfide concentration, fluctuations in H2S content in biogas, and temperature variations.

scholarly journals Physiology of Geobacter metallireducens under excess and limitation of electron donors. Part I. Batch cultivation with excess of carbon sources

2014 ◽  
Vol 37 (4) ◽  
pp. 277-286 ◽  
Author(s):  
Sviatlana Marozava ◽  
Wilfred F.M. Röling ◽  
Jana Seifert ◽  
Robert Küffner ◽  
Martin von Bergen ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Batch Cultivation ◽  
Electron Donors ◽  
Geobacter Metallireducens

scholarly journals Glutamate Decarboxylase-Mediated Nisin Resistance in Listeria monocytogenes

2010 ◽  
Vol 76 (19) ◽  
pp. 6541-6546 ◽  
Author(s):  
Máire Begley ◽  
Paul D. Cotter ◽  
Colin Hill ◽  
R. Paul Ross
Keyword(s):  
Listeria Monocytogenes ◽  
Glutamate Decarboxylase ◽  
Low Ph ◽  
Specific Inhibition ◽  
General Phenomenon ◽  
Growth And Survival ◽  
Gram Positive Bacteria ◽  
Complete Set ◽  
Gad Activity ◽  
Is Strain

ABSTRACT Analysis of a complete set of glutamate decarboxylase (gad) mutants of Listeria monocytogenes strain LO28 (ΔgadD1, ΔgadDT1, ΔgadD2, ΔgadT2, and ΔgadD3 mutants) revealed that the ΔgadD1 mutant is impaired in its ability to tolerate exposure to both sublethal and lethal levels of the lantibiotic nisin. gadD1 is strain variable and is found only in approximately 50% of L. monocytogenes strains. Growth and survival experiments revealed that possession of gadD1 correlates with a higher degree of tolerance to nisin. Significantly, a similar finding using a gadB mutant of L. lactis IL1403 implies that this may be a general phenomenon in Gram-positive bacteria. Our findings thus suggest that the specific inhibition of GAD activity or a reduction in the levels of free glutamate may prevent the growth of otherwise resistant GAD+ bacteria in foods where low pH and/or nisin is used as a preservative.

Recent findings on sinks for sulfide in gravity sewer networks

2006 ◽  
Vol 54 (6-7) ◽  
pp. 127-134 ◽  
Author(s):  
A.H. Nielsen ◽  
T. Hvitved-Jacobsen ◽  
J. Vollertsen
Keyword(s):  
Large Diameter ◽  
Sulfide Oxidation ◽  
Sulfur Cycle ◽  
Metal Sulfides ◽  
Sulfide Concentration ◽  
Dissolved Sulfide ◽  
Gravity Sewer ◽  
Large Diameter Pipes ◽  
Steep Slopes ◽  
Sewer Networks

Sulfide buildup in sewer networks is associated with several problems, including health impacts, corrosion of sewer structures and odor nuisance. In recent years, significant advances in the knowledge of the major processes governing sulfide buildup in sewer networks have been made. This paper summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However, sulfide emission and thereby potential hydrogen sulfide buildup in the sewer atmosphere is of particular importance in sewers constructed with large diameter pipes, in sewers constructed with steep slopes and in sewers conveying low pH wastewater. Precipitation of metal sulfides is only important when the sulfide concentration in the wastewater is low; i.e. less than 1 g S m−3.

scholarly journals Contrasting patterns of bacterial communities in the rearing water and gut of Penaeus vannamei in response to exogenous glucose addition

2022 ◽  
Author(s):  
Lei Huang ◽  
Haipeng Guo ◽  
Zidan Liu ◽  
Chen Chen ◽  
Kai Wang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bacterial Communities ◽  
Carbon Sources ◽  
Operational Taxonomic Unit ◽  
Diversity Indices ◽  
Response Patterns ◽  
Interspecies Interactions ◽  
Glucose Addition ◽  
Growth And Survival ◽  
Α Diversity

AbstractSupplementing exogenous carbon sources is a practical approach to improving shrimp health by manipulating the microbial communities of aquaculture systems. However, little is known about the microbiological processes and mechanisms of these systems. Here, the effects of glucose addition on shrimp growth performance and bacterial communities of the rearing water and the shrimp gut were investigated to address this knowledge gap. The results showed that glucose addition significantly improved the growth and survival of shrimp. Although the α-diversity indices of both bacterioplankton communities and gut microbiota were significantly decreased by adding glucose, both bacterial communities exhibited divergent response patterns to glucose addition. Glucose addition induced a dispersive bacterioplankton community but a more stable gut bacterial community. Bacterial taxa belonging to Ruegeria were significantly enriched by glucose in the guts, especially the operational taxonomic unit 2575 (OTU2575), which showed the highest relative importance to the survival rate and individual weight of shrimp, with the values of 43.8 and 40.6%, respectively. In addition, glucose addition increased the complexity of interspecies interactions within gut bacterial communities and the network nodes from Rhodobacteraceae accounted for higher proportions and linked more with the nodes from other taxa in the glucose addition group than that in control. These findings suggest that glucose addition may provide a more stable gut microbiota for shrimp by increasing the abundance of certain bacterial taxa, such as Ruegeria.

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