Originally isolated from the biomass of an Alvinella pompejana episymbiont community collected at 13 degrees N along the East Pacific Rise Axial Caldera ...
A novel thermophilic, acidophilic bacterium, designated strain Pd55T, was isolated from a self-temperature-recording in situ colonization system deployed in a hydrothermal diffusing flow (maximum temperature of 78 °C) at the TOTO caldera in the Mariana Arc. Cells of strain Pd55T were motile, short rods with a single polar flagellum. Growth was observed between 30 and 68 °C (optimum growth at 50 °C; 120 min doubling time) and between (initial) pH 4·2 and 7·0 (optimum at pH 5·2). The isolate was a strictly anaerobic chemolithoautotroph capable of using molecular hydrogen as sole energy source and carbon dioxide as sole carbon source. Elemental sulfur served as the sole electron acceptor to support growth. The G+C content of the genomic DNA was 34·0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate was related to members of the genera Nautilia and Caminibacter, although it appeared to be a novel lineage prior to the divergence between Nautilia and Caminibacter.
The Prokaryotes is a comprehensive, multi-authored, peer reviewed reference work on Bacteria and Achaea. This fourth edition of The Prokaryotes is organized to cover all taxonomic diversity, using the family level to delineate chapters.Different from other resources, this new Springer product
Stolz JF, Ellis DJ, Blum JS, Ahmann D, Lovley DR, Oremland RS. 1999. Sulfurospirillum barnesii sp. nov. and Sulfurospirillum arsenophilum sp. nov., new members of the Sulfurospirillum clade of the epsilon Proteobacteria.. Int J Syst Bacteriol. 49 Pt 3:1177-80. ...
Grote, R., Li, L., Tamaoka, J., Kato, C., Horikoshi, K., and Antranikian, G. Thermococcus siculi sp. nov., a novel hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent at the mid-Okinawa Trough. Extremophiles (1999) 3:55-62 ...
Lineage: cellular organisms; Bacteria; Proteobacteria; delta/epsilon subdivisions; Epsilonproteobacteria; Campylobacterales; Helicobacteraceae; Sulfurimonas; unclassified ...
Lineage: cellular organisms; Bacteria; Proteobacteria; delta/epsilon subdivisions; Epsilonproteobacteria; Campylobacterales; Helicobacteraceae; Helicobacter; Helicobacter ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
ID A7GYC3_CAMC5 Unreviewed; 347 AA. AC A7GYC3; DT 11-SEP-2007, integrated into UniProtKB/TrEMBL. DT 11-SEP-2007, sequence version 1. DT 22-NOV-2017, entry version 82. DE RecName: Full=D-alanine--D-alanine ligase {ECO:0000256,SAAS:SAAS00910572}; DE EC=6.3.2.4 {ECO:0000256,SAAS:SAAS00910572}; GN Name=ddlA {ECO:0000313,EMBL:EAT99804.1}; GN ORFNames=CCV52592_1152 {ECO:0000313,EMBL:EAT99804.1}; OS Campylobacter curvus (strain 525.92). OC Bacteria; Proteobacteria; Epsilonproteobacteria; Campylobacterales; OC Campylobacteraceae; Campylobacter. OX NCBI_TaxID=360105 {ECO:0000313,EMBL:EAT99804.1, ECO:0000313,Proteomes:UP000006380}; RN [1] {ECO:0000313,Proteomes:UP000006380} RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=525.92 {ECO:0000313,Proteomes:UP000006380}; RA Fouts D.E., Mongodin E.F., Puiu D., Sebastian Y., Miller W.G., RA Mandrell R.E., Lastovica A.J., Nelson K.E.; RT "Genome sequence of Campylobacter curvus 525.92 isolated from human RT feces."; RL Submitted (JUL-2007) to the ...
... and plants that can convert visible light into chemi- cal energy. In addition, chemoautotrophic bacteria can produce organic molecules from CO2 in the ab- sence of light. They use ...
