scholarly journals Development of a Most-probable-number Method for Enumerating Denitrifying Bacteria by Using 96-Well Microtiter Plates and an Anaerobic Culture System

2003 ◽  
Vol 18 (4) ◽  
pp. 210-215 ◽  
Author(s):  
Satoshi Saitoh ◽  
Kazuhiro Iwasaki ◽  
Osami Yagi
Keyword(s):  
Culture System ◽  
Denitrifying Bacteria ◽  
Most Probable Number ◽  
Anaerobic Culture ◽  
Probable Number ◽  
Microtiter Plates

scholarly journals The Influence of Mineral Fertilizer Combined With a Nitrification Inhibitor on Microbial Populations and Activities in Calcareous Uzbekistanian Soil Under Cotton Cultivation

2001 ◽  
Vol 1 ◽  
pp. 108-113 ◽  
Author(s):  
Dilfuza Egamberdiyeva ◽  
Muhiddin Mamiev ◽  
Svetlana K. Poberejskaya
Keyword(s):  
Nitrification Inhibitor ◽  
Mineral Fertilizer ◽  
Denitrifying Bacteria ◽  
Nitrifying Bacteria ◽  
Most Probable Number ◽  
Nitrification Rate ◽  
Nitrification Inhibitors ◽  
Probable Number ◽  
Soil Microbial ◽  
Soil Microbial Population

Application of fertilizers combined with nitrification inhibitors affects soil microbial biomass and activity. The objective of this research was to determine the effects of fertilizer application combined with the nitrification inhibitor potassium oxalate (PO) on soil microbial population and activities in nitrogen-poor soil under cotton cultivation in Uzbekistan. Fertilizer treatments were N as urea, P as ammophos, and K as potassium chloride. The nitrification inhibitor PO was added to urea and ammophos at the rate of 2%. Three treatments—N200P140K60(T1), N200P140 POK60(T2), and N200P140 POK60(T3) mg kg-1soil—were applied for this study. The control (C) was without fertilizer and PO. The populations of oligotrophic bacteria, ammonifying bacteria, nitrifying bacteria, denitrifying bacteria, mineral assimilating bacteria, oligonitrophilic bacteria, and bacteria group Azotobacter were determined by the most probable number method. The treatments T2 and T3 increased the number of oligonitrophilic bacteria and utilization mineral forms of nitrogen on the background of reducing number of ammonifying bacteria. T2 and T3 also decreased the number of nitrifying bacteria, denitrifying bacteria, and net nitrification. In conclusion, our experiments showed that PO combined with mineral fertilizer is one of the most promising compounds for inhibiting nitrification rate, which was reflected in the increased availability and efficiency of fertilizer nitrogen to the cotton plants. PO combined with mineral fertilizer has no negative effects on nitrogen-fixing bacteria Azotobacter and oligo-nitrophilic 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.

Selective enumeration of aromatic and aliphatic hydrocarbon degrading bacteria by a most-probable-number procedure

1996 ◽  
Vol 42 (3) ◽  
pp. 252-258 ◽  
Author(s):  
Brian A. Wrenn ◽  
Albert D. Venosa
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Oxidation Products ◽  
Most Probable Number ◽  
Probable Number ◽  
Microtiter Plates ◽  
Degrading Bacteria ◽  
Polycyclic Aromatic ◽  
Pure Cultures ◽  
Plate Counts

A most-probable-number (MPN) procedure was developed to separately enumerate aliphatic and aromatic hydrocarbon degrading bacteria, because most of the currently available methods are unable to distinguish between these two groups. Separate 96-well microtiter plates are used to estimate the sizes of these two populations. The alkane-degrader MPN method uses hexadecane as the selective growth substrate and positive wells are detected by reduction of iodonitrotetrazolium violet, which is added after incubation for 2 weeks at 20 °C. Polycyclic aromatic hydrocarbon degraders are grown on a mixture of phenanthrene, anthracene, fluorene, and dibenzothiophene in a second plate. Positive wells turn yellow to greenish-brown from accumulation of the partial oxidation products of the aromatic substrates and they can be scored after a 3-week incubation period. These MPN procedures are accurate and selective. For pure cultures, heterotrophic plate counts on a nonselective medium and the appropriate MPN procedure provide similar estimates of the population density. Bacteria that cannot grow on the selective substrates do not produce false positive responses even when the inoculum density is very high. Thus, this method, which is simple enough for use in the field, provides reliable estimates for the density and composition of hydrocarbon-degrading microbial populations.Key words: most probable number, polycyclic aromatic hydrocarbon, alkane, hydrocarbon, bacteria.

