Search

Your search keyword '"Nougang M"' showing total 5 results
Start Over Author "Nougang M"
5 results on '"Nougang M"'

1. Assessment of in-situ abundance dynamics of enterobacteria and total heterotrophic aerobic bacteria in groundwater in the equatorial region of Central Africa

Author

Nola, M., Eheth, J. S., Nougang, M. E., Moungang, M.L., Noah Ewoti, O.V., Krier, F., Chihib, N.E., Servais, Pierre, Hornez, J.-P., and Njine, Thomas

Subjects
chemical, growth, THAB, Management, Monitoring, Policy and Law, inhibition rate, Applied Microbiology and Biotechnology, enterobacteria, THAB, growth rate, inhibition rate, groundwater, chemical, rate, inhibition, Environnement et pollution, groundwater, growth rate, Microbiologie et protistologie [bacteriol.virolog.mycolog.], Waste Management and Disposal, enterobacteria, Water Science and Technology
Abstract

The main purpose of this investigation was to assess, in situ, the hourly abundance dynamics of enterobacteria and total heterotrophic aerobic bacteria (THAB), over a daily period, in 3 wells in Yaounde region, Cameroon. Sampling was done weekly, for 4 months. Water samples were collected in sterile glass bottles and incubated in situ for 2 h, 4 h, 6 h, 8 h, 10 h and 12 h. Isolation and enumeration of enterobacteria and THAB were performed on MacConkey agar (Bio-Rad) and standard agar (Bio-Rad) media, respectively, using the plate count method. Using a linear regression model, ln(number of CFUs) was plotted against time. The slope of each regression line was considered as the apparent increase or decrease in cell number. Concentrations of THAB and enterobacteria varied from 9.90 to 14.19 and 4.09 to 9.59 ln units∙mℓ-1, respectively, in W1, from 9.90 to 14.25 and 3.00 to 5.39 ln units∙mℓ-1 in W2, and from 9.90 to 14.00 and 6.55 to 11.51 ln units∙mℓ-1 in W3. For the first 6-hour incubation period at all of the sampling points, the cell apparent growth rate (CAGR) varied from 0.023 to 0.262 h-1 for THAB and from 0.001 to 0.315 h-1 for enterobacteria; cell apparent inhibition rate (CAIR) varied from 0.015 to 0.615 h-1 for THAB and from 0.015 to 0.604 h-1 for enterobacteria. In the second 6-h incubation period, the CAGR varied from 0.010 to 0.822 h-1 for THAB and from 0.015 to 0.771 h-1 for enterobacteria; the CAIR varied from 0.015 to 0.260 h-1 for THAB and from 0.007 to 0.338 h-1 for enterobacteria. The values of physico-chemical parameters recorded before incubation displayed temporal and spatial variation over the sampling period. Bacterial abundance dynamics in some cases was significantly correlated to some of these abiotic factors. The abundance of the microorganisms decreased initially but later increased., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2012

2. Bacterial adhesion on the rock fragments immersed in wells in the equatorial region of Cameroon (Central Africa): a study on the potential effect of the day and night immersion period

Author

Moungang, M.L., Nola, M., Nougang, M. E., Noah Ewoti, O.V., Chihib, N.E., Krier, F., Servais, Pierre, Moungang, M.L., Nola, M., Nougang, M. E., Noah Ewoti, O.V., Chihib, N.E., Krier, F., and Servais, Pierre

Abstract

This study aims to evaluate the abundance of heterotrophic aerobe bacteria (HAB) adhered during the dayperiod and the night to fragments of granite, basalt and migmatite immersed in 2 well water points. Theincubation periods were 12h in day time, 12h at night and 24h (day and night). For the 2 wells the highestabundance of the HAB adhered on granite, basalt and migmatite varied respectively from 11.20 to 11.94, 11.49 to11.54 and from 12.16 to 13.68 (Log (CFU/cm2)) during the day period, respectively from10.92 to 12, 10.40 to11.37 and from 10.20 to 11.79 (Log (CFU/cm2)) during the night period, and respectively from 10.70 to 11.13,10.47 to 10.59, and from 10.56 to 11.17 (Log (CFU/cm2)) during the 24h incubation period. The abioticparameters considered and assessed at 6 am on each sampling day were pH, electrical conductivity, totalsuspended solids, color, turbidity and the water column thickness. The Principal Component Analysis (PCA)showed for each of rock-type, a relative variation with respect to incubation period of the percentage ofinformation contained in each principal axis. This could be due to the substantial influence of incubation periodand some meteorological parameters on hydrological properties of water as well as the bacterial and rockfragmentsurface., info:eu-repo/semantics/published

Published
2013

3. Involvement of cell shape and flagella in the bacterial retention during percolation of contaminated water through soil columns in tropical region

Author

Nola, M., Noah Ewoti, O.V., Nougang, M., Moungang, M.L., Chihib, N.E., Krier, F., Servais, Pierre, Hornez, J.-P., Nijne, T., Nola, M., Noah Ewoti, O.V., Nougang, M., Moungang, M.L., Chihib, N.E., Krier, F., Servais, Pierre, Hornez, J.-P., and Nijne, T.