Filamentous microbial mats from three aphotic sulfidic springs in Lower Kane Cave, Wyoming, were assessed with regard to bacterial diversity, community structure influenced by geochemical changes, and ecosystem function using a 16S rDNA-based phylogenetic approach combined with elemental content and carbon and sulfur stable isotope ratio analyses. The bulk of the microbial mats had carbon isotope values (mean ?13C = -34.7‰, 1? = 3.6) consistent with chemolithoautotrophic carbon fixation from a dissolved inorganic carbon reservoir (cave water, mean ?13C = -7.4‰; n = 8). The most widespread mat morphotype consisted of white filament bundles, with low C:N ratios (3.5-5.4) and high sulfur content (16.1-51.2%). Bacterial diversity was low overall, and the most prevalent taxonomic group was affiliated with the "Epsilonproteobacteria" (68%); six genetically distinct epsilonproteobacterial groups were identified. Other bacterial sequences were affiliated with Gammaproteobacteria (12.2%), ...
Microbial activity in produced water from hydraulic fracturing operations can lead to undesired environmental impacts and increase gas production costs. However, the metabolic profile of these microbial communities is not well understood. Here, for the first time, we present results from a shotgun metagenome of microbial communities in both hydraulic fracturing source water and wastewater produced by hydraulic fracturing. Taxonomic analyses showed an increase in anaerobic/facultative anaerobic classes related to Clostridia, Gammaproteobacteria, Bacteroidia and Epsilonproteobacteria in produced water as compared to predominantly aerobic Alphaproteobacteria in the fracturing source water. Thus, the metabolic profile revealed a relative increase in genes responsible for carbohydrate metabolism, respiration, sporulation and dormancy, iron acquisition and metabolism, stress response and sulfur metabolism in the produced water samples. These results suggest that microbial communities in produced water ...
Effective publication: KUEVER (J.), RAINEY (F.A.) and WIDDEL (F.): Order VI. Syntrophobacterales ord. nov. In: D.J. BRENNER, N.R. KRIEG, J.T. STALEY and G. M. GARRITY (editors), Bergeys Manual of Systematic Bacteriology, second edition, vol. 2 (The Proteobacteria), part C (The Alpha-, Beta-, Delta-, and Epsilonproteobacteria), Springer, New York, 2005, p. 1021 ...
A system for use in storing biopharmaceutical materials includes a holder and a container for holding biopharmaceutical materials therein. The container includes a storage portion and a sampling portion connected to each other by a connecting portion. The holder has a storage cavity receiving the storage portion and a sampling cavity receiving the sampling portion. The holder includes a first portion and second portion. The container is received between the first portion and the second portion to connect the container to the holder. The holder includes an interior storage cradle bounding the storage cavity of the holder. The holder includes an interior sampling cradle bounding the sampling cavity. The sampling cradle is separated from the storage cradle and connected to the storage cradle by a passage receiving the connecting portion connecting the storage portion to the sampling portion. An outer rim of the holder is connected to the cradle and separated from the cavity.
Deep in the ocean, bizarre creatures colonize deep-sea hydrothermal vents, where boiling water laden with minerals builds otherworldly towers.
Prokaryotic communities forming symbiotic relationships with the vent shrimp, Rimicaris exoculata, are well studied components of hydrothermal ecosystems at the Mid-Atlantic Ridge (MAR). Despite the tight link between host and symbiont, the observed lack of spatial genetic structure seen in R. exoculata contrasts with the geographic differentiation detected in specific bacterial ectosymbionts. The geographic clustering of bacterial lineages within a seemingly panmictic host suggests either the presence of finer scale restriction to gene flow not yet detected in the host, horizontal transmission (environmental selection) of its endosymbionts as a consequence of unique vent geochemistry, or vertically transmitted endosymbionts that exhibit genetic differentiation ...
