scholarly journals Acetogenic and Sulfate-Reducing Bacteria Inhabiting the Rhizoplane and Deep Cortex Cells of the Sea Grass Halodule wrightii

1999 ◽  
Vol 65 (11) ◽  
pp. 5117-5123 ◽  
Author(s):  
Kirsten Küsel ◽  
Holly C. Pinkart ◽  
Harold L. Drake ◽  
Richard Devereux
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Epidermal Cells ◽  
Most Probable Number ◽  
Halodule Wrightii ◽  
Probable Number ◽  
Thin Sections ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Sea Grass ◽  
Reducing Bacteria

ABSTRACT Recent declines in sea grass distribution underscore the importance of understanding microbial community structure-function relationships in sea grass rhizospheres that might affect the viability of these plants. Phospholipid fatty acid analyses showed that sulfate-reducing bacteria and clostridia were enriched in sediments colonized by the sea grasses Halodule wrightii andThalassia testudinum compared to an adjacent unvegetated sediment. Most-probable-number analyses found that in contrast to butyrate-producing clostridia, acetogens and acetate-utilizing sulfate reducers were enriched by an order of magnitude in rhizosphere sediments. Although sea grass roots are oxygenated in the daytime, colorimetric root incubation studies demonstrated that acetogenic O-demethylation and sulfidogenic iron precipitation activities were tightly associated with washed, sediment-free H. wrightii roots. This suggests that the associated anaerobes are able to tolerate exposure to oxygen. To localize and quantify the anaerobic microbial colonization, root thin sections were hybridized with newly developed 33P-labeled probes that targeted (i) low-G+C-content gram-positive bacteria, (ii) cluster I species of clostridia, (iii) species of Acetobacterium, and (iv) species of Desulfovibrio. Microautoradiography revealed intercellular colonization of the roots by Acetobacteriumand Desulfovibrio species. Acetogenic bacteria occurred mostly in the rhizoplane and outermost cortex cell layers, and high numbers of sulfate reducers were detected on all epidermal cells and inward, colonizing some 60% of the deepest cortex cells. Approximately 30% of epidermal cells were colonized by bacteria that hybridized with an archaeal probe, strongly suggesting the presence of methanogens. Obligate anaerobes within the roots might contribute to the vitality of sea grasses and other aquatic plants and to the biogeochemistry of the surrounding sediment.

scholarly journals Community Size and Metabolic Rates of Psychrophilic Sulfate-Reducing Bacteria in Arctic Marine Sediments

1999 ◽  
Vol 65 (9) ◽  
pp. 4230-4233 ◽  
Author(s):  
Christian Knoblauch ◽  
Bo Barker Jørgensen ◽  
Jens Harder
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Physiological Adaptation ◽  
Most Probable Number ◽  
Metabolic Rates ◽  
Community Size ◽  
Probable Number ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Sulfate Reduction Rates ◽  
Reducing Bacteria

ABSTRACT The numbers of sulfate reducers in two Arctic sediments with in situ temperatures of 2.6 and −1.7°C were determined. Most-probable-number counts were higher at 10°C than at 20°C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than their mesophilic counterparts at similarly low temperatures.

Enumeration of selected bacterial populations in a high mountain watershed

1974 ◽  
Vol 20 (11) ◽  
pp. 1487-1492 ◽  
Author(s):  
Q. D. Skinner ◽  
J. C. Adams ◽  
P. A. Rechard ◽  
A. A. Beetle
Keyword(s):  
Sampling Site ◽  
Sulfate Reducing Bacteria ◽  
Most Probable Number ◽  
High Mountain ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Mountain Watershed ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Stream Systems

Nitrate-reducing bacteria, sulfate-reducing bacteria, fluorescent bacteria, and the total viable count were enumerated in three stream systems within a high mountain watershed over a period of two winters and two summers from 1970 to 1972. Spread plate and most probable number procedures showed that the number of fluorescent bacteria, sulfate-reducing bacteria, nitrate-reducing bacteria, and the total count were generally constant throughout the year at the lowest sampling site on the stream systems. However, in some cases and for short periods of time, the numbers of these bacteria appeared to be influenced by recreational use of the land and stream flow. For example, denitrifying bacteria increased in number during the winter recreational period and gave the lowest counts in July.