Abstract

Microorganisms' retention in soil contributes to the natural purification of groundwater. Bacteria found in groundwater are generally of various shapes. The aim of this study was to assess the importance of cell shape and flagella in bacterial retention during polluted water percolation through two soil columns CA and CB, in the equatorial region in Central Africa. Percolation tests were carried out using different water loads samples which were contaminated by Escherichia coli (straight rods, peritrichous flagella), Vibrio parahaemolyticus (rods bacteria, polar flagella), and Staphylococcus saprophyticus (spherical, free-flagellum). It has been noted that showed that through soil column CA, the mean values of cells retention ratios (TR) varied with bacteria species considered, and from one applied water load sample to another. E. coli TR and that of S. saprophyticus were not significantly different (P> 0.05) for the two soil columns. V. parahaemolyticus TR significantly differed from that of E. coli and S. saprophyticus through soil column CA (P< 0.01) when the highest water load was applied, and through soil column CB (P< 0.05) for each of water load applied. A relative hierarchical arrangement of retained cells based on the TR showed that V. parahaemolyticus was less retained through the 2 soil columns. S. saprophyticus in most cases was more retained than others. The physical properties of the bacterial cell must be taken into consideration when evaluating the transfer of bacteriological pollutants towards groundwater., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2010

4. Involvement of cell shape and flagella in the bacterial retention during percolation of contaminated water through soil columns in tropical region.

Author

Nola M, Ewoti OV, Nougang M, Moungang ML, Chihib NE, Krier F, Servais P, Hornez JP, and Njine T

Subjects
Bacteria chemistry, Bacteria metabolism, Escherichia coli chemistry, Escherichia coli cytology, Escherichia coli metabolism, Flagella chemistry, Flagella metabolism, Soil Microbiology, Staphylococcus chemistry, Staphylococcus cytology, Staphylococcus metabolism, Vibrio chemistry, Vibrio cytology, Vibrio metabolism, Water Pollutants chemistry, Water Pollutants metabolism, Bacteria cytology, Water Pollutants analysis, Water Purification methods
Abstract

Microorganisms' retention in soil contributes to the natural purification of groundwater. Bacteria found in groundwater are generally of various shapes. The aim of this study was to assess the importance of cell shape and flagella in bacterial retention during polluted water percolation through two soil columns CA and CB, in the equatorial region in Central Africa. Percolation tests were carried out using different water loads samples which were contaminated by Escherichia coli (straight rods, peritrichous flagella), Vibrio parahaemolyticus (rods bacteria, polar flagella), and Staphylococcus saprophyticus (spherical, free-flagellum). It has been noted that showed that through soil column CA, the mean values of cells retention ratios (T(R)) varied with bacteria species considered, and from one applied water load sample to another. E. coli T(R) and that of S. saprophyticus were not significantly different (P> 0.05) for the two soil columns. V. parahaemolyticus T(R) significantly differed from that of E. coli and S. saprophyticus through soil column CA (P< 0.01) when the highest water load was applied, and through soil column CB (P< 0.05) for each of water load applied. A relative hierarchical arrangement of retained cells based on the T(R) showed that V. parahaemolyticus was less retained through the 2 soil columns. S. saprophyticus in most cases was more retained than others. The physical properties of the bacterial cell must be taken into consideration when evaluating the transfer of bacteriological pollutants towards groundwater.

Published
2010
Full Text
View/download PDF

5. Photoinactivation of Staphylococcus aureus and Vibrio parahaemolyticus in the model aquatic microcosm: effect of light intensity and dissolved biodegradable organic compound.

Author

Nola M, Matchim AG, Mobili OB, Nougang M, Krier F, Chihib NE, Hornez JP, and Njiné T

Subjects
Glucose analysis, Models, Chemical, Oxidation-Reduction, Solubility, Staphylococcus aureus drug effects, Staphylococcus aureus radiation effects, Vibrio parahaemolyticus drug effects, Vibrio parahaemolyticus radiation effects, Humic Substances analysis, Photolysis, Staphylococcus aureus growth & development, Ultraviolet Rays, Vibrio parahaemolyticus growth & development, Water Purification methods
Abstract

The impact of light (1,000 × 100,000 lx) on the inactivation of S. aureus and V. parahaemolyticus has been assessed under different concentrations of dissolved biodegradable organic compound (BOC) at pH 7.0. First, a gradual decrease in the number of cultivable cells was observed. Secondly, a cell reactivation was observed and it was marked in the absence of BOC. In the absence of BOC, the lowest value of cell inhibition rate (CIR) during the first 3 h was 0.138 h(-1) for S. aureus and 0.218 h(-1) for V. parahaemolyticus. In the presence of 10,100 and 1,000 mg/l of BOC, it was 0.196 h(-1), 0.243 h(-1) and 0.257 h(-1) for S. aureus respectively, and 0.285 h(-1), 0.306 h(-1) and 0.409 h(-1) for V. parahaemolyticus respectively. The CIRs values of each bacterial species significantly varied (P<0.001) with the changes in BOC concentration. In most cases, no significant difference was noted in the CIRs of both species when they were under the same light intensity and BOC. Nevertheless, it seems important to consider the impact of dissolved BOC during the treatment of bacterial polluted water.

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results