Colony-Forming Unit Enumeration by a Plate-MPN Method

1983 ◽  
Vol 46 (10) ◽  
pp. 836-841 ◽  
Author(s):  
S-T. TAN ◽  
R. B. MAXCY ◽  
W. W. STROUP
Keyword(s):  
Standard Technique ◽  
Most Probable Number ◽  
Plate Method ◽  
Probable Number ◽  
Microbial Counts ◽  
Colony Forming Unit ◽  
Pure Cultures ◽  
Petri Plate ◽  
Mpn Test ◽  
Surface Plate

Concepts of the standard surface plate method and the most probable number method (MPN) were combined to provide a new enumeration technique (plate-MPN). Three discrete 0.01-ml samples of an appropriate decimal dilution were inoculated onto each quadrant of a pre-dried petri plate. The discrete spots from the inoculum were then observed for growth after incubation. Results were interpreted analogous to a 3-tube MPN test using presently available tables. Application of the test to pure cultures and mixed flora provided no evidence to indicate the plate-MPN technique to be any less accurate than the standard technique for microbial counts. The plate-MPN technique was less precise than the standard technique. However, the plate-MPN technique has many advantages over traditional methods.

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.

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 Kualitas Air Sumur Gali Kelurahan Lubuk Buaya Kecamatan Koto Tangah Kota Padang Berdasarkan Indeks Most Probable Number (MPN)

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Randa Novalino ◽  
Netti Suharti ◽  
Arni Amir
Keyword(s):  
Water Quality ◽  
Health Department ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Well Water ◽  
Health Minister ◽  
Probable Number ◽  
Sources Of Pollution ◽  
Dug Well ◽  
Mpn Test

AbstrakDiare merupakan salah satu penyakit yang ditularkan melalui air terkontaminasi oleh agen penyebab seperti bakteri Coliform.  Menurut data Dinas Kesehatan Kota (DKK) Padang pada tahun 2011, kejadian diare di Kelurahan Lubuk Buaya Kecamatan Koto Tangah, Kota Padang merupakan kasus tertinggi di Kota Padang. Tujuan penelitian ini adalah menentukan kualitas air sumur gali di Kelurahan Lubuk Buaya berdasarkan Indeks Most Probable Number (MPN) menurut Peraturan Menteri Kesehatan Republik Indonesia (Permenkes RI) No. 416 tahun 1990. Sampel penelitian ini adalah  air sumur gali yang digunakan di beberapa Rukun Tetangga (RT), yang diambil secara acak dari beberapa Rukun Warga (RW) yang telah dipilih sebelumnya, sehingga didapatkan 15 sampel. Penelitian ini dilaksanakan dalam 2 tahap yaitu pengambilan sampel air sumur gali sekaligus observasi faktor yang mempengaruhi kualitas air dan pemeriksaan mikrobiologi dengan metode Most Probable Number (MPN) Test. Tes ini terdiri dari tes presumtif dan tes konfirmatif yang disesuaikan dengan Permenkes RI. Hasil penelitian ialah 73,33% dari jumlah sumur yang diperiksa tidak memenuhi standar Permenkes R.I. karena mengandung Coliform > 50 pada setiap 100 ml air. Hanya 26,6% sumur yang memenuhi standar yang telah ditetapkan. Beberapa faktor yang dapat mempengaruhi yaitu lokasi sumber pencemaran, dinding parapet, drainase, tutup sumur dan sarana pengambilan air.Kata kunci: kualitas air sumur gali, MPN, coliform AbstractDiarrhea is one of the diseases that  transmitted through contaminated water by causative agent, one of which is coliform bacteria. According to data from City Health Department Padang in 2011, the incidence of diarrhea in Kelurahan Lubuk Buaya Kecamatan Koto Tangah – Padang is the highest case in the city of Padang. The objective of this study was to determine the water quality of wells dug in Kelurahan Lubuk Buaya by Most Probable Number Index (MPN) according regulation of Indonesian health minister. The 15 samples was water of dug well  in some of the RT households from several neighborhoods that was selected. The research was conducted in two stages, dug well water samples as well as observation of the factors that affect water quality and microbiological examination of the Most Probable Number method (MPN) Test. This test consists of presumptive tests and confirmative tests that were tailored to regulation of Indonesian health minister.  The result were 73.33% of the wells tested did not meet the standards of Indonesian health minister regulation, because it contains >50 coliform in every 100 ml of water. Only 26.6% of the wells were inspected to meet the standards set. Several factors can affect the location of sources of pollution, parapet walls, drainage or sewer water, cover the wells, and water collection facilities.Keywords: dug well water quality, MPN, coliform

scholarly journals Improved soil and tomato quality by some biofertilizer products