The Mariana region exhibits a rich array of hydrothermal venting conditions in a complex geological setting, which provides a natural laboratory to study the influence of local environmental conditions on microbial community structure as well as large-scale patterns in microbial biogeography. We used high-throughput amplicon sequencing of the bacterial small subunit (SSU) rRNA gene from 22 microbial mats collected from four hydrothermally active locations along the Mariana Arc and back-arc to explore the structure of lithotrophically-based microbial mat communities. The vent effluent was classified as iron- or sulfur-rich corresponding with two distinct community types, dominated by either Zetaproteobacteria or Epsilonproteobacteria, respectively. The Zetaproteobacterial-based communities had the highest richness and diversity, which supports the hypothesis that Zetaproteobacteria are ecosystem engineers creating a physical habitat within a chemical environment promoting enhanced microbial diversity. In
The hydrothermal vent zoarcid fish Thermarces cerberus is a top predator that inhabits deep-sea hydrothermal vents on the East Pacific Rise (EPR). Bacterial chemoautotrophy at these sites supports abundant animal communities. Paradoxically, these chemoautotrophic bacteria are not known to produce polyunsaturated fatty acids (PUFA), dietary nutrients essential for all marine vertebrates. To understand how T cerberus successfully exploits the vent environment and obtains essential PUFA, we compared its fatty acid composition to those of its invertebrate prey. Levels of 20 : 5(n - 3) and 22 : 6(n - 3) in muscle and ovary tissues of T. cerberus were low and contained higher amounts of 20 : 5(n - 3) than 22 : 6(n - 3). This is in contrast to most marine fish where 22 : 6(n - 3) typically dominates. Prey items include the limpet (Lepetodrilus elevates) and amphipods (Halice hesmonectes and Ventiella sulfuris) and all contained PUFA dominated by 20: 5(n - 3) in amounts likely to support the ...
The deep-sea hypersaline anoxic basins (DHABs) of the Mediterranean (water depth ~3500 m) are some of the most extreme oceanic habitats known. Brines of DHABs are nearly saturated with salt, leading many to suspect they are uninhabitable for eukaryotes. While diverse bacterial and protistan communities are reported from some DHAB haloclines and brines, loriciferans are the only metazoan reported to inhabit the anoxic DHAB brines. Our goal was to further investigate metazoan communities in DHAB haloclines and brines. We report observations from sediments of three DHAB (Urania, Discovery, LAtalante) haloclines, comparing these to observations from sediments underlying normoxic waters of typical Mediterranean salinity. Due to technical difficulties, sampling of the brines was not possible. Morphotype analysis indicates nematodes are the most abundant taxon; crustaceans, loriciferans and bryozoans were also noted. Among nematodes, Daptonema was the most abundant genus; three morphotypes were noted with a
Results of a numerical modeling study of quartz dissolution and precipitation in a sub-seafloor hydrothermal system have been used to predict where in the system quartz could be deposited and potentially trap fluid inclusions. The spatial distribution of zones of quartz dissolution and precipitation is complex, owing to the fact that quartz solubility depends on many inter-related factors, including temperature, fluid salinity and fluid immiscibility, and is further complicated by the fact that quartz exhibits both prograde and retrograde solubility behavior, depending on the fluid temperature and salinity. Using the PVTX properties of H2O-NaCl, the petrographic and microthermometric properties of fluid inclusions trapped at various locations within the hydrothermal system have been predicted. Vapor-rich inclusions are trapped as a result of the retrograde temperature-dependence of quartz solubility as the convecting fluid is heated in the vicinity of the magmatic heat source. Coexisting ...
Our mobile solution prepare seawater for Hydraulic Fracturing, reducing the scaling potential coming from filtered seawater and formation water.
Mono- and Stereopictres of 5.0 Angstrom coordination sphere of Copper atom in PDB 3f7l: X-Ray Crystal Structure of Alvinella Pompejana Cu,Zn Superoxide Dismutase
Organic substances in produced and formation water from coalbed methane (CBM) and gas shale plays from across the USA were examined in this study. Disposal of produced waters from gas extraction in coal and shale is an important environmental issue because of the large volumes of water involved and the variable quality of this water. Organic substances in produced water may be environmentally relevant as pollutants, but have been little studied. Results from five CBM plays and two gas shale plays (including the Marcellus Shale) show a myriad of organic chemicals present in the produced and formation water. Organic compound classes present in produced and formation water in CBM plays include: polycyclic aromatic hydrocarbons (PAHs), heterocyclic compounds, alkyl phenols, aromatic amines, alkyl aromatics (alkyl benzenes, alkyl biphenyls), long-chain fatty acids, and aliphatic hydrocarbons. Concentrations of individual compounds range from | 1 to 100 μg/L, but total PAHs (the dominant compound...
Organohalide-respiring microorganisms can use a variety of persistent pollutants including trichloroethene (TCE) as terminal electron acceptors. The final two-electron transfer step in organohalide respiration is catalyzed by reductive dehalogenases. Here we report the x-ray crystal structure of PceA, an archetypal dehalogenase from Sulfurospirillum multivorans, as well as structures of PceA in complex with TCE and product analogs. The active site harbors a deeply buried norpseudo-B12 cofactor within a nitroreductase fold, also found in a mammalian B12 chaperone. The structures of PceA reveal how a cobalamin supports a reductive haloelimination exploiting a conserved B12-binding scaffold capped by a highly variable substrate-capturing region.. ...
