Enzyme-Based Most Probable Number Method for the Enumeration of Bifidobacterium in Dairy Products

2001 ◽  
Vol 64 (12) ◽  
pp. 2001-2006 ◽  
Author(s):  
RODRIGO BIBILONI ◽  
ANDREA GÓMEZ ZAVAGLIA ◽  
GRACIELA DE ANTONI
Keyword(s):  
Dairy Products ◽  
Accurate Determination ◽  
Most Probable Number ◽  
Commercial Products ◽  
Probable Number ◽  
Selective Media ◽  
Activity Determination ◽  
Pure Cultures

An enzyme-based assay in combination with the most probable number (MPN) technique was developed for the enumeration of bifidobacteria. The assay employs the detection of fructose-6-phosphate phosphoketolase (F6PPK) activity as an indicator of the presence of bifidobacteria. The method was validated against viable counts and optimized with respect to selective media in order to quantitatively assess bifidobacteria in dairy products and other probiotic preparations. Several commercial products and homemade fermented milks were analyzed. Counts of bifidobacteria ranged from 107 to 108 MPN/ml in commercial products and homemade fermented milks. Commercial starters provided by Argentinean industries had between 107 and 1011 MPN/ml. The results obtained in this study suggest that the combination of F6PPK activity determination and the MPN methodology allows an accurate determination of Bifidobacterium in pure cultures, dairy products, and other probiotic preparations.

Determination of the number of root nodule bacteria in the presence of other organisms

1962 ◽  
Vol 2 (4) ◽  
pp. 5 ◽  
Author(s):  
RA Date ◽  
JM Vincent
Keyword(s):  
Root Nodule ◽  
Plate Count ◽  
Most Probable Number ◽  
Dilution Method ◽  
Nodule Bacteria ◽  
Probable Number ◽  
Root Nodule Bacteria ◽  
Carrier Materials ◽  
Pure Cultures

Use of the plant-dilution method for the determination of the number of root-nodule bacteria in nonsterile carrier materials has been described for both small and large-seeded legume hosts. Calculation of the most probable number of rhizobia is described using values based on the appropriate tables of Fisher and Yates, and approximate factors of error for 95 per cent fiducial limits are stated. It was found that the plant-dilution method was likely to underestimate the number of rhizobia by a factor not greater than 2, when comparisons were made with pure cultures. However for non-sterile peat the tendency was for the plate count to give the lower estimate. This latter effect was no doubt due to the presence of other organisms and therefore the plant-dilution method is to be preferred in such cases.

scholarly journals TEMPO® TVC for the Enumeration of Aerobic Mesophilic Flora in Foods: Collaborative Study

2009 ◽  
Vol 92 (1) ◽  
pp. 165-174 ◽  
Author(s):  
Erin S Crowley ◽  
Patrick M Bird ◽  
Marianne K Torontali ◽  
James R Agin ◽  
David G Goins ◽  
...  
Keyword(s):  
Dairy Products ◽  
Collaborative Study ◽  
The United States ◽  
Automated System ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Standard Methods ◽  
Wide Range

Abstract The automated system for enumeration of total viable count (TVC) in foods, TEMPO® TVC, uses a dehydrated culture medium and an enumeration card containing 48 wells across 3 different dilutions for the automatic determination of the most probable number (MPN). The alternative method was compared in a multilaboratory collaborative study to AOAC Method 966.23 for determination of aerobic plate count for nondairy products and the Standard Methods for the Examination of Dairy Products (SMEDP) Standard Plate Count for dairy products. Five food types, raw ground beef, raw ground chicken, cooked whitefish fillets, bagged lettuce, and milk, were analyzed for TVC by 14 collaborating laboratories throughout the United States and Canada. Three lots of naturally contaminated food products representing a wide range of counts were tested for each of the 5 food types. The study demonstrated that the overall repeatability, reproducibility, and mean log counts of the TEMPO TVC method were statistically comparable to those of the 2 standard methods at the 5 level.

scholarly journals Determination of Amoebicidal Activities of Multipurpose Contact Lens Solutions by Using a Most Probable Number Enumeration Technique

2003 ◽  
Vol 41 (7) ◽  
pp. 2992-3000 ◽  
Author(s):  
T. K. Beattie ◽  
D. V. Seal ◽  
A. Tomlinson ◽  
A. K. McFadyen ◽  
A. M. Grimason
Keyword(s):  
Contact Lens ◽  
Most Probable Number ◽  
Probable Number ◽  
Contact Lens Solutions

scholarly journals Genus Alga pada Lahan Sawah Organik yang Ditanami Padi Lokal dan Inhibrida di Subak Jatiluwih, Tabanan