2018 ◽  
pp. 93-105
Author(s):  
Borbála Bíró ◽  
Anita Dudás ◽  
Heléna Wass-Matics ◽  
Tamás Kocsis ◽  
Sándor Pabar ◽  
...  
Keyword(s):  
Fruit Quality ◽  
Soluble Sugars ◽  
Quality Parameters ◽  
Soluble Solids ◽  
Most Probable Number ◽  
Test Plant ◽  
P Availability ◽  
Tomato Fruits ◽  
Probable Number ◽  
Microbial Counts

The use of microbial inoculums is a part of sustainable agricultural practices. Among various bioeffectors, the phosphorus-mobilizing bacteria are frequently used. The objective of this study is to investigate the effect of some industrial biofertilizer inoculums, of containing P-mobilizing bacteria on the quantity and some quality parameters of tomato fruits. Spore-forming industrial Bacillus amyloliquefaciens FZB42 (Rhizovital) as single inoculums and combinations with other Bacillus strains (Biorex) were applied on Solanum lycopersicon Mill. var. Mobil test plant. Soil microbial counts, phosphorus availability, yield and fruit quality, such as total soluble solids (TSS) content and sugars (glucose, fructose) were assessed. The results found that single industrial inoculums of FZB42 product had positive effect on P-availability and fruit quality in the pots. Fruit quality parameters, TSS content, soluble sugars were significantly improved (p<0.05). Such better fruit taste was correlated significantly by the most probable number (MPN) microbial counts. Use of such bioeffector products is supported by the positive interrelation among measured soil characteristics and inside healthy quality parameters of tomato fruits.

Comparison of Legiolert and a Conventional Culture Method for Detection of Legionella pneumophila from Cooling Towers in Québec

2019 ◽  
Vol 102 (4) ◽  
pp. 1235-1240 ◽  
Author(s):  
Isabelle Barrette
Keyword(s):  
Legionella Pneumophila ◽  
Cooling Tower ◽  
Test Procedure ◽  
Agar Plate ◽  
Culture Method ◽  
Most Probable Number ◽  
Cooling Towers ◽  
Plate Method ◽  
Probable Number ◽  
Compliance Testing

Abstract Background: Legionnaires’ disease is a potentially lethal pneumonia contracted through inhalation of aerosolized water contaminated with Legionella bacteria. Detection and control of L. pneumophila, the primary species responsible for the disease, is critical to public health. In Québec, cooling towers and evaporative condensers are required to follow a maintenance and testing program to ensure L. pneumophila concentrations remain at acceptable levels. Objective: This study compared a new culture method based on the most probable number approach, Legiolert®, with the formal culture method used at EnvironeX for regulatory compliance testing to quantify L. pneumophila from cooling tower waters in Québec. Methods: A split-sample analysis was performed in which 401 samples from cooling towers in Québec were tested with both methods. Results: Results with 74 positive samples showed that Legiolert provided a significant increase in sensitivity for L. pneumophila compared with the agar plate method. Cooling tower samples often contain non-Legionella flora that necessitate multiple treatment and plating conditions to prevent interference with the test. Legiolert showed little to no impact from non-Legionella organisms in this study. Conclusions: Overall, Legiolert showed several advantages over the agar plate method, including increased sensitivity, reduced interference, a simplified test procedure, and an easy-to-read positive signal.

