Laboratoire Of Biotechnologie Microbienne

Timezgana, Morocco

Laboratoire Of Biotechnologie Microbienne

Timezgana, Morocco
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Hamadi F.,University Ibn Zohr | Hamadi F.,Sultan Moulay Slimane University | Asserne F.,Sultan Moulay Slimane University | Elabed S.,University Sidi Mohammed Ben Abdellah | And 5 more authors.
Food Control | Year: 2014

Staphylococcus aureus has the ability to adhere and to form biofilm on inert surface such as stainless steel commonly used in food industry. The biofilm formed on the surface of milk processing equipments could be a source of dairy products contamination. This contamination causes a food poisoning. In this paper the S.aureus adhesion on stainless steel treated by three types of milk (ultrahigh-temperature (UHT)-treated milk; UHT skimmed milk, UHT semi-skimmed milk) was investigated.Stainless steel was exposed to three types of milk with a different amount of fat component. Contact angles measurements were used to determine the surface physicochemical properties of substratum treated with the three milk products. The hydrophobicity and electron acceptor properties of stainless steel seem to be decreasing with the amount of fat component present in milk but its electron donor property increase with this component. The ability of S. aureus to adhere to stainless steel treated and untreated with milk was also examined. Treatment with the three types of milk reduces bacterial attachment. On treated substratum, the adhesion extent was affected by the type of milk and consequently by the amount of fat component. The lower and the higher adhesion were obtained when the steel was treated by the UHT semi-skimmed milk and UHT skimmed milk respectively. The correlation between physicochemical properties and S.aureus adhesion show that this latter was controlled by hydrophobicity and electron donor properties.The findings of this work can contribute to develop strategies for prevent S.aureus adhesion on stainless steel and biofilm formation. Also they could be taken into account in cleaning and disinfection procedures. © 2013 Elsevier Ltd.


Kadri Z.,French National Center for Scientific Research | Kadri Z.,Laboratoire Of Biotechnologie Microbienne | Amar M.,French National Center for Scientific Research | Ouadghiri M.,French National Center for Scientific Research | And 4 more authors.
International Journal of Systematic and Evolutionary Microbiology | Year: 2014

Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682Tand LMG 27684T, were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07T as their closest phylogenetic neighbour (95.9 % and 95.7 % similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7 %. Although strains LMG 27682Tand LMG 27684T shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68 %), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682T = CCMM B831T) and Streptococcus rifensis sp. nov. (type strain, LMG 27684T = CCMM B833T) are proposed. © 2014 IUMS.


PubMed | Ghent University and Laboratoire Of Biotechnologie Microbienne
Type: Journal Article | Journal: Antonie van Leeuwenhoek | Year: 2015

Four lactic acid bacteria isolates obtained from fresh dromedary camel milk produced in Dakhla, a city in southern Morocco, were characterised in order to determine their taxonomic position. The four isolates had highly similar MALDI-TOF MS and RAPD fingerprints and identical 16S rRNA gene sequences. Comparative sequence analysis revealed that the 16S rRNA gene sequence of the four isolates was most similar to that of Enterococcus sulfureus ATCC 49903(T) and Enterococcus italicus DSM 15952(T) (99.33 and 98.59% similarity, respectively). However, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes revealed that the taxon represented by strain LMG 28766(T) was well separated from E. sulfureus LMG 13084(T) and E. italicus LMG 22039(T), which was further confirmed by DNA-DNA hybridization values that were clearly below the species demarcation threshold. The novel taxon was easily differentiated from its nearest neighbour species through sequence analysis of protein encoding genes, MALDI-TOF mass spectrometry and multiple biochemical tests, but had a similar percentage G+C content of about 39%. We therefore propose to formally classify these isolates as Enterococcus bulliens sp. nov., with LMG 28766(T) (=CCMM B1177(T)) as the type strain.


El abed S.,Laboratoire Of Biotechnologie Microbienne | El abed S.,University Sidi Mohammed Ben Abdellah | Ibnsouda S.K.,Laboratoire Of Biotechnologie Microbienne | Ibnsouda S.K.,University Sidi Mohammed Ben Abdellah | And 4 more authors.
World Journal of Microbiology and Biotechnology | Year: 2012

Initial microbial adhesion to surfaces is a complicated process that is affected by a number of factors. An important property of a solution that may influence adhesion is pH. The surface properties of the cedar wood were characterized by the sessile drop technique. Moreover, the interfacial free energy of surface adhesion to the cedar wood was determined under pH values (2, 3, 5, 7, 9 and 11). The results showed that cedar wood examined at different pH levels could be considered hydrophobic ranged from Giwi = -13. 1 mJ/m2 to Giwi = -75 mJ/m2. We noted that the electron-donor character of cedar wood was important at both basic and limit acidic conditions (pH 11 and pH 3) and it decreased at intermediate pH (pH 5). The cedar wood substratum presents a weak electron acceptor under various pH's. In addition, the adhesion of conidia from Penicilllium expansum to the cedar wood surfaces at different pH values (2, 3, 5, 7, 9 and 11) was investigated using Environmental Scanning Electron Microscopy and image analysis was assessed with the Mathlab® program. The data analysis showed that the conidia from P. expansum were strongly influenced by the pH. The maximum adhesion occurs in the pH 11 and pH 3 and decreased to 24% at pH 5. © 2011 Springer Science+Business Media B.V.