Improved Most-Probable-Number Method To Detect Sulfate-Reducing Bacteria with Natural Media and a Radiotracer

1998 ◽  
Vol 64 (5) ◽  
pp. 1700-1707 ◽  
Author(s):  
Flemming Vester ◽  
Kjeld Ingvorsen
Keyword(s):  
Sulfate Reduction ◽  
Environmental Samples ◽  
Sulfate Reducing Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Sulfate Reduction Rates ◽  
Synthetic Media ◽  
Reducing Bacteria ◽  
Natural Media

ABSTRACT A greatly improved most-probable-number (MPN) method for selective enumeration of sulfate-reducing bacteria (SRB) is described. The method is based on the use of natural media and radiolabeled sulfate (35SO4 2−). The natural media used consisted of anaerobically prepared sterilized sludge or sediment slurries obtained from sampling sites. The densities of SRB in sediment samples from Kysing Fjord (Denmark) and activated sludge were determined by using a normal MPN (N-MPN) method with synthetic cultivation media and a tracer MPN (T-MPN) method with natural media. The T-MPN method with natural media always yielded significantly higher (100- to 1,000-fold-higher) MPN values than the N-MPN method with synthetic media. The recovery of SRB from environmental samples was investigated by simultaneously measuring sulfate reduction rates (by a35S-radiotracer method) and bacterial counts by using the T-MPN and N-MPN methods, respectively. When bacterial numbers estimated by the T-MPN method with natural media were used, specific sulfate reduction rates (qSO4 2−) of 10−14to 10−13 mol of SO4 2−cell−1 day−1 were calculated, which is within the range of qSO4 2− values previously reported for pure cultures of SRB (10−15 to 10−14 mol of SO4 2− cell−1day−1). qSO4 2− values calculated from N-MPN values obtained with synthetic media were several orders of magnitude higher (2 � 10−10 to 7 � 10−10 mol of SO4 2−cell−1 day−1), showing that viable counts of SRB were seriously underestimated when standard enumeration media were used. Our results demonstrate that the use of natural media results in significant improvements in estimates of the true numbers of SRB in environmental samples.

scholarly journals Concentration of sheep manure bacteria in the immobilization of arsenic from groundwater using zero-valent

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Wahyu Wilopo ◽  
Keiko Sasaki ◽  
Tsuyoshi Hirajim
Keyword(s):  
Arsenic Concentration ◽  
Anaerobic Bacteria ◽  
Sulfate Reducing Bacteria ◽  
Permeable Reactive Barrier ◽  
Most Probable Number ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Sheep Manure ◽  
Population Size Estimates ◽  
Reducing Bacteria

Permeable reactive barrier column tests were performed to investigate whether anaerobic bacteria in sheep manure could help remove As from groundwater. One column served as a control and was packed with zero-valent iron (ZVI), compost leaf, wood chips, glass beads, and gravel, after which it was sterilized. The other (‘inoculated column’) was packed with the same ingredients, with the addition of sheep manure as a source of anaerobic bacteria. Simulated As-contaminated groundwater was prepared based on groundwater samples from Sumbawa Island, Indonesia, but with the arsenic concentration adjusted to 50 mg/L. The inoculated column was found to remove As more effectively from the simulated groundwater than the sterilized one. A gradual decrease in sulfate concentration was observed in the inoculated column at the rate of 0.26 mmol of sulfate/L/day, suggesting that there was sulfate-reducing activity in the microbial population. In addition, the sulfur isotope ratio showed -4.3 (‰) and 0.2 (‰) in influent and effluent, respectively, indicating that sulfate-reducing bacteria (SRB) consumed δ32S preferentially. Using population size estimates from the most probable number (MPN) method, the population of SRB was found to increase with distance traveled in the column. Profiling the community composition of the bacteria in different fractions of the inoculated column using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) on 16S rRNA sequences suggested that a majority of bacteria were various Clostridium species and one species of Proteobacteria, Geobacter metallireducens GS-15. Some of them may contribute to the removal of arsenic.Keywords: Sheep manure, zero valence iron, arsenic, immobilization, sulfate-reducing bacteria

