Metagenome-assembled Genomes Related to Ammoniaoxidizing Thaumarchaeota Recovered from Near-anoxic Environment

Abstract Meromictic lakes are interesting ecosystems to study anaerobic microorganisms due their permanent stratification allowing the formation of a stable anoxic environment. The crenogenic meromictic Lake Cadagno harbors an important community of anoxygenic phototrophic sulfur bacteria responsible for almost half of its total productivity. Besides their ability to fix CO2 through photosynthesis, these microorganisms also showed high rates of dark carbon fixation via chemosyntesis. Here, we grew in pure cultures three populations of anoxygenic phototrophic sulfur bacteria previously isolated from the lake, accounting for 72.8% of the total microbial community, and exibiting different phenotypes: 1) the motile, large-celled purple sulfur bacterium (PSB) Chromatium okenii, 2) the small-celled PSB Thiodictyon syntrophicum, and 3) the green sulfur bacterium (GSB) Chlorobium phaeobacteroides. We measured their ability to fix CO2 through photo- and chemo-synthesis, both in situ in the lake and in laboratory under different incubation conditions. We also evaluated the efficiency and velocity of H2S photo-oxidation, an important reaction in the anoxygenic photosynthesis process. Our results confirm that phototrophic sulfur bacteria strongly fix CO2 in the presence of light and that oxygen increases chemosynthesis at night, in laboratory conditions. Moreover, substancial differences were displayed between the three selected populations in terms of activity and abundance.

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Simultaneous removal of BOD, N and P in a single continuous flow real scale activated sludge reactor with cyclic aeration

Water Practice & Technology ◽

10.2166/wpt.2020.012 ◽

2020 ◽

Vol 15 (1) ◽

pp. 201-212

Author(s):

Álvaro Orozco-Jaramillo ◽

Santiago Vélez-Velásquez

Keyword(s):

Continuous Flow ◽

Treatment Plant ◽

Domestic Wastewater ◽

Aeration Tank ◽

Domestic Wastewater Treatment ◽

Stable Conditions ◽

Activated Sludge Reactor ◽

Anoxic Environment ◽

Real Scale ◽

Composite Samples

Abstract The present study evaluates the performance of a real scale domestic wastewater treatment plant (WWTP), operating under continuous flow conditions with ‘extremely high sludge age’, designed to remove organic matter and perform nitrification-denitrification within a single reactor under cyclic aeration. Composite samples were withdrawn from the reactor for one week and their analysis results compared satisfactorily with the calculations of the design models. The WWTP is operating under stable conditions with a BOD5 removal of 86%, COD removal of 87%, TKN removal of 73% and, unexpectedly, a stable removal of 55% of total phosphorus. The design of the WWTP is simple and consists of a single aeration tank with a kinetic selector and a secondary sedimentation tank, operating under cyclic conditions in the aeration tank, with 45-minute aeration on (oxic environment) and 15 minutes aeration off (anoxic environment). The system can be applied to upgrade WWTP from secondary to tertiary treatment with only small modifications. A phosphorus removal mechanism is also proposed.

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Oxygenated Mesoproterozoic lake revealed through magnetic mineralogy

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1813493115 ◽

2018 ◽

Vol 115 (51) ◽

pp. 12938-12943 ◽

Cited By ~ 13

Author(s):

Sarah P. Slotznick ◽

Nicholas L. Swanson-Hysell ◽

Erik A. Sperling

Keyword(s):

Iron Oxide ◽

Intermediate Water ◽

Low Oxygen ◽

Mineral Assemblages ◽

Oxygen Conditions ◽

Terrestrial Environments ◽

Anoxic Environment ◽

Nuanced Understanding ◽

Textural Analyses ◽

Shed Light

Terrestrial environments have been suggested as an oxic haven for eukaryotic life and diversification during portions of the Proterozoic Eon when the ocean was dominantly anoxic. However, iron speciation and Fe/Al data from the ca. 1.1-billion-year-old Nonesuch Formation, deposited in a large lake and bearing a diverse assemblage of early eukaryotes, are interpreted to indicate persistently anoxic conditions. To shed light on these distinct hypotheses, we analyzed two drill cores spanning the transgression into the lake and its subsequent shallowing. While the proportion of highly reactive to total iron (FeHR/FeT) is consistent through the sediments and typically in the range taken to be equivocal between anoxic and oxic conditions, magnetic experiments and petrographic data reveal that iron exists in three distinct mineral assemblages resulting from an oxycline. In the deepest waters, reductive dissolution of iron oxides records an anoxic environment. However, the remainder of the sedimentary succession has iron oxide assemblages indicative of an oxygenated environment. At intermediate water depths, a mixed-phase facies with hematite and magnetite indicates low oxygen conditions. In the shallowest waters of the lake, nearly every iron oxide has been oxidized to its most oxidized form, hematite. Combining magnetics and textural analyses results in a more nuanced understanding of ambiguous geochemical signals and indicates that for much of its temporal duration, and throughout much of its water column, there was oxygen in the waters of Paleolake Nonesuch.

