| beggiatoa, thiothrix, and thioploca. | | 1983 | 6357055 |
| dense populations of a giant sulfur bacterium in namibian shelf sediments. | a previously unknown giant sulfur bacterium is abundant in sediments underlying the oxygen minimum zone of the benguela current upwelling system. the bacterium has a spherical cell that exceeds by up to 100-fold the biovolume of the largest known prokaryotes. on the basis of 16s ribosomal dna sequence data, these bacteria are closely related to the marine filamentous sulfur bacteria thioploca, abundant in the upwelling area off chile and peru. similar to thioploca, the giant bacteria oxidize sul ... | 1999 | 10205058 |
| nitrogen, carbon, and sulfur metabolism in natural thioploca samples | filamentous sulfur bacteria of the genus thioploca occur as dense mats on the continental shelf off the coast of chile and peru. since little is known about their nitrogen, sulfur, and carbon metabolism, this study was undertaken to investigate their (eco)physiology. thioploca is able to store internally high concentrations of sulfur globules and nitrate. it has been previously hypothesized that these large vacuolated bacteria can oxidize sulfide by reducing their internally stored nitrate. we e ... | 1999 | 10388716 |
| phylogenetic relationships of a large marine beggiatoa. | based upon 16s rrna sequence and phenotypic similarities, a large, uncultured beggiatoa sp. from the bay of concepción (chile), is very closely related to the chilean thioploca species thioploca araucae., whose filaments grow as sheathed bundles. the formation of sheathed filament bundles, the key character to distinguish the genus thioploca from beggiatoa, places closely related filamentous sulfur-oxidizing bacteria into two different genera, incongruent with 16s rrna-defined clades. | 1999 | 10188277 |
| the fine structure of thioploca ingrica and a comparison with beggiatoa. | | 1965 | 5861285 |
| filamentous bacteria inhabiting the sheaths of marine thioploca spp. on the chilean continental shelf. | a new component of the benthic thioploca mat microbial ecosystem on the chilean continental shelf was detected by epifluorescence microscopy: filamentous, bacterial endobionts of 4-5-mum filament diameter and length sometimes exceeding 1 mm. these filaments were identified as growing within thioploca sheaths located between the sediment surface and c. 5 cm depth. their location coincided with maximal biomass and biovolume of thioploca filaments in surficial sediments, and with maximal abundance ... | 2009 | 19573198 |
| [colorless sulfur bacteria thioploca from different sites in lake baikal]. | the colorless sulfur bacteria thioploca spp. found in lake baikal are probably a marker for the influx of subterranean mineralized fluids. bacteria act as a biological filter; by consuming sulfide in their metabolism, they detoxicate it and maintain the purity of lake baikal's water. the bacteria were investigated by various techniques. according to analysis of the 16s rrna gene fragment, thioploca sp. from frolikha bay, baikal belongs to the clade of freshwater species found in lake biwa and la ... | 2009 | 19334606 |
| physiology and behaviour of marine thioploca. | among prokaryotes, the large vacuolated marine sulphur bacteria are unique in their ability to store, transport and metabolize significant quantities of sulphur, nitrogen, phosphorus and carbon compounds. in this study, unresolved questions of metabolism, storage management and behaviour were addressed in laboratory experiments with thioploca species collected on the continental shelf off chile. the thioploca cells had an aerobic metabolism with a potential oxygen uptake rate of 1760 micromol o2 ... | 2009 | 19262616 |
| new communities of large filamentous sulfur bacteria in the eastern south pacific. | new complex communities of morphologically diverse and sometimes abundant large, multicellular, filamentous bacteria were discovered in the oxygen-deficient, organically laden, shelf sediments under the oxygen minimum zone off the coast of the eastern pacific, i.e., off the coasts of central and northern chile; central and northern perú; roca redonda, galápagos archipielago, ecuador; and off the pacific coasts of panamá and costa rica. similar microbial communities were also observed in the redu ... | 2007 | 17661287 |
| carbon source utilization and accumulation of respiration-related substances by freshwater thioploca species. | carbon source utilization of thioploca species from freshwater and brackish lakes in japan was investigated. microautoradiography demonstrated that freshwater and brackish thioploca samples assimilate acetate. in addition, vertical nitrate transportation by freshwater thioploca was examined by measuring substances accumulated in thioploca filaments. the filaments of thioploca sp. from lake biwa, a japanese mesotrophic lake, contained nitrate at concentrations higher than ambient by two to three ... | 2007 | 16989657 |