scholarly journals Molecular Phylogenetic and Biogeochemical Studies of Sulfate-Reducing Bacteria in the Rhizosphere ofSpartina alterniflora

1999 ◽  
Vol 65 (5) ◽  
pp. 2209-2216 ◽  
Author(s):  
Mark E. Hines ◽  
Robert S. Evans ◽  
Barbara R. Sharak Genthner ◽  
Stephanie G. Willis ◽  
Stephanie Friedman ◽  
...  
Keyword(s):  
Plant Root ◽  
Sulfate Reducing Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Sediment Samples ◽  
Sulfate Reducing ◽  
Reduction Activity ◽  
Geochemical Parameters ◽  
Marsh Sediments ◽  
Reducing Bacteria

ABSTRACT The population composition and biogeochemistry of sulfate-reducing bacteria (SRB) in the rhizosphere of the marsh grass Spartina alterniflora was investigated over two growing seasons by molecular probing, enumerations of culturable SRB, and measurements of SO4 2− reduction rates and geochemical parameters. SO4 2− reduction was rapid in marsh sediments with rates up to 3.5 μmol ml−1day−1. Rates increased greatly when plant growth began in April and decreased again when plants flowered in late July. Results with nucleic acid probes revealed that SRB rRNA accounted for up to 43% of the rRNA from members of the domain Bacteria in marsh sediments, with the highest percentages occurring in bacteria physically associated with root surfaces. The relative abundance (RA) of SRB rRNA in whole-sediment samples compared to that ofBacteria rRNA did not vary greatly throughout the year, despite large temporal changes in SO4 2−reduction activity. However, the RA of root-associated SRB did increase from <10 to >30% when plants were actively growing. rRNA from members of the family Desulfobacteriaceae comprised the majority of the SRB rRNA at 3 to 34% of Bacteria rRNA, with Desulfobulbus spp. accounting for 1 to 16%. The RA ofDesulfovibrio rRNA generally comprised from <1 to 3% of the Bacteria rRNA. The highestDesulfobacteriaceae RA in whole sediments was 26% and was found in the deepest sediment samples (6 to 8 cm). Culturable SRB abundance, determined by most-probable-number analyses, was high at >107 ml−1. Ethanol utilizers were most abundant, followed by acetate utilizers. The high numbers of culturable SRB and the high RA of SRB rRNA compared to that ofBacteria rRNA may be due to the release of SRB substrates in plant root exudates, creating a microbial food web that circumvents fermentation.

scholarly journals Two Marine Desulfotomaculum spp. of Different Origin are Capable of Utilizing Acetone and Higher Ketones

2021 ◽  
Author(s):  
Jasmin Frey ◽  
Sophie Kaßner ◽  
Bernhard Schink
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Thiamine Diphosphate ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Different Origin

AbstractDegradation of acetone and higher ketones has been described in detail for aerobic and nitrate-reducing bacteria. Among sulfate-reducing bacteria, degradation of acetone and other ketones is still an uncommon ability and has not been understood completely yet. In the present work, we show that Desulfotomaculum arcticum and Desulfotomaculum geothermicum are able to degrade acetone and butanone. Total proteomics of cell-free extracts of both organisms indicated an involvement of a thiamine diphosphate-dependent enzyme, a B12-dependent mutase, and a specific dehydrogenase during acetone degradation. Similar enzymes were recently described to be involved in acetone degradation by Desulfococcus biacutus. As there are so far only two described sulfate reducers able to degrade acetone, D. arcticum and D. geothermicum represent two further species with this capacity. All these bacteria appear to degrade acetone via the same set of enzymes and therefore via the same pathway.