ID CAMJJ_2_PE1054 STANDARD; PRT; 441 AA. AC CAMJJ_2_PE1054; A1W082; DT 00-JAN-0000 (Rel. 1, Created) DT 00-JAN-0000 (Rel. 2, Last sequence update) DT 00-JAN-0000 (Rel. 3, Last annotation update) DE SubName: Full=Apolipoprotein N-acyltransferase; EC=2.3.1 -; DE (CAMJJ_2.PE1054). GN Name=cutE; OrderedLocusNames=CJJ81176_1113; OS CAMPYLOBACTER JEJUNI SUBSP. JEJUNI 81-176. OC Bacteria; Proteobacteria; Epsilonproteobacteria; Campylobacterales; OC Campylobacteraceae; Campylobacter. OX NCBI_TaxID=354242; RN [0] RP -.; RG -.; RL -.; CC -!- SEQ. DATA ORIGIN: Translated from the HOGENOM CDS CAMJJ_2.PE1054. CC Campylobacter jejuni subsp. jejuni 81-176, complete genome. CC complete sequence. CC -!- ANNOTATIONS ORIGIN:A1W082_CAMJJ CC -!- FUNCTION: Transfers the fatty acyl group on membrane lipoproteins CC (By similarity). CC -!- PATHWAY: Protein modification; lipoprotein biosynthesis (N-acyl CC transfer). CC -!- SUBCELLULAR LOCATION: Cell inner membrane; Multi-pass membrane CC protein (By similarity). CC -!- ...
Watabe, H. & Hashimoto, J. 2002. A new species of the genus Rimicaris (Alvinocarididae: Caridea: Decapoda) from the active hydrothermal vent field, "Kairei Field", on the Central Indian Ridge, the Indian Ocean. Zoological science 19: 1167-1174. PDF ...
Charlou JL, Donval JP, Konn C, Ondréas H, Fouquet Y, Jean-Baptiste P & Fourré E (2010) High production and fluxes of H2 and CH4 and evidence of abiotic hydrocarbon synthesis by serpentinization in ultramafic-hosted hydrothermal systems on the Mid-Atlantic Ridge. Diversity of Hydrothermal Systems on Slow-Spreading Ocean Ridges, Vol. 188 (Rona P, Devey C, Dyment J & Murton B, eds), pp. 265-296. American Geophysical Union, Washington, DC ...
We investigated the impact of temperature on the microbial turnover of organic matter (OM) in a hydrothermal vent system in Guaymas Basin, by calculating microbial bio- and necromass turnover times based on the culture-independent D:L-amino acid model. Sediments were recovered from two stations near hydrothermal mounds (8 to 106 cells cm-3 within ∼5 m of sediment depth resulting in a 100-fold lower cell number at this depth than at the cold site where numbers remained constant at 108 cells cm-3 throughout the recovered sediment. There were strong indications that the drop in cell abundance was controlled by decreasing OM quality. The quality of the sedimentary OM was determined by the diagenetic indicators %TAAC (percentage of total organic carbon present as amino acid carbon), %TAAN (percentage of total nitrogen present as amino acid nitrogen), aspartic acid:β-alanine ratios, and glutamic acid:γ-amino butyric acid ratios. All parameters indicated that the OM became progressively degraded with
Elicitation of Antibiotic Natural Products in Multispecies Cultures of Deep-Sea Vent-Derived Microorganisms (2014-2016)Kerry McPhailCollege of PharmacyOregon State University203 Pharmacy BuildingCorvallis, Oregon 97331Phone: 541-737-5808EmailCo-PI: Aleksandra Sikora, OSU
Alviniconcha strummeri, a deep-sea snail that lives in an extreme environment regardless of what its parents think, reminded the authors of a new study ...
The flow of formation waters in these strata is driven by gravity (topography) and erosional rebound, and is controlled by rock absolute permeability, gas generation and capillary pressure to gas (relative permeability). The gas content of the coal ... Show Abstract ...
