scholarly journals Composition and Function of Sulfate-Reducing Prokaryotes in Eutrophic and Pristine Areas of the Florida Everglades

2002 ◽  
Vol 68 (12) ◽  
pp. 6129-6137 ◽  
Author(s):  
Hector Castro ◽  
K. R. Reddy ◽  
Andrew Ogram
Keyword(s):  
Carbon Sources ◽  
Original System ◽  
Agricultural Runoff ◽  
Florida Everglades ◽  
Most Probable Number ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Limited Degree ◽  
Sulfate Reduction Rates ◽  
And Function

ABSTRACT As a result of agricultural activities in regions adjacent to the northern boundary of the Florida Everglades, a nutrient gradient developed that resulted in physicochemical and ecological changes from the original system. Sulfate input from agricultural runoff and groundwater is present in soils of the Northern Everglades, and sulfate-reducing prokaryotes (SRP) may play an important role in biogeochemical processes such as carbon cycling. The goal of this project was to utilize culture-based and non-culture-based approaches to study differences between the composition of assemblages of SRP in eutrophic and pristine areas of the Everglades. Sulfate reduction rates and most-probable-number enumerations revealed SRP populations and activities to be greater in eutrophic zones than in more pristine soils. In eutrophic regions, methanogenesis rates were higher, the addition of acetate stimulated methanogenesis, and SRP able to utilize acetate competed to a limited degree with acetoclastic methanogens. A surprising amount of diversity within clone libraries of PCR-amplified dissimilatory sulfite reductase (DSR) genes was observed, and the majority of DSR sequences were associated with gram-positive spore-forming Desulfotomaculum and uncultured microorganisms. Sequences associated with Desulfotomaculum fall into two categories: in the eutrophic regions, 94.7% of the sequences related to Desulfotomaculum were associated with those able to completely oxidize substrates, and in samples from pristine regions, all Desulfotomaculum-like sequences were related to incomplete oxidizers. This metabolic selection may be linked to the types of substrates that Desulfotomaculum spp. utilize; it may be that complete oxidizers are more versatile and likelier to proliferate in nutrient-rich zones of the Everglades. Desulfotomaculum incomplete oxidizers may outcompete complete oxidizers for substrates such as hydrogen in pristine zones where diverse carbon sources are less available.

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 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.

Influence of the origin of the inoculum on the anaerobic biodegradability test

2004 ◽  
Vol 49 (1) ◽  
pp. 53-59 ◽  
Author(s):  
I. Moreno-Andrade ◽  
G. Buitrón
Keyword(s):  
Most Probable Number ◽  
Microbial Composition ◽  
Probable Number ◽  
Methanogenic Activity ◽  
Sulfate Reducing ◽  
Anaerobic Biodegradability ◽  
Specific Methanogenic Activity ◽  
Solids Content ◽  
Different Sources ◽  
Selection Of

Five different sources of inocula were studied to determine its influence on biodegradability tests. Inocula were characterized determining granulometry, specific methanogenic activity, solids content, and volumetric sludge index. Also, the fermentative, aceticlastic, hydrogenophilic, OPHA, and sulfate-reducing groups were determined by the most probable number technique. Anaerobic biodegradability tests were conducted with two different substrates, one easy to degrade (glucose) and a toxic one (phenol). The best performance, in terms of percent of biodegradation and lag time, for both substrates, was obtained with the inoculum from a brewery industry UASB. The results can be explained in terms of the initial activity of the inoculum. The influence of the significant variations found in the specific methanogenic activity of the five inocula studied is discussed, in terms of the microbial composition of the samples. The results emphasized the importance of the selection of an appropriate source of inoculum in order to obtain reliable results.

A Method of Profiling Microbial Communities Based on a Most-Probable-Number Assay That Uses BIOLOG Plates and Multiple Sole Carbon Sources

1999 ◽  
Vol 65 (10) ◽  
pp. 4419-4424 ◽  
Author(s):  
Masashi Gamo ◽  
Tadashi Shoji
Keyword(s):  
Bacterial Communities ◽  
Carbon Sources ◽  
High Rate ◽  
Most Probable Number ◽  
Probable Number ◽  
New Approach ◽  
Mixing Ratios ◽  
Color Development ◽  
Assay Procedure ◽  
Pure Cultures

ABSTRACT A new approach to the community-level BIOLOG assay was proposed. This assay, which we call the BIOLOG-MPN assay, is a most-probable-number (MPN) assay that uses BIOLOG plates and multiple sole carbon sources, and the profiles obtained by this assay consist of MPNs estimated for the substrates in the BIOLOG plates. In order to demonstrate the performance of the BIOLOG-MPN assay, it was applied to pure cultures, model bacterial communities that contain two strains in different ratios, and microbial community samples. MPN estimation using BIOLOG plates worked well for the substrates on which utilizers can grow at a sufficiently high rate for color development under the conditions of the assay procedure. Furthermore, the results obtained using model communities showed that the MPNs obtained reflected the mixing ratios of pure cultures in the model communities. The profiles obtained using model communities and community samples were differentiated properly by statistical analyses. The results suggest that the BIOLOG-MPN assay is a promising procedure for obtaining a quantitative picture of the community structure.