Competition for H2 between sulfate reducers, methanogens and homoacetogens in a gas-lift reactor

2002 ◽  
Vol 45 (10) ◽  
pp. 75-80 ◽  
Author(s):  
J. Weijma ◽  
F. Gubbels ◽  
L.W. Hulshoff Pol ◽  
A.J.M. Stams ◽  
P. Lens ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Sulfate Reduction ◽  
Growth Kinetic ◽  
Settling Velocity ◽  
Sulfate Reducing Bacteria ◽  
Anaerobic Sludge ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Reducing Bacteria ◽  
Gas Lift

Reported values for growth kinetic parameters show an order in competitivity of heterotrophic sulfate reducing bacteria&gt;methanogens&gt;homoacetogens for the substrate hydrogen. This order suggests that methanogens can succesfully compete with consortia of heterotrophic SRB and homoacetogens when H2/CO2 is present as sole substrate. However, we found in experiments using gas-lift reactors inoculated with anaerobic sludge and fed with H2/CO2 and sulfate, that heterotrophic sulfate reduction rapidly and completely outcompeted methanogenesis, whereas a low amount of acetate was formed. Thus, in disagreement with the above competitivity order, hydrogen is more readily consumed by homoacetogenesis than by methanogenesis, indicating that the competition is not kinetically determined. The superior settling velocity of sulfidogenic-acetogenic sludge compared to that of methanogenic sludge suggests that the former sludge is better retained, which can explain the predominance of sulfate reduction/homoacetogenesis over methanogenesis.

scholarly journals Molecular Characterization of Sulfate-Reducing Bacteria in the Guaymas Basin

2003 ◽  
Vol 69 (5) ◽  
pp. 2765-2772 ◽  
Author(s):  
Ashita Dhillon ◽  
Andreas Teske ◽  
Jesse Dillon ◽  
David A. Stahl ◽  
Mitchell L. Sogin
Keyword(s):  
16S Rrna ◽  
Gulf Of California ◽  
Sulfate Reducing Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Terrestrial Organic Matter ◽  
Guaymas Basin ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Reducing Bacteria

ABSTRACT The Guaymas Basin (Gulf of California) is a hydrothermal vent site where thermal alteration of deposited planktonic and terrestrial organic matter forms petroliferous material which supports diverse sulfate-reducing bacteria. We explored the phylogenetic and functional diversity of the sulfate-reducing bacteria by characterizing PCR-amplified dissimilatory sulfite reductase (dsrAB) and 16S rRNA genes from the upper 4 cm of the Guaymas sediment. The dsrAB sequences revealed that there was a major clade closely related to the acetate-oxidizing delta-proteobacterial genus Desulfobacter and a clade of novel, deeply branching dsr sequences related to environmental dsr sequences from marine sediments in Aarhus Bay and Kysing Fjord (Denmark). Other dsr clones were affiliated with gram-positive thermophilic sulfate reducers (genus Desulfotomaculum) and the delta-proteobacterial species Desulforhabdus amnigena and Thermodesulforhabdus norvegica. Phylogenetic analysis of 16S rRNAs from the same environmental samples resulted in identification of four clones affiliated with Desulfobacterium niacini, a member of the acetate-oxidizing, nutritionally versatile genus Desulfobacterium, and one clone related to Desulfobacula toluolica and Desulfotignum balticum. Other bacterial 16S rRNA bacterial phylotypes were represented by non-sulfate reducers and uncultured lineages with unknown physiology, like OP9, OP8, as well as a group with no clear affiliation. In summary, analyses of both 16S rRNA and dsrAB clone libraries resulted in identification of members of the Desulfobacteriales in the Guaymas sediments. In addition, the dsrAB sequencing approach revealed a novel group of sulfate-reducing prokaryotes that could not be identified by 16S rRNA sequencing.

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