2019 ◽  
Vol 9 (2) ◽  
pp. 112
Author(s):  
SAWIDYA FITRIYANI ◽  
I WAYAN DANA ATMAJA ◽  
NI NENGAH SONIARI
Keyword(s):  
Soil Fertility ◽  
Research Method ◽  
Quantitative Method ◽  
Rice Fields ◽  
Most Probable Number ◽  
Water Sampling ◽  
Probable Number ◽  
Organic Rice ◽  
Soil And Water

Algae Genus in Organic Rice Fields Planted with Local and Inhibrida Rice in Subak Jatiluwih, Tabanan. The abundance of microalgae in rice fields, especially microalgae from Cyanophyta division that are capable of fixing nitrogen, is very important helping maintain soil fertility. The aim of this study was to find out the genus of algae in organic rice fields of Subak Jatiluwih, Tabanan. The research was conducted from September 2018 to April 2019. Sampling was done in Subak Jatiluwih. Algae breeding were carried out at Biology and Physics Laboratory, Faculty of Agriculture, Udayana University. This research method uses descriptive quantitative. The implementation of the research included the determination of location, soil and water sampling, identification of algae, and analysis of algae genera. Enrichment algae was carried out using the MPN method, results of the analysis of algae genus were found in 37 genera from 3 divisions i.e Chlorophyta, Cyanophyta and Chrysophyta. Descriptive quantitative method Most Probable Number (MPN) calculation conclude that there are not much different from the Local and Inhibrida rice fields. The maximum population algae of local rice fields is 1.100 cell g-1 and Inhibrida rice fields is >1.100 cell g-1 of land. The minimum population is 3,6 cell g-1 of land in local rice fields, and 9,2 cell g-1 of land in Inhibrida rice fields.

scholarly journals GENOMIC DETERMINATION OF THE MOST IMPORTANT FATHER LINES OF SLOVAK PINZGAU COWS

AGROFOR ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Veronika KUKUČKOVÁ ◽  
Nina MORAVČÍKOVÁ ◽  
Radovan KASARDA
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
The State ◽  
Most Probable Number ◽  
Pedigree Data ◽  
Probable Number ◽  
Expected Heterozygosity ◽  
High Level ◽  
The Bayesian Approach

The aim of this study was to assess genetic structure of Slovak Pinzgau populationbased on polymorphism at molecular markers using statistical methods. Femaleoffspring of 12 most frequently used bulls in Slovak Pinzgau breeding programmewere investigated. Pinzgau cattle were found to have a high level of diversity,supported by the number of alleles observed across loci (average 5.31, range 2-11)and by the high within-breed expected heterozygosity (average 0.66, range 0.64-0.73). The state of genetic diversity is satisfying and standard for local populations.Detection of 12 possible subpopulation structures provided us with detailedinformation of the genetic structure. The Bayesian approach was applied, detectingthree, as the most probable number of clusters. The similarity of eachsubpopulation using microsatellites was confirmed also by high-throughputmolecular data. The observed inbreeding (FROH=2.3%) was higher than thatexpected based on pedigree data (FPED=0.4%) due to the limited number ofavailable generations in pedigree data. One of the most important steps indevelopment of efficient autochthonous breed protection programs ischaracterization of genetic variability and assessment of the population structure.The chosen set of microsatellites confirmed the suitability in determination of thesubpopulations of Pinzgau cattle in Slovakia. The state of genetic diversity at moredetailed level was successfully performed using bovineSNP50 BeadChip.

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.

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.

scholarly journals Determination of the biodegradability of chitosan utilizing the most probable number technique

2020 ◽  
Vol 42 ◽  
pp. e52965
Author(s):  
Wender Cardoso Silva ◽  
Ilva de Fátima Souza ◽  
Vivian Machado Benassi ◽  
Juan Pedro Bretas Roa ◽  
Paulo Henrique Graziotti ◽  
...  
Keyword(s):  
Soil Microorganisms ◽  
Culture Medium ◽  
Culture Media ◽  
Soil Samples ◽  
Most Probable Number ◽  
Probable Number ◽  
Strong Indicator ◽  
Specific Culture ◽  
Chitosan Biopolymer

The present work aimed to evaluate the degradability of the chitosan polymer by soil microorganisms. This evaluation was accomplished using the Most Probable Number (MPN) method by plating in drops so that soil microorganisms capable of degrading the polymeric material could be quantified. Soil samples diluted in three specific culture media for each type of microorganism were plated – bacteria, fungi and actinobacteria – and they were maintained at 28°C for seven days to determine the growth rate of fungi and actinobacteria, and for 48 hours for the development of bacteria. Significant differences in the MPN of actinobacteria relative to the other groups analyzed were observed. Thus, the method used was effective for determining the degradability of the chitosan biopolymer when observing the development of microorganisms subjected to the replacement of the carbon source by the addition of 2% w v-1 of the chitosan biopolymer to the culture medium. The formation of clear regions around the microbial colonies was a strong indicator of biodegradation.

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