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The Cogollo Group and the oceanic anoxic events 1a and 1b, Maracaibo basin, Venezuela

Brazilian Journal of Geology ◽

10.1590/2317-4889201530192 ◽

2015 ◽

Vol 45 (suppl 1) ◽

pp. 41-61 ◽

Cited By ~ 4

Author(s):

José Alejandro Méndez Dot ◽

José Méndez Baamonde ◽

Dayana Reyes ◽

Rommel Whilchy

Keyword(s):

Source Rock ◽

Organic Geochemistry ◽

Sedimentary Facies ◽

Source Rocks ◽

Maracaibo Basin ◽

Pelagic Environment ◽

Anoxic Events ◽

Anoxic Environment ◽

Platform System ◽

La Luna

ABSTRACTCarbonates of Cogollo Group (Apón, Lisure and Maraca formations) constitute the broader calcareous platform system originated during Aptian and Albian of Cretaceous in north-western South America, Maracaibo Basin, Venezuela. On the shallow shelf, a variety of calcareous sedimentary facies were deposited during marine transgressive and regressive cycles. Some of them developed porosity and constitute important hydrocarbon reservoirs. Due to some major marine transgressions, from early Aptian, the anoxic environment and characteristic facies of a pelagic environment moved from the outer slope and basin to the shallow shelf, during specific time intervals, favouring the sedimentation of organic matter-rich facies, which correspond to the oceanic anoxic events (OAEs) 1a and 1b. The source rock of Machiques Member (Apón Formation) was deposited during early Aptian OAE 1a (~ 120 Ma). The source rock of Piché Member, located at the top of the Apón Formation, was deposited during late Aptian OAE 1b (~ 113 Ma). Finally, La Luna Formation, from Cenomanian, that covers the OAE 2 (~ 93 Ma), represents the most important source rock in the Maracaibo Basin. In this way and based on sedimentological and organic geochemistry results from the determinations performed on 247 samples belonging to six cores in the Maracaibo Basin, we propose these two organic-rich levels, deposited on the shallow shelf of the Cogollo Group, as "effective source rocks", additional to La Luna Formation, with oil migration in relatively small distances to the porosity facies.

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Feasibility of nanoscale zero-valent iron loaded sediment-based biochar (nZVI-SBC) for simultaneous removal of nitrate and phosphate: high selectivity towards dinitrogen and synergistic mechanism

10.21203/rs.3.rs-222879/v1 ◽

2021 ◽

Author(s):

Xiaohui Liu ◽

Jia Wei ◽

Liangang Hou ◽

Yuhan Zhu ◽

Yaodong Wu ◽

...

Keyword(s):

High Selectivity ◽

Phosphate Removal ◽

Zero Valent Iron ◽

Polluted Water ◽

Nitrogen And Phosphorus ◽

Nanoscale Zero Valent Iron ◽

Synergistic Mechanism ◽

Loading Ratio ◽

Anoxic Environment ◽

Complexation Mechanism

Abstract In the process of water treatment, excessive nitrogen and phosphorus pollutants are of great concern. Therefore, we prepared nanoscale zero-valent iron loaded on sediment-based biochar (nZVI-SBC) to conduct nitrate and phosphate removal at the same time. The characterization demonstrated that nZVI-SBC was successfully synthesized, which had obvious advantages for larger specific surface area and better dispersion compared with pure nZVI. The batch experiments indicated that the best loading ratio of nZVI to SBC and optimum dosage for nitrate and phosphate were 1:1and 2 g·L-1, respectively. Their removal by nZVI-SBC was an acid-driven process. Anoxic environment was more conducive to the reduction of nitrate while the phosphate removal was fond of oxygen environment. 77.78% of nitrate and 99.21% of phosphate have been successfully removed, mainly depending on reduction and complexation mechanism, respectively. Moreover, nZVI-SBC had higher N2 selectivity and produced less ammonium than nZVI. The interaction between nitrate and phosphate was studied to manifest that they had different degrees of inhibition during the removal of the other. Our research indicated that nZVI-SBC has great potential for remediation of nitrogen and phosphorus polluted water.