| community structure of bacteria associated with sheaths of freshwater and brackish thioploca species. | bacterial communities associated with sheaths of thioploca spp. from two freshwater lakes (lake biwa, japan, and lake constance, germany) and one brackish lake (lake ogawara, japan) were analyzed with denaturing gradient gel electrophoresis (dgge) of 16s rrna gene fragments. the comparison between the dgge band patterns of bulk sediment and thioploca filaments of lake biwa suggested the presence of specific bacterial communities associated with thioploca sheaths. as members of sheath-associated ... | 2006 | 16944341 |
| cultivated beggiatoa spp. define the phylogenetic root of morphologically diverse, noncultured, vacuolate sulfur bacteria. | within the last 10 years, numerous ssu rrna sequences have been collected from natural populations of conspicuous, vacuolate, colorless sulfur bacteria, which form a phylogenetically cohesive cluster (large-vacuolate sulfur bacteria clade) in the gamma-proteobacteria. currently, this clade is composed of four named or de facto genera: all known thioploca and thiomargarita strains, all vacuolate beggiatoa strains, and several strains of vacuolate, attached filaments, which bear a superficial simi ... | 2006 | 16788728 |
| vertical migration in the sediment-dwelling sulfur bacteria thioploca spp. in overcoming diffusion limitations. | in order to investigate the environmental requirements of the filamentous sulfur bacteria thioploca spp., we tested the chemotactic responses of these sedimentary microorganisms to changes in oxygen, nitrate, and sulfide concentrations. a sediment core with a thioploca mat, retrieved from the oxygen-minimum zone on the chilean shelf, was incubated in a recirculating flume. the addition of 25 (mu)mol of nitrate per liter to the seawater flow induced the ascent of the thioploca trichomes (length, ... | 1996 | 16535328 |
| community structure of filamentous, sheath-building sulfur bacteria, thioploca spp., off the coast of chile. | the filamentous sulfur bacteria thioploca spp. produce dense bacterial mats in the shelf area off the coast of chile and peru. the mat consists of common sheaths, shared by many filaments, that reach 5 to 10 cm down into the sediment. the structure of the thioploca communities off the bay of concepcion was investigated with respect to biomass, species distribution, and three-dimensional orientation of the sheaths. thioploca sheaths and filaments were found across the whole shelf area within the ... | 1996 | 16535327 |
| high nitrate concentrations in vacuolate, autotrophic marine beggiatoa spp. | massive accumulations of very large beggiatoa spp. are found at a monterey canyon cold seep and at guaymas basin hydrothermal vents. both environments are characterized by high sediment concentrations of soluble sulfide and low levels of dissolved oxygen in surrounding waters. these filamentous, sulfur-oxidizing bacteria accumulate nitrate intracellularly at concentrations of 130 to 160 mm, 3,000- to 4,000-fold higher than ambient levels. average filament widths range from 24 to 122 (mu)m, and i ... | 1996 | 16535282 |
| lipid biomarkers and carbon isotope signatures of a microbial (beggiatoa) mat associated with gas hydrates in the gulf of mexico. | white and orange mats are ubiquitous on surface sediments associated with gas hydrates and cold seeps in the gulf of mexico. the goal of this study was to determine the predominant pathways for carbon cycling within an orange mat in green canyon (gc) block gc 234 in the gulf of mexico. our approach incorporated laser-scanning confocal microscopy, lipid biomarkers, stable carbon isotopes, and 16s rrna gene sequencing. confocal microscopy showed the predominance of filamentous microorganisms (4 to ... | 2005 | 15812044 |
| novel, attached, sulfur-oxidizing bacteria at shallow hydrothermal vents possess vacuoles not involved in respiratory nitrate accumulation. | novel, vacuolate sulfur bacteria occur at shallow hydrothermal vents near white point, calif. there, these filaments are attached densely to diverse biotic and abiotic substrates and extend one to several centimeters into the surrounding environment, where they are alternately exposed to sulfidic and oxygenated seawater. characterizations of native filaments collected from this location indicate that these filaments possess novel morphological and physiological properties compared to all other v ... | 2004 | 15574952 |