Tunnicliffe, V., Baross, J., Gebruk, A., Giere, O., Koschinsky, A., Reysenbach, A.L., Shank, T.M., and Summit, M. (2003): Group report 3: What are the interactions between biotic processes a vents and physical, chemical and geological conditions? In: Report of the Dahlem Workshop on Energy and Mass Transfer in Hydrothermal Systems. October 2001 (Eds. P. Halbach, V. Tunnicliffe, and J.R. Hein, 251-270 ...
Buy Adjustable Louvre Vent Air Vents at Screwfix.com. 30 day money back guarantee. Free next day delivery available. 60 days free credit available. The UK
Enrichment cultures are investigated for the bioremediation potential of tetrachloroethene (PCE). This process is based on anaerobic respiration in which chlorinated compounds are used as electron acceptors (organohalide respiration, OHR). The key enzyme in OHR is the reductive dehalogenase (RdhA). SL2, a culture dechlorinating PCE to harmless ethene, was shown to have a small number of OHR bacteria, mainly Sulfurospirillum spp. and Dehalococcoides spp. (1). Aim: We aim at a better understanding of the functional diversity of rdhA genes in the SL2 culture and their dynamic during PCE degradation. Methods: By applying different frequencies of culture transfer, 3 sub-cultures were obtained from the SL2 enrichment showing different degradation patterns. The degradation profile was followed by gas chromatography and chloride titration. DNA and RNA were also extracted, PCR and qPCR was performed for the detection of rdhA genes belonging to Sulfurospirillum. Besides, a T-RFLP method was developed to ...
The anaerobic oxidation of methane (AOM) is a globally significant sink that regulates methane flux from sediments into the oceans and atmosphere. Here we examine mesophilic to thermophilic AOM in hydrothermal sediments recovered from the Middle Valley vent field, on the Juan de Fuca Ridge. Using continuous-flow sediment bioreactors and batch incubations, we characterized (i) the degree to which AOM contributes to net dissolved inorganic carbon flux, (ii) AOM and sulfate reduction (SR) rates as a function of temperature and (iii) the distribution and density of known anaerobic methanotrophs (ANMEs). In sediment bioreactors, inorganic carbon stable isotope mass balances results indicated that AOM accounted for between 16% and 86% of the inorganic carbon produced, underscoring the role of AOM in governing inorganic carbon flux from these sediments. At 90°C, AOM occurred in the absence of SR, demonstrating a striking decoupling of AOM from SR. An abundance of Fe(III)-bearing minerals resembling ...
Get information, facts, and pictures about Hydrothermal systems (Geology) at Encyclopedia.com. Make research projects and school reports about Hydrothermal systems (Geology) easy with credible articles from our FREE, online encyclopedia and dictionary.
Get information, facts, and pictures about hydrothermal vent at Encyclopedia.com. Make research projects and school reports about hydrothermal vent easy with credible articles from our FREE, online encyclopedia and dictionary.
Microbial diversity in a submarine carbonate edifice from the serpentinized hydrothermal system of the Prony Bay (New Caledonia) over 6-year period ...
Water sampling is a critical process to understanding the reactions taking place at Lost City. (Quicktime, 1.7 Mb). An important goal of our expedition is to better understand how the reactions of the basement rocks influence the chemistry of the fluids and hydrothermal chimney growth. Secondly, how do these fluids provide nutrients for biological communities in and around the vent structures? Unlike black smoker hydrothermal systems, the rocks underneath Lost City originate from the Earths mantle and have been transported from great depths - typically greater than about 6 kilometers below the seafloor. Large faults have exposed these mantle rocks on the seafloor, and when seawater reacts with them, new minerals - in particular the mineral serpentine - are formed, and heat is produced. This process, referred to as serpentinization, is an important reaction occurring where mantle rocks are exposed near the seafloor and is what drives the Lost City hydrothermal system. Another consequence of ...
Scientists exploring the black waters around a deep-sea vent have discovered a bacterium that can convert light into energy. This is the first discovery of an organism that uses a source of light, other than the sun, in the process of photosynthesis.
One of the recurring questions with hydrothermal vent animals is that given that the vents are so separated, how do the animals living at them disperse from vent to vent? The paper alludes that that when it discusses the relationships between the shrimps in this genus. The geographic locations of the species dont seem to make well with the relationships, which would be consistent with animals that have to disperse widely and live in short-lived habitats ...
Definition of Vent ones spleen with photos and pictures, translations, sample usage, and additional links for more information.