Transformation of nitrogen and distribution of nitrogen-related bacteria in a polluted urban stream

2009 ◽  
Vol 60 (6) ◽  
pp. 1597-1605 ◽  
Author(s):  
Y. Jiao ◽  
W. B. Jin ◽  
Q. L. Zhao ◽  
G. D. Zhang ◽  
Y. Yan ◽  
...  
Keyword(s):  
Nitrate Concentration ◽  
Denitrifying Bacteria ◽  
Nitrogen Transformation ◽  
Nitrifying Bacteria ◽  
Urban Stream ◽  
Sediment Surface ◽  
Most Probable Number ◽  
Nitrogen Species ◽  
Probable Number ◽  
Selection Of

Most researchers focused on either nitrogen species or microbial community for polluted urban stream while ignoring the interaction between them and its effect on nitrogen transformation, which restricted the rational selection of an effective and feasible remediation technology. Taking Buji stream in Shenzhen (China) as target stream, the distribution of nitrogen-related bacteria was investigated by most probable number (MPN) besides analysis of nitrogen species etc. The nitrogen-related bacteria in sediment were 102 times richer than those in water. Owing to their faster growth, the MPN of ammonifying bacteria and denitrifying bacteria were 105 and 102 times higher than those of nitrifying bacteria, respectively. The ammonifying bacteria numbers were significantly related to BOD5 in water, while nitrifying bacteria in sediment correlated well with nitrate in water. Thus, nitrification occurred mainly in sediment surface and was limited by low proportion of nitrifying bacteria. The denitrifying bacteria in sediment had good relationship with BOD5 and nitrite and nitrate in water. Low DO and rich organic compounds were beneficial to denitrification but unfavourable to nitrification. Denitrification was restricted by low nitrite and nitrate concentration. These results could be served as a reference for implementing the remediation scheme of nitrogen polluted urban stream.

Influence of 1,2-Dichlorobenzene on Anaerobic Microorganisms in Wetland Soil

2013 ◽  
Vol 807-809 ◽  
pp. 676-679
Author(s):  
Hui Xing Liang ◽  
Ai Hui Chen ◽  
Cheng Ding ◽  
Zhao Xia Li
Keyword(s):  
Potential Effect ◽  
Denitrifying Bacteria ◽  
Most Probable Number ◽  
Wetland Soil ◽  
Probable Number ◽  
Anaerobic Microorganisms ◽  
Acetogenic Bacteria ◽  
Fermentative Bacteria ◽  
Experimental Process ◽  
Microbial Groups

The potential effect of 1,2-dichlorobenzene (1,2-DCB) on anaerobic microbial populations was investigated in a flooded wetland soil. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN) methods with anaerobic liquid enrichment media. In anaerobic microbe groups, the changes of bacterium group were not the same. 1,2-Dichlorobenzene had the maximum influence on microbial groups of wetland soil at the initial pollution. In dealing with 14-35 days, bacterium groups in each processing soil have different amplitude bouncing back. In the experimental process, bacteria which produces hydrogen and acetic acid is most sensitive to 1,2-Dichlorobenzene. Hydrolysis fermentation bacteria second, and denitrifying bacteria was the smallest.

scholarly journals Abundance of microorganisms and enzyme activity in the rapid-pool-benchland systems in natural Douliu River of China

2017 ◽  
Author(s):  
Zhen Hong Wang ◽  
Zhenhong Wang ◽  
Chen Chen ◽  
Qing Wu
Keyword(s):  
Enzyme Activity ◽  
Extracellular Enzymes ◽  
Denitrifying Bacteria ◽  
Middle Level ◽  
Ecosystem Functions ◽  
Most Probable Number ◽  
Microbial Abundance ◽  
Negative Effects ◽  
Probable Number ◽  
Urgent Task

Ecosystem functions of rivers have been greatly impaired due to the negative effects of human actions on river structures in different regions of the Earth during the last decades. It is an urgent task to understand the complete structures and ecosystem functions of a natural rive for restoration of the impaired river ecosystems. A natural river is composed of the repeatedly occurring rapid-pool-benchland system, i.e., a basic structural unit. We respectively selected three of the rapid-pool-benchland systems in the upper, middle and lower reaches of the Duliu River, a natural river in China as materials and tested the abundance of microorganisms in the sediments of these systems with plate counting method and a MPN (most-probable-number) method and the activity of enzymes with titration or colorimetric methods. Results indicated that the number of bacteria was far more than ammonifiers, actinomycetes, fungus and denitrifying bacteria in the sediments of all these rapid-pool-benchland systems. In each of the rapid-pool-benchland systems, all the microbial abundance in the sediments of the pools was always highest, and that of the rapids was lowest. In the upper reach, the microbial abundance was more than the middle and lower reaches. Catalase activity in the sediments of the benchlands was higher than the rapids and pools but phosphatase activity in the pools was higher than the rapids and benchlands. Phosphatas and urease activities were significantly correlated to the abundance of the bacteria, ammonifiers, actinomycetes, fungus and denitrifying bacteria in the sediments. The rapid-pool-benchland systems in a river obviously affect the microbial abundance and catalase and phosphatase activities related to biochemical functions in the sediments. However, the microbial abundance only indicated a middle-level correlations (r ranges from 0.434 to 0.836, p<0.05) with the activity of four extracellular enzymes. The study clarifies if the repeatedly occurring rapid-pool-benchland systems, a kind of habitat heterogeneity in a river have an effect on the microbial abundance and enzyme activity in the sediments, and further the relationships between the microbial abundance and enzyme activity.