scholarly journals Distribution and Physiological Characteristics of Hyperthermophiles in the Kubiki Oil Reservoir in Niigata, Japan

2000 ◽  
Vol 66 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Yoh Takahata ◽  
Miyuki Nishijima ◽  
Toshihiro Hoaki ◽  
Tadashi Maruyama
Keyword(s):  
Cell Density ◽  
Carbon Sources ◽  
Most Probable Number ◽  
Oil Reservoir ◽  
Formation Water ◽  
Probable Number ◽  
Initial Cell ◽  
Initial Cell Density ◽  
Inorganic Substances ◽  
Subterranean Environment

ABSTRACT The distribution of culturable hyperthermophiles was studied in relation to environmental conditions in the Kubiki oil reservoir in Japan, where the temperature was between 50 and 58°C. Dominant hyperthermophilic cocci and rods were isolated and shown to belong to the genera Thermococcus and Thermotoga, respectively, by 16S rDNA analyses. Using the most-probable-number method, we found that hyperthermophilic cocci were widely distributed in several unconnected fault blocks in the Kubiki oil reservoir. In 1996 to 1997, their populations in the production waters from oil wells were 9.2 × 103 to 4.6 × 104cells/ml, or 10 to 42% of total cocci. On the other hand, hyperthermophilic rods were found in only one fault block of the reservoir with populations less than 10 cells/ml. DominantThermococcus and Thermotoga spp. grew at reservoir temperatures and utilized amino acids and sugars, respectively, as sole carbon sources. While organic carbon was plentiful in the environment, these hyperthermophiles were unable to grow in the formation water due to lack of essential nutrients. Concentrations of some organic and inorganic substances differed among fault blocks, indicating that the movement of formation water between fault blocks was restricted. This finding suggests that the supply of nutrients via fluid current is limited in this subterranean environment and that the organisms are starved in the oil reservoir. Under starved conditions at 50°C, culturable cells of Thermococcus sp. remained around the initial cell density for about 200 days, while those of Thermotoga sp. decreased exponentially to 0.01% of the initial cell density after incubation for the same period. The difference in survivability between these two hyperthermophiles seems to reflect their populations in the fault blocks. These results indicate that hyperthermophilic cocci and rods adapt to the subterranean environment of the Kubiki oil reservoir by developing an ability to survive under starved conditions.

scholarly journals Microscale and Molecular Assessment of Impacts of Nickel, Nutrients, and Oxygen Level on Structure and Function of River Biofilm Communities

2004 ◽  
Vol 70 (7) ◽  
pp. 4326-4339 ◽  
Author(s):  
J. R. Lawrence ◽  
M. R. Chenier ◽  
R. Roy ◽  
D. Beaumier ◽  
N. Fortin ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Molecular Probes ◽  
Community Diversity ◽  
Most Probable Number ◽  
Probable Number ◽  
Negative Effect ◽  
Do Concentration ◽  
River Biofilm ◽  
Biofilm Development ◽  
And Function

ABSTRACT Studies were carried out to assess the influence of nutrients, dissolved oxygen (DO) concentration, and nickel (Ni) on river biofilm development, structure, function, and community composition. Biofilms were cultivated in rotating annular reactors with river water at a DO concentration of 0.5 or 7.5 mg liter−1, with or without a combination of carbon, nitrogen, and phosphorus (CNP) and with or without Ni at 0.5 mg liter−1. The effects of Ni were apparent in the elimination of cyanobacterial populations and reduced photosynthetic biomass in the biofilm. Application of lectin-binding analyses indicated changes in exopolymer abundance and a shift in the glycoconjugate makeup of the biofilms, as well as in the response to all treatments. Application of the fluorescent live-dead staining (BacLight Live-Dead staining kit; Molecular Probes, Eugene, Oreg.) indicated an increase in the ratio of live to dead cells under low-oxygen conditions. Nickel treatments had 50 to 75% fewer ‘live’ cells than their corresponding controls. Nickel at 0.5 mg liter−1 corresponding to the industrial release rate concentration for nickel resulted in reductions in carbon utilization spectra relative to control and CNP treatments without nickel. In these cases, the presence of nickel eliminated the positive influence of nutrients on the biofilm. Other culture-dependent analyses (plate counts and most probable number) revealed no significant treatment effect on the biofilm communities. In the presence of CNP and at both DO levels, Ni negatively affected denitrification but had no effect on hexadecane mineralization or sulfate reduction. Analysis of total community DNA indicated abundant eubacterial 16S ribosomal DNA (rDNA), whereas Archaea were not detected. Amplification of the alkB gene indicated a positive effect of CNP and a negative effect of Ni. The nirS gene was not detected in samples treated with Ni at 0.5 mg liter−1, indicating a negative effect on specific populations of bacteria, such as denitrifiers, resulting in a reduction in diversity. Denaturing gradient gel electrophoresis revealed that CNP had a beneficial impact on biofilm bacterial diversity at high DO concentrations, but none at low DO concentrations, and that the negative effect of Ni on diversity was similar at both DO concentrations. Notably, Ni resulted in the appearance of unique bands in 16S rDNA from Ni, DO, and CNP treatments. Sequencing results confirmed that the bands belonged to bacteria originating from freshwater and marine environments or from agricultural soils and industrial effluents. The observations indicate that significant interactions occur between Ni, oxygen, and nutrients and that Ni at 0.5 mg liter−1 may have significant impacts on river microbial community diversity and function.