Identifikasi Kualitas Air Sumur, Air dalam Kemasan, dan Air Sungai dengan Metode Most Probable Number

2021 ◽  
Vol 10 (1) ◽  
pp. 40-45
Author(s):  
Ni Putu Trisna Ayundita
Keyword(s):  
Escherichia Coli ◽  
Most Probable Number ◽  
Probable Number ◽  
Mpn Test

Air memiliki peranan yang sangat besar salah satunya untuk kebutuhan biologisnya, yaitu bertahan hidup. Masalah utama yang dihadapi berkaitan dengan sumber daya air adalah kualitas air. Penentuan kualitas air secara mikrobiologi dilakukan dengan Most Probable Number (MPN) Test. Penelitian ini menggunakan 3 sampel yaitu air sumur, air dalam kemasan, dan air sungai. Air sumur mengandung Coliform dan Escherichia coli dengan jumlah yang sama yaitu 14 MPN/100 mL. Pada uji dugaan, air dalam kemasan menunjukkan hasil positif, namun saat diuji penetapan diperoleh hasil negatif. Sedangkan pada air sungai mengandung bakteri coliform lebih dari 1100 MPN/ 100 mL dan Escherichia coli sebanyak 11 MPN/ 100 mL.  Sampel air minum dalam kemasan layak dikonsumsi sedangkan untuk sampel air sumur dan air sungai tidak layak dikonsumsi karena mengandung Coliform dan Escherichia coli.

scholarly journals Bacteria and protozoa populations in groundwater in landfill area in São Carlos, SP

1999 ◽  
Vol 30 (3) ◽  
pp. 196-202 ◽  
Author(s):  
Roberta Fusconi ◽  
Mirna Januária Leal Godinho
Keyword(s):  
Heterotrophic Bacteria ◽  
Mean Value ◽  
Microbial Populations ◽  
Most Probable Number ◽  
Plate Method ◽  
Probable Number ◽  
Mean Values ◽  
The Mean ◽  
The Town ◽  
Microaerophilic Conditions

The microbial populations of groundwaters were analyzed in a region under the influence of a landfill (piezometer L12) in the town of São Carlos, São Paulo, Brazil, and in an area not influenced by the landfill (piezometer L5). Heterotrophic bacteria were counted by spread plate method and the number of protozoa was estimated by the most probable number method. There was a larger number of organisms in well L12, with a mean value of 15.76 x 104 CFU/ml for bacteria and 9.7 MPN/ml for protozoa, whereas the mean values for piezometer L5 were 2.88 x 104 CFU/ml for bacteria and 3.4 MPN/ml for protozoa. The greater abundance detected in piezometer L12 may be related to the influence of the leachate through the landfill on the microbial populations, also demonstrated by deoxygenation and by the high conductivity values (3530 µS/cm) compared to piezometer L5 (2.47 mg/L dissolved oxygen and 42 µS/cm conductivity). The most commonly detected protozoa were amoebae and flagellates. The density of flagellate protozoa determined under microaerophilic conditions was 10 times higher than that determined under aerobic conditions.

scholarly journals Evaluation of an MPN test for the rapid enumeration of Pseudomonas aeruginosa in hospital waters

2014 ◽  
Vol 13 (2) ◽  
pp. 427-436 ◽  
Author(s):  
David P. Sartory ◽  
Danièle Pauly ◽  
Nathalie Garrec ◽  
Lucia Bonadonna ◽  
Maurizio Semproni ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Filtration ◽  
Most Probable Number ◽  
Insufficient Data ◽  
Culture Methods ◽  
Probable Number ◽  
Rapid Enumeration ◽  
Relative Differences ◽  
Mpn Test ◽  
Atypical Strains

In this study, the performance of a new most probable number (MPN) test (Pseudalert®/Quanti-Tray®) for the enumeration of Pseudomonas aeruginosa from hospital waters was compared with both international and national membrane filtration-based culture methods for P. aeruginosa: ISO 16266:2006 and UK The Microbiology of Drinking Water – Part 8 (MoDW Part 8), which both use Pseudomonas CN agar. The comparison based on the calculation of mean relative differences between the two methods was conducted according to ISO 17994:2014. Using both routine hospital water samples (80 from six laboratories) and artificially contaminated samples (192 from five laboratories), paired counts from each sample and the enumeration method were analysed. For routine samples, there were insufficient data for a conclusive assessment, but the data do indicate at least equivalent performance of Pseudalert®/Quanti-Tray®. For the artificially contaminated samples, the data revealed higher counts of P. aeruginosa being recorded by Pseudalert®/Quanti-Tray®. The Pseudalert®/Quanti-Tray® method does not require confirmation testing for atypical strains of P. aeruginosa, saving up to 6 days of additional analysis, and has the added advantage of providing confirmed counts within 24–28 hours incubation compared to 40–48 hours or longer for the ISO 16266 and MoDW Part 8 methods.

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