This pipe marking label is for ammonia pipes and specifically the thermosyphon vent. It can be placed directly on the pipe for easy reading.
lol! Dont worry, we wont think shes into that, just you. just kidding! BTW I saw this article and thought maybe this is where you will be one day with someone discovering your toon and making a film ...
2019 m. spalio 20 d., Kupi kyje, Uogini k. automobili kroso trasoje vyks V Kupi kio auto-moto sportas organizuojama 2019 m. automobili sporto sezono u darymo vent ...
Were finding deep-sea vents more rapidly than ever before," says expedition leader Professor Paul Tyler of the University of Southamptons School of Ocean and Earth Science, which is based at the National Oceanography Centre, Southampton. "And were finding some in places other than at mid-ocean ridges, where most have been seen before.". By studying the new vents, the team hope to understand more about the distribution and evolution of life in the deep ocean, the role that deep-sea vents play in controlling the chemistry of the oceans, and the diversity of microbes that thrive in different conditions beneath the waves.. The researchers were exploring Adventure Caldera, a crater-like hole in the seafloor three kilometres across and 750 metres deep at its deepest point. Despite its size, Adventure Caldera was only discovered last year by geophysicists from the British Antarctic Survey.. ...
Biogeochemical Interactions at Deep-Sea Vents Working Group Update 2008 N. Le Bris, Working Group Chair Members The WG for Biogeochemical Interactions at Deep-Sea Vents had one new change in membership for 2008. Huaiyang Zhou has joined the IR WG for Deep-Earth Sampling, and we invited Xiqiu Han (Second Institute of Oceanography, China) to join our WG in replacement. Xiqius expertise in oxygen and carbon isotopic signatures of chemosynthetic processes fits perfectly with the WG objectives, and she will bring a complementary view from China.. ...
General Information: This organism is a colorless sulfur-oxidizing bacterium isolated from a deep-sea hydrothermal vent. Sulfur-oxidizing bacterium. Thiomicrospira crunogena is a chemoautotroph commonly isolated from deep sea and shallow-water hydrothermal vents. This organism uses the oxidation of reduced sulfur compounds (thiosulfate, sulfide and sulfur) to generate the energy necessary to fix carbon and plays an important role in the cycling of sulfur in the marine environment. ...
Haverkamp, Thomas Hendricus Augustus & Nesbø, Camilla Lothe (2014). Comparative analysis of genome methylation in Thermotogae isolates from deep-sea hydrothermal vents. Show summary Recent advances in single-molecule, real-time (SMRT) sequecing has made it possible to detected methylated bases in bacterial genomes. This method detects different types of DNA methylation while simulatously identify putative recognition sequences fro the methyltranserase proteins. Common prokaryotic base modifications are N4-methylcytosine (m4C), 5-meth- ylcytosine (m5c) and N6-methyladenine (m6A). Here we use SMRT sequencing to compare the m4C and m6A genomic methylation pattern of four Thermotogae isolates from deep-sea hydrothermal vents; Thermosipho melanesiensis 431, Marinitoga sp. strain 1137 and Thermosipho sp. strains 1063 and 1070. The members of the bacterial phylum Thermotogae can be found in ecosystems with hyperthermic to mesothermic conditions such as oilfields and hydrothermal vents.. ...
ABSTRACT: Vertical distributions of viable (most probable number, MPN) aerobic chemoautotrophic thiobacilli-like sulfur-oxidizing bacteria (ca. 70 samples in triplicate for MPN counts) and dark 14C-bicarbonate incorporation rates were analyzed in a series of sulfide-rich lakes. A special device for sampling sharply stratified populations on the scale of a few centimeters was used. Detailed analyses focused on the oxic-anoxic transition zone where aerobic sulfur-oxidizing bacteria should display positive chemotaxis, and in both fully oxic epilimnia and sulfide-rich anoxic hypolimnia. Kinetics of sulfide and thiosulfate potential oxidations in the presence of oxygen were followed in microcosm enrichments in one of the lakes. The highest MPN counts (,104 to 105 cells ml-1) were observed at the oxic-anoxic interfaces and in the depleted hypolimnia (1.3 ± 4.4 × 104 cells ml-1), whereas 1 order of magnitude lower concentrations were detected in the epilimnia (1.0 ± 2.3× 103 cells ml-1). Dark ...