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Assessment of Lipid Compounds in Anoxic Environment from Conceição Lagoon, Santa Catarina Island, Brazil

Revista Virtual de Química ◽

10.5935/1984-6835.20120036 ◽

2012 ◽

Vol 4 (4) ◽

Author(s):

Giovana A. Bataglion ◽

Patricia Puhl ◽

Martinho Rau ◽

Sandra Regina Damatto ◽

Luiz Augusto dos S. Madureira

Keyword(s):

Santa Catarina ◽

Anoxic Environment ◽

Lipid Compounds

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Artificial consortium demonstrates emergent properties of enhanced cellulosic-sugar degradation and biofuel synthesis

npj Biofilms and Microbiomes ◽

10.1038/s41522-020-00170-8 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Heejoon Park ◽

Ayushi Patel ◽

Kristopher A. Hunt ◽

Michael A. Henson ◽

Ross P. Carlson

Keyword(s):

Biomass Productivity ◽

Biomass Accumulation ◽

Vertical Axis ◽

Feedback Mechanism ◽

Emergent Properties ◽

Cellulolytic Enzyme ◽

E Coli ◽

Secondary Resource ◽

Sugar Degradation ◽

Anoxic Environment

AbstractPlanktonic cultures, of a rationally designed consortium, demonstrated emergent properties that exceeded the sums of monoculture properties, including a >200% increase in cellobiose catabolism, a >100% increase in glycerol catabolism, a >800% increase in ethanol production, and a >120% increase in biomass productivity. The consortium was designed to have a primary and secondary-resource specialist that used crossfeeding with a positive feedback mechanism, division of labor, and nutrient and energy transfer via necromass catabolism. The primary resource specialist was Clostridium phytofermentans (a.k.a. Lachnoclostridium phytofermentans), a cellulolytic, obligate anaerobe. The secondary-resource specialist was Escherichia coli, a versatile, facultative anaerobe, which can ferment glycerol and byproducts of cellobiose catabolism. The consortium also demonstrated emergent properties of enhanced biomass accumulation when grown as biofilms, which created high cell density communities with gradients of species along the vertical axis. Consortium biofilms were robust to oxic perturbations with E. coli consuming O2, creating an anoxic environment for C. phytofermentans. Anoxic/oxic cycling further enhanced biomass productivity of the biofilm consortium, increasing biomass accumulation ~250% over the sum of the monoculture biofilms. Consortium emergent properties were credited to several synergistic mechanisms. E. coli consumed inhibitory byproducts from cellobiose catabolism, driving higher C. phytofermentans growth and higher cellulolytic enzyme production, which in turn provided more substrate for E. coli. E. coli necromass enhanced C. phytofermentans growth while C. phytofermentans necromass aided E. coli growth via the release of peptides and amino acids, respectively. In aggregate, temporal cycling of necromass constituents increased flux of cellulose-derived resources through the consortium. The study establishes a consortia-based, bioprocessing strategy built on naturally occurring interactions for improved conversion of cellulose-derived sugars into bioproducts.

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TNT biodegradation and production of dihydroxylamino-nitrotoluene by aerobic TNT degrader Pseudomonas sp. strain TM15 in an anoxic environment

Biodegradation ◽

10.1007/s10532-008-9182-6 ◽

2008 ◽

Vol 19 (6) ◽

pp. 795-805 ◽

Cited By ~ 9

Author(s):

Akira Kubota ◽

Toshinari Maeda ◽

Nobuaki Nagafuchi ◽

Kiwao Kadokami ◽

Hiroaki I. Ogawa

Keyword(s):

Pseudomonas Sp ◽

Anoxic Environment

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Determinants of hypoxia-inducible factor activity in the intestinal mucosa

Journal of Applied Physiology ◽

10.1152/japplphysiol.00203.2017 ◽

2017 ◽

Vol 123 (5) ◽

pp. 1328-1334 ◽

Cited By ~ 4

Author(s):

Raphael R. Fagundes ◽

Cormac T. Taylor

Keyword(s):

Intestinal Mucosa ◽

Inflammatory Responses ◽

Inflammatory Diseases ◽

Hypoxia Inducible Factor ◽

Oxygen Demand ◽

Intestinal Lumen ◽

Adaptation To Hypoxia ◽

Healthy Mucosa ◽

Microenvironmental Factors ◽

Anoxic Environment

The intestinal mucosa is exposed to fluctuations in oxygen levels due to constantly changing rates of oxygen demand and supply and its juxtaposition with the anoxic environment of the intestinal lumen. This frequently results in a state of hypoxia in the healthy mucosa even in the physiologic state. Furthermore, pathophysiologic hypoxia (which is more severe and extensive) is associated with chronic inflammatory diseases including inflammatory bowel disease (IBD). The hypoxia-inducible factor (HIF), a ubiquitously expressed regulator of cellular adaptation to hypoxia, is central to both the adaptive and the inflammatory responses of cells of the intestinal mucosa in IBD patients. In this review, we discuss the microenvironmental factors which influence the level of HIF activity in healthy and inflamed intestinal mucosae and the consequences that increased HIF activity has for tissue function and disease progression.

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