| phylogenetic analysis of beggiatoa spp. from organic rich sediment of tokyo bay, japan. | nitrate-accumulating filamentous bacteria from organic rich sediment of tokyo bay, morphologically similar to beggiatoa species, were phylogenetically analyzed. from several sites in tokyo bay, beggiatoa-like bacteria were collected. each sample contained narrower or wider type (10 and 30 microns, respectively) of trichomes. with the nested pcr using specific primers for beggiatoa, fragments of 16s rrna gene were amplified and then subjected to denaturing gradient gel electrophoresis (dgge) anal ... | 2003 | 14509709 |
| rotifers colonising sediments with shallow gas hydrates. | rotifers, one of the smallest metazoans, are only seldom found in marine environments. surprisingly, we discovered high abundances of at least two new species of rotifers settling in anoxic and highly sulphidic sediments associated with shallow gas hydrates (gh) at the southern crest of hydrate ridge off oregon, ne pacific, in a water depth of about 780 m. at basins adjacent to hydrate ridge, 1,285-2,304 m deep, we found rotifers co-occurring with the sulphide-oxidising bacteria thioploca sp. | 2003 | 12835839 |
| phylogeny and distribution of nitrate-storing beggiatoa spp. in coastal marine sediments. | filamentous sulphide-oxidizing beggiatoa spp. often occur in large numbers in the coastal seabed without forming visible mats on the sediment surface. we studied the diversity, population structure and the nitrate-storing capability of such bacteria in the danish limfjorden and the german wadden sea. their distribution was compared to the vertical gradients of o2, no3- and h2s as measured by microsensors. the main beggiatoa spp. populations occurred in a 0.5-3 cm thick intermediate zone, below t ... | 2003 | 12755720 |
| morphological and phylogenetic characterizations of freshwater thioploca species from lake biwa, japan, and lake constance, germany. | filamentous, gliding, sulfide-oxidizing bacteria of the genus thioploca were found on sediments in profundal areas of lake biwa, a japanese freshwater mesotrophic lake, and were characterized morphologically and phylogenetically. the lake biwa thioploca resembled morphologically thioploca ingrica, a brackish water species from a danish fjord. the diameters of individual trichomes were 3 to 5.6 microm; the diameters of complete thioploca filaments ranged from 18 to 75 micro m. the cell lengths ra ... | 2003 | 12514020 |
| ecology of thioploca spp.: nitrate and sulfur storage in relation to chemical microgradients and influence of thioploca spp. on the sedimentary nitrogen cycle. | microsensors, including a recently developed no3(-) biosensor, were applied to measure o(2) and no3(-) profiles in marine sediments from the upwelling area off central chile and to investigate the influence of thioploca spp. on the sedimentary nitrogen metabolism. the studies were performed in undisturbed sediment cores incubated in a small laboratory flume to simulate the environmental conditions of low o(2), high no3(-), and bottom water current. on addition of no3(-) and no2(-), thioploca spp ... | 2001 | 11722903 |
| pathways of carbon oxidation in continental margin sediments off central chile. | rates and oxidative pathways of organic carbon mineralization were determined in sediments at six stations on the shelf and slope off concepcion bay at 36.5 degrees s. the depth distribution of c oxidation rates was determined to 10 cm from accumulation of dissolved inorganic c in 1-5-d incubations. pathways of c oxidation were inferred from the depth distributions of the potential oxidants (o2, no3-, and oxides of mn and fe) and from directly determined rates of so4(2-) reduction. the study are ... | 1996 | 11540503 |
| [ecophysiological features of mat-forming bacteria thioploca in bottom sediments of frolikha bay, northern baikal]. | a colorless sulfur bacterium of the genus thioploca, which forms bacterial mats, was studied in the region of underwater thermal vents (frolikha bay, northern baikal). the organism occurs under microaerobic conditions in top sediment layers, and its biomass can amount to 65 mg of wet weight per 1 kg of silt. individual filaments of the bacterium penetrate the anaerobic zone to the depth of 19 cm. thioploca is distributed in a mosaic pattern over the bottom of the bay. thioploca mats are typicall ... | 2001 | 11450463 |
| [microbiological processes of the carbon and sulfur cycle in cold methane seeps in the north atlantic]. | functioning of microbial communities in surface sediments of the haakon mosby underwater mud volcano (lat. 72 degrees n) and in gas seepage fields of the vestnesa ridge was investigated using mir-1 and mir-2 deep-sea submersibles during the 40th expedition of the research vessel academician mstislav keldysh. large areas of sedimentary deposits of the haakon mosby mud volcano (hmmv) and pockmarks of the vestnesa ridge (vr) are covered with bacterial mats 0.1 to 0.5 cm thick. the microbial communi ... | 2000 | 11195584 |