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.

scholarly journals Microbial Communities in Contaminated Sediments, Associated with Bioremediation of Uranium to Submicromolar Levels

2008 ◽  
Vol 74 (12) ◽  
pp. 3718-3729 ◽  
Author(s):  
Erick Cardenas ◽  
Wei-Min Wu ◽  
Mary Beth Leigh ◽  
Jack Carley ◽  
Sue Carroll ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Contaminated Site ◽  
Most Probable Number ◽  
Biological Reduction ◽  
Probable Number ◽  
Oak Ridge ◽  
Sulfate Reducing ◽  
Treatment Zone ◽  
The U.S

ABSTRACT Microbial enumeration, 16S rRNA gene clone libraries, and chemical analysis were used to evaluate the in situ biological reduction and immobilization of uranium(VI) in a long-term experiment (more than 2 years) conducted at a highly uranium-contaminated site (up to 60 mg/liter and 800 mg/kg solids) of the U.S. Department of Energy in Oak Ridge, TN. Bioreduction was achieved by conditioning groundwater above ground and then stimulating growth of denitrifying, Fe(III)-reducing, and sulfate-reducing bacteria in situ through weekly injection of ethanol into the subsurface. After nearly 2 years of intermittent injection of ethanol, aqueous U levels fell below the U.S. Environmental Protection Agency maximum contaminant level for drinking water and groundwater (<30 μg/liter or 0.126 μM). Sediment microbial communities from the treatment zone were compared with those from a control well without biostimulation. Most-probable-number estimations indicated that microorganisms implicated in bioremediation accumulated in the sediments of the treatment zone but were either absent or in very low numbers in an untreated control area. Organisms belonging to genera known to include U(VI) reducers were detected, including Desulfovibrio, Geobacter, Anaeromyxobacter, Desulfosporosinus, and Acidovorax spp. The predominant sulfate-reducing bacterial species were Desulfovibrio spp., while the iron reducers were represented by Ferribacterium spp. and Geothrix spp. Diversity-based clustering revealed differences between treated and untreated zones and also within samples of the treated area. Spatial differences in community structure within the treatment zone were likely related to the hydraulic pathway and to electron donor metabolism during biostimulation.

The exploration of the effective methods to evaluate the stripping ability of bacteriacide to SRB biofilm

2016 ◽  
Vol 63 (6) ◽  
pp. 445-451
Author(s):  
Yanan Wu ◽  
Hongfang Liu ◽  
Bijuan Zheng ◽  
Shuang Qin ◽  
Lei Chen
Keyword(s):  
Design Methodology ◽  
Electrochemical Impedance ◽  
Three Dimensional ◽  
Most Probable Number ◽  
Probable Number ◽  
Content Type ◽  
Sulfate Reducing ◽  
Effective Evaluation ◽  
Eis Measurements ◽  
Reducing Bacteria

Purpose The purpose of this paper was to study some effective evaluation methods for the biocide performance on sulfate-reducing bacteria (SRB) biofilm. Design/methodology/approach The most probable number method, electrochemical impedance spectroscopy (EIS) measurements, scanning electron microscopy (SEM), three-dimensional (3D) photos and epifluorescent microscopy were used in this study. Findings The results showed that the minimum inhibitory concentrations and minimum bactericidal concentrations of them to sessile SRB were greatly more than planktonic SRB. The EIS of the two biocides indicated that the biofilm exposed to higher concentrations of biocide were much more compact and flat, which perfectly coincided with the SEM, 3D photos and the epifluorescent microscopies. Originality/value In this paper, it, thus, appears that these methods evaluating biocide performance on the SRB biofilm were really effective by comparing the performance of bis-quaternary ammonium salt (BAQS) and tetrakis hydroxymethyl phosphonium sulfate.

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