scholarly journals Comparison of Methods for Quantification of Cytochrome cd1-Denitrifying Bacteria in Environmental Marine Samples

2000 ◽  
Vol 66 (4) ◽  
pp. 1564-1571 ◽  
Author(s):  
Valérie Michotey ◽  
Vincent Méjean ◽  
Patricia Bonin
Keyword(s):  
Water Samples ◽  
Denitrifying Bacteria ◽  
Molecular Techniques ◽  
Most Probable Number ◽  
Probable Number ◽  
Cultivation Method ◽  
Marine Samples ◽  
Functional Community ◽  
Specificity And Sensitivity ◽  
Primer Sets

ABSTRACT Two PCR primer sets were developed for the detection and quantification of cytochrome cd 1-denitrifying bacteria in environmental marine samples. The specificity and sensitivity of these primers were tested. Both primer sets were suitable for detection, but only one set, cd3F–cd4R, was suitable for the quantification and enumeration of the functional community using most-probable-number PCR and competitive PCR techniques. Quantification of cytochrome cd 1 denitrifiers taken from marine sediment and water samples was achieved using two different molecular techniques which target the nirS gene, and the results were compared to those obtained by using the classical cultivation method. Enumerations using both molecular techniques yielded similar results in seawater and sediment samples. However, both molecular techniques showed 1,000 or 10 times more cytochromecd 1 denitrifiers in the sediment or water samples, respectively, than were found by use of the conventional cultivation method for counting.

scholarly journals Abundance of microorganisms and enzyme activity in the rapid-pool-benchland systems in natural Douliu River of China

2017 ◽  
Author(s):  
Zhen Hong Wang ◽  
Zhenhong Wang ◽  
Chen Chen ◽  
Qing Wu
Keyword(s):  
Enzyme Activity ◽  
Extracellular Enzymes ◽  
Denitrifying Bacteria ◽  
Middle Level ◽  
Ecosystem Functions ◽  
Most Probable Number ◽  
Microbial Abundance ◽  
Negative Effects ◽  
Probable Number ◽  
Urgent Task

Ecosystem functions of rivers have been greatly impaired due to the negative effects of human actions on river structures in different regions of the Earth during the last decades. It is an urgent task to understand the complete structures and ecosystem functions of a natural rive for restoration of the impaired river ecosystems. A natural river is composed of the repeatedly occurring rapid-pool-benchland system, i.e., a basic structural unit. We respectively selected three of the rapid-pool-benchland systems in the upper, middle and lower reaches of the Duliu River, a natural river in China as materials and tested the abundance of microorganisms in the sediments of these systems with plate counting method and a MPN (most-probable-number) method and the activity of enzymes with titration or colorimetric methods. Results indicated that the number of bacteria was far more than ammonifiers, actinomycetes, fungus and denitrifying bacteria in the sediments of all these rapid-pool-benchland systems. In each of the rapid-pool-benchland systems, all the microbial abundance in the sediments of the pools was always highest, and that of the rapids was lowest. In the upper reach, the microbial abundance was more than the middle and lower reaches. Catalase activity in the sediments of the benchlands was higher than the rapids and pools but phosphatase activity in the pools was higher than the rapids and benchlands. Phosphatas and urease activities were significantly correlated to the abundance of the bacteria, ammonifiers, actinomycetes, fungus and denitrifying bacteria in the sediments. The rapid-pool-benchland systems in a river obviously affect the microbial abundance and catalase and phosphatase activities related to biochemical functions in the sediments. However, the microbial abundance only indicated a middle-level correlations (r ranges from 0.434 to 0.836, p<0.05) with the activity of four extracellular enzymes. The study clarifies if the repeatedly occurring rapid-pool-benchland systems, a kind of habitat heterogeneity in a river have an effect on the microbial abundance and enzyme activity in the sediments, and further the relationships between the microbial abundance and enzyme activity.

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