Soumya E.A.,Laboratoire Of Biotechnologie Microbienne | Saad I.K.,Laboratoire Of Biotechnologie Microbienne | Saad I.K.,University Sidi Mohammed Ben Abdellah | Hassan L.,Laboratoire Of Valorisation Et Of Securite Des Produits Agroalimentaires | And 3 more authors.
African Journal of Microbiology Research | Year: 2011

Pseudomonas aeruginosa has a high propensity to develop biofilms that are resistant to exogenous deleterious agents. The aim of this study was to investigate whether carvacrol and thymol can interfere with adherence phenomena as well as acting on biofilm formation. Tests of P. aeruginosa strains showed that carvacrol and thymol interferes with the starting phases of adherence as well as with P. aeruginosa biofilms. Carvacrol and thymol (2MIC) inhibition was 97±8.5 and 89±6.3% for P. aeruginosa (ATCC 27853) and 72±4.6 and 69±6.8% for P. aeruginosa (CIP A22) adherence respectively. Carvacrol (2MIC) inhibition exceeds 90% for P. aeruginosa (ATCC 27853) and P. aeruginosa (IL5) biofilm. Thymol (2MIC) inhibition is 86±2.1, 54±5.9 and 70±4.3% for P. aeruginosa (ATCC 27853) P. aeruginosa (CIP A22), P. aeruginosa (IL5), respectively. © 2011 Academic Journals.


El-Abed S.,Laboratoire Of Biotechnologie Microbienne | El-Abed S.,University Sidi Mohammed Ben Abdellah | Houari A.,Laboratoire Of Biotechnologie Microbienne | Latrache H.,Laboratoire Of Valorisation Et Of Securite Des Produits Agroalimentaires | And 3 more authors.
Research Journal of Microbiology | Year: 2011

Biofilm control has become an area of intense study. The effect of four Essential Oil Components (EOC's) on adherence and biofilms on two pathogenic Pseudomonas aeruginosa isolates were investigated in this study. The inhibitory activity was tested on polystyrene flat-bottomed microtitre plates using the Crystal Violet (CV) staining assay. The results showed that this activity was dependent on the terpenes concentration used to treat the adherence and biofilm. Treatment of Pseudomonas aeruginosa adherence with eugenol, carveol and carvone (0.5 Minimum Inhibitory Concentration), resulted 60, 45 and 54% inhibition for P. aeruginosa (CIP A22) and 69, 65 and 42% for P. aeruginosa (ATCC 27853), respectively. β-ionone shows a slight inhibitory effect for the two strains studied. The results also showed that eugenol (0.5 Minimum Inhibitory Concentration) was able to induce an inhibition>90% of P. aeruginosa biofilm (strain ATCC 27853) and a concentration of carvone and carveol of at least 0.5 Minimum Inhibitory Concentration (MIC) was required to obtain approximately 50% of biofilm inhibition. β-ionone (0.5 MIC) appeared as the least efficient against P. aeruginosahiofilm resulted only 43% reduction of the biofilm. This study demonstrated the anti-adherence and antibiofilm activity of terpenes and points out the exceptional efficiency of eugenol, carvone and carveol, which could represent candidates in the treatment of Pseudomonas aeruginosa biofilm. © 2011 Academic Journals Inc.


Soumya E.,Laboratoire Of Biotechnologie Microbienne | Soumya E.,University Sidi Mohammed Ben Abdellah | Saad I.K.,Laboratoire Of Biotechnologie Microbienne | Saad I.K.,University Sidi Mohammed Ben Abdellah | And 2 more authors.
Materials Science and Engineering C | Year: 2013

In this study, the adhesion of 4 Penicillium strains (Penicillium granulatum, Penicillium crustosum, Penicillium commune and Penicillium chrysogenum) on cedar wood was examined qualitatively and quantitatively by using the extended DLVO (XDLVO) approach and the environmental scanning electronic microscopy (ESEM) technique. A comparison between the XDLVO theories and the ESEM technique was also investigated. The adhesion tests revealed that P. chrysogenum was not able to adhere on the cedar wood substrata, as predicted by the XDLVO approach. We have also found by ESEM that the three Penicillium strains (P. granulatum, P. crustosum, P. commune) adhered on wood, as not predicted theoretically. Moreover, the time of adhesion (3 h and 24 h) was used not only to compare the capacity of adhesion according to contact time but also to explain the discrepancies between the XDLVO approach prediction and the adhesion experiments. A positive relationship between the XDLVO approach and adhesion experiments has been observed after 3 h of adhesion. In contrast, a contradiction between the XDLVO predictions and the adhesion test results has been noted after 24 h of adhesion of Penicillium strains to the wood surface. © 2013 Elsevier B.V. All Rights Reserved.


