The Experts below are selected from a list of 36132 Experts worldwide ranked by ideXlab platform
Ulrich Szewzyk - One of the best experts on this subject based on the ideXlab platform.
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Isolation of Sphaerotilus-Leptothrix strains from Iron Bacteria communities in Tierra del Fuego wetlands.
FEMS microbiology ecology, 2014Co-Authors: Bertram Schmidt, Leandro Arturo Sanchez, Till Fretschner, Gastón Kreps, Marcela Alejandra Ferrero, Faustino Siñeriz, Ulrich SzewzykAbstract:Sheath-forming Iron- and manganese-depositing Bacteria belonging to the Sphaerotilus–Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced Iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG Bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG Bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and Iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1T-sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies.
Yun-tao Guan - One of the best experts on this subject based on the ideXlab platform.
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effect of biofilm on cast Iron pipe corrosion in drinking water distribution system corrosion scales characterization and microbial community structure investigation
Corrosion Science, 2008Co-Authors: Fei Teng, Yun-tao GuanAbstract:Effect of biofilm on corrosion scales of cast Iron pipe was studied with the biofilm community structure investigated by PCR-DGGE to give an explanation to MIC from the viewpoint of microbial phase. Corrosion scales were identified with XRD and XPS. It was demonstrated that biofilm can greatly affect element composition and crystalline phase of corrosion scales. Biofilm can accelerate corrosion in 7 d, but inhibit corrosion after 7 d, which was due to Iron Bacteria and Iron reducing Bacteria (IRB), respectively. DGGE fingerprinting gave a well explanation to this transition, which might be contributed to the change of biofilm microbial diversity.
Terttu Vartiainen - One of the best experts on this subject based on the ideXlab platform.
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removal of soft deposits from the distribution system improves the drinking water quality
Water Research, 2004Co-Authors: Markku J Lehtola, Tarja Nissinen, Ilkka T Miettinen, Pertti J Martikainen, Terttu VartiainenAbstract:Deterioration in drinking water quality in distribution networks represents a problem in drinking water distribution. These can be an increase in microbial numbers, an elevated concentration of Iron or increased turbidity, all of which affect taste, odor and color in the drinking water. We studied if pipe cleaning would improve the drinking water quality in pipelines. Cleaning was arranged by flushing the pipes with compressed air and water. The numbers of Bacteria and the concentrations of Iron and turbidity in drinking water were highest at 9 p.m., when the water consumption was highest. Soft deposits inside the pipeline were occasionally released to bulk water, increasing the concentrations of Iron, Bacteria, microbially available organic carbon and phosphorus in drinking water. The cleaning of the pipeline decreased the diurnal variation in drinking water quality. With respect to Iron, only short-term positive effects were obtained. However, removing of the nutrient-rich soft deposits did decrease the microbial growth in the distribution system during summer when there were favorable warm temperatures for microbial growth. No Norwalk-like viruses or coliform Bacteria were detected in the soft deposits, in contrast to the high numbers of heterotrophic Bacteria.
Bertram Schmidt - One of the best experts on this subject based on the ideXlab platform.
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Isolation of Sphaerotilus-Leptothrix strains from Iron Bacteria communities in Tierra del Fuego wetlands.
FEMS microbiology ecology, 2014Co-Authors: Bertram Schmidt, Leandro Arturo Sanchez, Till Fretschner, Gastón Kreps, Marcela Alejandra Ferrero, Faustino Siñeriz, Ulrich SzewzykAbstract:Sheath-forming Iron- and manganese-depositing Bacteria belonging to the Sphaerotilus–Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced Iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG Bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG Bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and Iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1T-sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies.
Marco Stampanoni - One of the best experts on this subject based on the ideXlab platform.
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fossilized Iron Bacteria reveal a pathway to the biological origin of banded Iron formation
Nature Communications, 2013Co-Authors: Magnus Ivarsson, Stephanos P. Kilias, Veneta Belivanova, Marco Stampanoni, Danielle Fortin, Stefan Bengtson, Curt Broman, Federica MaroneAbstract:Debates on the formation of banded Iron formations in ancient ferruginous oceans are dominated by a dichotomy between abiotic and biotic Iron cycling. This is fuelled by difficulties in unravelling the exact processes involved in their formation. Here we provide fossil envIronmental evidence for anoxygenic photoferrotrophic deposition of analogue banded Iron rocks in shallow marine waters associated with an Early Quaternary hydrothermal vent field on Milos Island, Greece. Trace metal, major and rare earth elemental compositions suggest that the deposited rocks closely resemble banded Iron formations of Precambrian origin. Well-preserved microbial fossils in combination with chemical data imply that band formation was linked to periodic massive encrustation of anoxygenic phototrophic biofilms by Iron oxyhydroxide alternating with abiotic silica precipitation. The data implicate cyclic anoxygenic photoferrotrophy and their fossilization mechanisms in the construction of microskeletal fabrics that result in the formation of characteristic banded Iron formation bands of varying silica and Iron oxide ratios.