| physiology, phylogenetic relationships, and ecology of filamentous sulfate-reducing bacteria (genus desulfonema) | microscopy of organic-rich, sulfidic sediment samples of marine and freshwater origin revealed filamentous, multicellular microorganisms with gliding motility. many of these neither contained sulfur droplets such as the beggiatoa species nor exhibited the autofluorescence of the chlorophyll-containing cyanobacteria. a frequently observed morphological type of filamentous microorganism was enriched under anoxic conditions in the dark with isobutyrate plus sulfate. two strains of filamentous, glid ... | 1999 | 10525735 |
| thiomicrospira chilensis sp. nov., a mesophilic obligately chemolithoautotrophic sulfuroxidizing bacterium isolated from a thioploca mat. | a new member of the genus thiomicrospira, which utilizes thiosulfate as the electron donor and co2 as the carbon source, was isolated from a sediment sample dominated by the filamentous sulfur bacterium thioploca. although the physiological properties investigated are nearly identical to other described species of the genus, it is proposed that strain ch-1t is a member of a new species, thiomicrospira chilensis sp. nov., on the basis of differences in genotypic characteristics (16s rrna sequence ... | 1999 | 10319513 |
| vacuolated beggiatoa-like filaments from different hypersaline environments form a novel genus. | in this study, members of a specific group of thin (6-14 µm filament diameter), vacuolated beggiatoa-like filaments from six different hypersaline microbial mats were morphologically and phylogenetically characterized. therefore, enrichment cultures were established, filaments were stained with fluorochromes to show intracellular structures and 16s rrna genes were sequenced. morphological characteristics of beggiatoa-like filaments, in particular the presence of intracellular vacuoles, and the d ... | 2011 | 21651683 |
| distribution, ecology and molecular identification of thioploca from danish brackish water sediments. | the distribution of thioploca populations was investigated in danish fjords, brackish lakes and coastal waters. thioploca was found in three geographically distinct populations, where biomasses reached 33.8+/-14.3 g wet weight m(-2) (mean+/-sd). mats or lawns were not formed at the sediment surfaces and thioploca biomasses peaked 4-7 cm into the sediment and extended down to 18 cm depth. morphology and 16s rrna gene sequences classified all populations as thioploca ingrica. a sequence divergence ... | 2010 | 20455936 |
| a single-cell sequencing approach to the classification of large, vacuolated sulfur bacteria. | the colorless, large sulfur bacteria are well known because of their intriguing appearance, size and abundance in sulfidic settings. since their discovery in 1803 these bacteria have been classified according to their conspicuous morphology. however, in microbiology the use of morphological criteria alone to predict phylogenetic relatedness has frequently proven to be misleading. recent sequencing of a number of 16s rrna genes of large sulfur bacteria revealed frequent inconsistencies between th ... | 2011 | 21498017 |
| phylogenetic affinity of a wide, vacuolate, nitrate-accumulating beggiatoa sp. from monterey canyon, california, with thioploca spp. | environmentally dominant members of the genus beggiatoa and thioploca spp. are united by unique morphological and physiological adaptations (s. c. mchatton, j. p. barry, h. w. jannasch, and d. c. nelson, appl. environ. microbiol. 62:954-958, 1996). these adaptations include the presence of very wide filaments (width, 12 to 160 microm), the presence of a central vacuole comprising roughly 80% of the cellular biovolume, and the capacity to internally concentrate nitrate at levels ranging from 150 ... | 1999 | 9872789 |
| diversity of freshwater thioploca species and their specific association with filamentous bacteria of the phylum chloroflexi. | phylogenetic diversity among filamentous sulfur-oxidizing bacteria of the genus thioploca inhabiting freshwater/brackish environments was analyzed in detail. the 16s rrna gene sequence of thioploca found in a freshwater lake in japan, lake okotanpe, was identical to that of thioploca from lake ogawara, a brackish lake. the samples of the two lakes could be differentiated by the sequences of their 23s rrna genes and 16s-23s rrna internal transcribed spacer (its) regions. the 23s rrna-based phylog ... | 2011 | 21800088 |