Maataoui H.,Laboratoire Of Biotechnologie Microbienne | Barkai H.,Laboratoire Of Biotechnologie Microbienne | Sadiki M.,Laboratoire Of Biotechnologie Microbienne | Haggoud A.,Laboratoire Of Biotechnologie Microbienne | And 2 more authors.
Journal of Adhesion Science and Technology | Year: 2014

Physicochemical characterization of microorganism is very important in a wide range of scientific and technological fields. In this study, we reported the isolation and the molecular identification of actinomycetes recovered from cedar wood decay. The isolates named H5 and H8 were identified by 16S rDNA sequencing and were shown to belong to the genus Nocardia and Streptomyces, respectively. Furthermore, physicochemical proprieties including hydrophobicity, electron donor/acceptor, and the Lifshitz-van der Waals (γ LW) of these strains were evaluated using contact angle measurements. The results showed that Nocardia sp. (H5) had a hydrophobic (ΔGiwi =-78.56 mJ/m2) and a weak electron donor/acceptor character. In contrast, results from contact angle measurements showed that the surface free energy of Streptomyces strains (H2, H3, and H8) were ΔGiwi = 20.71 mJ/m2, ΔGiwi = 30.63 mJ/m2, and ΔGiwi = 15.35 mJ/m2, respectively, classifying these microorganisms as hydrophilic bacterium. Moreover, the three strains were predominantly electron donating (γ -) and exhibit a weak electron-accepting (γ +) character. © 2014 Taylor & Francis.


PubMed | Laboratoire Of Biotechnologie Microbienne
Type: Journal Article | Journal: World journal of microbiology & biotechnology | Year: 2012

Initial microbial adhesion to surfaces is a complicated process that is affected by a number of factors. An important property of a solution that may influence adhesion is pH. The surface properties of the cedar wood were characterized by the sessile drop technique. Moreover, the interfacial free energy of surface adhesion to the cedar wood was determined under pH values (2, 3, 5, 7, 9 and 11). The results showed that cedar wood examined at different pH levels could be considered hydrophobic ranged from Giwi = -13.1 mJ/m(2) to Giwi = -75 mJ/m(2). We noted that the electron-donor character of cedar wood was important at both basic and limit acidic conditions (pH 11 and pH 3) and it decreased at intermediate pH (pH 5). The cedar wood substratum presents a weak electron acceptor under various pHs. In addition, the adhesion of conidia from Penicilllium expansum to the cedar wood surfaces at different pH values (2, 3, 5, 7, 9 and 11) was investigated using Environmental Scanning Electron Microscopy and image analysis was assessed with the Mathlab() program. The data analysis showed that the conidia from P. expansum were strongly influenced by the pH. The maximum adhesion occurs in the pH 11 and pH 3 and decreased to 24% at pH 5.


PubMed | Laboratoire Of Biotechnologie Microbienne
Type: Journal Article | Journal: Materials science & engineering. C, Materials for biological applications | Year: 2013

In this study, the adhesion of 4 Penicillium strains (Penicillium granulatum, Penicillium crustosum, Penicillium commune and Penicillium chrysogenum) on cedar wood was examined qualitatively and quantitatively by using the extended DLVO (XDLVO) approach and the environmental scanning electronic microscopy (ESEM) technique. A comparison between the XDLVO theories and the ESEM technique was also investigated. The adhesion tests revealed that P. chrysogenum was not able to adhere on the cedar wood substrata, as predicted by the XDLVO approach. We have also found by ESEM that the three Penicillium strains (P. granulatum, P. crustosum, P. commune) adhered on wood, as not predicted theoretically. Moreover, the time of adhesion (3 h and 24 h) was used not only to compare the capacity of adhesion according to contact time but also to explain the discrepancies between the XDLVO approach prediction and the adhesion experiments. A positive relationship between the XDLVO approach and adhesion experiments has been observed after 3h of adhesion. In contrast, a contradiction between the XDLVO predictions and the adhesion test results has been noted after 24h of adhesion of Penicillium strains to the wood surface.

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