Simultaneous enumeration of denitrifying and nitrate reducing bacteria in soil by a microtiter most-probable-number (MPN) procedure

1981 ◽  
Vol 13 (5) ◽  
pp. 385-388 ◽  
Author(s):  
T.E. Staley ◽  
J.B. Griffin
Keyword(s):  
Most Probable Number ◽  
Probable Number ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

scholarly journals Denitrifying bacteria in the limnetic zone of Lake Tota, Colombia

2021 ◽  
Vol 26 (1) ◽  
pp. 1-16
Author(s):  
Julian Esteban Másmela-Mendoza ◽  
Luz Marina Lizarazo Forero
Keyword(s):  
Rainbow Trout ◽  
Fish Farming ◽  
Sampling Period ◽  
Denitrifying Bacteria ◽  
Most Probable Number ◽  
Nitrogen And Phosphorus ◽  
Probable Number ◽  
Physicochemical Factors ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

The objective of study was to isolate and determine the identity of denitrifying bacteria from limnetic areas of Lake Tota (Colombian Andes) with and without rainbow trout production activities. We examined the relationships between the lake’s physicochemical factors (oxygen, nitrogen, and phosphorus content) and two bacterial communities (denitrifying bacteria and coliforms). Water samples were taken 20m below the surface from July to September at five limnetic zones; two of which were close to rainbow trout farming areas. In each zone, the concentrations of oxygen, nitrogen, and phosphorus were measured. To identify and quantify the abundance of bacteria, the most probable number (MPN) technique was used, employing minimal medium for denitrifying bacteria and medium for nitrate reducing bacteria (NRB). A greater number of denitrifying bacteria were found in the fish farming zones, identifying bacteria of the genera Bacillus, Pseudomonas, Nocardia, and Streptomyces. The number of nitrate-reducing bacteria revealed statistically significant differences throughout the sampling period, increasing from July to September and was related to a decrease in precipitation. The density of NRB and total phosphorus were directly correlated. High bacterial densities of denitrifyingbacteria and coliforms are indicative of changes from oligotrophic to eutrophic states in the studied limnetic areas.

Applying a most probable number method for enumerating planktonic, dissimilatory, ammonium-producing, nitrate-reducing bacteria in oil field waters

2005 ◽  
Vol 51 (8) ◽  
pp. 725-729 ◽  
Author(s):  
Ruth E Eckford ◽  
Phillip M Fedorak
Keyword(s):  
Hydrogen Sulfide ◽  
Water Samples ◽  
Oil Field ◽  
Most Probable Number ◽  
Minor Role ◽  
Probable Number ◽  
A Minor ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Oil Field Water

A most probable number (MPN) method was used to enumerate dissimilatory ammonium-producing, nitrate-reducing bacteria (DAP-NRB) in oil field waters and to determine whether they were stimulated by nitrate addition used to control hydrogen sulfide production. An ammonium production medium with 5 carbon and energy sources (acetate, glucose, glycerol, pyruvate, and succinate) and nitrate was used in a 3-tube MPN procedure to enumerate DAP-NRB. These bacteria were detected in 12 of 18 oil field water samples, but they were seldom detected in wellhead samples. Three oil field water samples were amended with nitrate in serum bottles and the numbers of different NRB were determined over a 38-day incubation time. This amendment stimulated increases in the numbers of heterotrophic NRB and autotrophic nitrate-reducing, sulfide-oxidizing bacteria, but DAP-NRB remained a minor portion of these communities. Overall, DAP-NRB were present in many of the oil field waters that were examined but their numbers were low. It appears that DAP-NRB would play a minor role in the consumption of nitrate injected into oil field waters for the control of hydrogen sulfide production.Key words: heterotroph, nitrate-reducing bacteria, dissimilatory nitrate reduction, ammonium, petroleum.

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 Evidence for Microbial Fe(III) Reduction in Anoxic, Mining-Impacted Lake Sediments (Lake Coeur d'Alene, Idaho)

2000 ◽  
Vol 66 (1) ◽  
pp. 154-162 ◽  
Author(s):  
David E. Cummings ◽  
Anthony W. March ◽  
Benjamin Bostick ◽  
Stefan Spring ◽  
Frank Caccavo ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Dry Weight ◽  
Most Probable Number ◽  
Probable Number ◽  
Coeur D'alene ◽  
Reduction Of Iron ◽  
Study Support ◽  
Reducing Bacteria ◽  
Microbiological Data

ABSTRACT Mining-impacted sediments of Lake Coeur d'Alene, Idaho, contain more than 10% metals on a dry weight basis, approximately 80% of which is iron. Since iron (hydr)oxides adsorb toxic, ore-associated elements, such as arsenic, iron (hydr)oxide reduction may in part control the mobility and bioavailability of these elements. Geochemical and microbiological data were collected to examine the ecological role of dissimilatory Fe(III)-reducing bacteria in this habitat. The concentration of mild-acid-extractable Fe(II) increased with sediment depth up to 50 g kg−1, suggesting that iron reduction has occurred recently. The maximum concentrations of dissolved Fe(II) in interstitial water (41 mg liter−1) occurred 10 to 15 cm beneath the sediment-water interface, suggesting that sulfidogenesis may not be the predominant terminal electron-accepting process in this environment and that dissolved Fe(II) arises from biological reductive dissolution of iron (hydr)oxides. The concentration of sedimentary magnetite (Fe3O4), a common product of bacterial Fe(III) hydroxide reduction, was as much as 15.5 g kg−1. Most-probable-number enrichment cultures revealed that the mean density of Fe(III)-reducing bacteria was 8.3 × 105 cells g (dry weight) of sediment−1. Two new strains of dissimilatory Fe(III)-reducing bacteria were isolated from surface sediments. Collectively, the results of this study support the hypothesis that dissimilatory reduction of iron has been and continues to be an important biogeochemical process in the environment examined.

scholarly journals Enumeration and Detection of Anaerobic Ferrous Iron-Oxidizing, Nitrate-Reducing Bacteria from Diverse European Sediments

1998 ◽  
Vol 64 (12) ◽  
pp. 4846-4856 ◽  
Author(s):  
Kristina L. Straub ◽  
Berit E. E. Buchholz-Cleven
Keyword(s):  
In Situ Hybridization ◽  
Ferrous Iron ◽  
Anoxygenic Phototrophic Bacteria ◽  
Microbial Oxidation ◽  
Probable Number ◽  
Sediment Samples ◽  
Microbiological Methods ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

ABSTRACT Anaerobic, nitrate-dependent microbial oxidation of ferrous iron was recently recognized as a new type of metabolism. In order to study the occurrence of three novel groups of ferrous iron-oxidizing, nitrate-reducing bacteria (represented by strains BrG1, BrG2, and BrG3), 16S rRNA-targeted oligonucleotide probes were developed. In pure-culture experiments, these probes were shown to be suitable for fluorescent in situ hybridization, as well as for hybridization analysis of denaturing gradient gel electrophoresis (DGGE) patterns. However, neither enumeration by in situ hybridization nor detection by the DGGE-hybridization approach was feasible with sediment samples. Therefore, the DGGE-hybridization approach was combined with microbiological methods. Freshwater sediment samples from different European locations were used for enrichment cultures and most-probable-number (MPN) determinations. Bacteria with the ability to oxidize ferrous iron under nitrate-reducing conditions were detected in all of the sediment samples investigated. At least one of the previously described types of bacteria was detected in each enrichment culture. MPN studies showed that sediments contained from 1 × 105 to 5 × 108 ferrous iron-oxidizing, nitrate-reducing bacteria per g (dry weight) of sediment, which accounted for at most 0.8% of the nitrate-reducing bacteria growing with acetate. Type BrG1, BrG2, and BrG3 bacteria accounted for an even smaller fraction (0.2% or less) of the ferrous iron-oxidizing, nitrate-reducing community. The DGGE patterns of MPN cultures suggested that more organisms than those isolated thus far are able to oxidize ferrous iron with nitrate. A comparison showed that among the anoxygenic phototrophic bacteria, organisms that have the ability to oxidize ferrous iron also account for only a minor fraction of the population.

scholarly journals Rapid and Simple Method for the Most-Probable-Number Estimation of Arsenic-Reducing Bacteria

2001 ◽  
Vol 67 (7) ◽  
pp. 3168-3173 ◽  
Author(s):  
Linping Kuai ◽  
Arjun A. Nair ◽  
Martin F. Polz
Keyword(s):  
Dry Weight ◽  
Environmental Water ◽  
Microtiter Plate ◽  
Most Probable Number ◽  
Precipitation Reaction ◽  
Simple Method ◽  
Probable Number ◽  
Cell Counts ◽  
Pure Cultures ◽  
Reducing Bacteria

ABSTRACT A rapid and simple most-probable-number (MPN) procedure for the enumeration of dissimilatory arsenic-reducing bacteria (DARB) is presented. The method is based on the specific detection of arsenite, the end product of anaerobic arsenate respiration, by a precipitation reaction with sulfide. After 4 weeks of incubation, the medium for the MPN method is acidified to pH 6 and sulfide is added to a final concentration of about 1 mM. The brightly yellow arsenic trisulfide precipitates immediately and can easily be scored at arsenite concentrations as low as 0.05 mM. Abiotic reduction of arsenate upon sulfide addition, which could yield false positives, apparently produces a soluble As-S intermediate, which does not precipitate until about 1 h after sulfide addition. Using the new MPN method, population estimates of pure cultures of DARB were similar to direct cell counts. MPNs of environmental water and sediment samples yielded DARB numbers between 101 and 105 cells per ml or gram (dry weight), respectively. Poisoned and sterilized controls showed that potential abiotic reductants in environmental samples did not interfere with the MPN estimates. A major advantage is that the assay can be easily scaled to a microtiter plate format, enabling analysis of large numbers of samples by use of multichannel pipettors. Overall, the MPN method provides a rapid and simple means for estimating population sizes of DARB, a diverse group of organisms for which no comprehensive molecular markers have been developed yet.

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.

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