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This study aimed to assess the biofilm formation by Bacillus cereus on two novel surfaces namely: aluminum and cold steel in comparison study with stainless steel and polystyrene. Also, it aimed to study the inhibitory effect of a new strain Pediococcus acidilactici against biofilm formation by B. cereus grown on these surfaces. In this study, B. cereus M50 isolated from milky machine surface was selected as the highest biofilm producer. The number of M50 cells adhered to aluminum and stainless steel surfaces were more than that adhered to polystyrene and cold steel, respectively. The antimicrobial, anti-adhesive and SEM studies revealed that the P. acidilactici P12 culture and its cell free filtrate showed a significant potential inhibition of biofilm formation of M50 on all tested surfaces under different conditions. These results demonstrated that P. acidilactici strain are considered a new biotreatment for biofilm destruction of food borne pathogens, food biopreservation and food safety. [ABSTRACT FROM AUTHOR]

In the present study, the behaviors of Newtonian and shear-thinning non-Newtonian droplets impinging on heated hydrophilic and hydrophobic surfaces have been investigated numerically using Ansys-Fluent. In this context, the volume-of-fluid technique is applied to track the free-surface of the liquid, and variable time-step is also utilized to control the Courant number. Furthermore, we have considered the dependence of viscosity, density and surface tension on temperature during the simulation. The results are compared to available experimental data at the same conditions, such as boundary conditions. The results demonstrate that there is a good agreement between the obtained results and the experimental trends, concerning normalized diameter profiles at various Weber numbers. Therefore, the focus of the present study is an assessment of the effects of variations in Weber number, contact angle and surface temperature for Newtonian and non-Newtonian liquids on dynamics behavior of droplet in collision with hydrophobic and hydrophilic surfaces. The results represent that the behaviors of Newtonian and non-Newtonian droplets are totally different, indicating the droplet sensitivity to the working parameters. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the ability of 15 serotypes of Salmonella to form biofilm on polystyrene, polyvinyl chloride (PVC) and glass surfaces. .Initially slime production was assessed on CRA agar and hydrophobicity of 20 Salmonella strains isolated from poultry and human and two Salmonella enterica serovar Typhimurium references strains was achieved by microbial adhesion to n-hexadecane. In addition, biofilm formation on polystyrene, PVC and glass surfaces was also investigated by using MTT and XTT colorimetric assay. Further, distribution of Salmonella enterotoxin (stn), Salmonella Enteritidis fimbrial (sef) and plasmid encoded fimbrial (pef) genes among tested strains was achieved by PCR.Salmonella strains developed red and white colonies on CRA and they are considered as hydrophilic with affinity values to n-hexadecane ranged between 0.29% and 29.55%. Quantitative biofilm assays showed that bacteria are able to form biofilm on polystyrene with different degrees and 54.54% of strains produce a strong biofilm on glass. In addition, all the strains form only a moderate (54.54%) and weak (40.91%) biofilm on PVC. PCR detection showed that only S. Enteritidis harbour Sef gene, whereas Pef and stn genes were detected in S. Kentucky, S. Amsterdam, S. Hadar, S. Enteritidis and S. Typhimurium.Salmonella serotypes are able to form biofilm on hydrophobic and hydrophilic industrial surfaces. Biofilm formation of Salmonella on these surfaces has an increased potential to compromise food safety and potentiate public health risk.

The numerical modeling of contact angle and wetting surface properties is investigated with volume of fluid (VOF) interface tracking method. A method is proposed to model the wetting properties with an existing continuum surface force (CSF) approach by introducing an original smooth volume of fluid function (SVOF) resulting from the solving of a penalized Helmholtz equation. For the diffusion equation proposed here, the interest of the penalty method is to account implicitly for wetting effects and, to avoid introducing sliding laws for the velocities at the wall or modifying by hand the interface shape on the solid boundaries. The SVOF model is validated and evaluated on published experiments concerning droplet impacts on flat and inclined surfaces with various wetting properties. [ABSTRACT FROM AUTHOR]

This study aimed to assess the biofilm formation by Bacillus cereus on two novel surfaces namely: aluminum and cold steel in comparison study with stainless steel and polystyrene. Also, it aimed to study the inhibitory effect of a new strain Pediococcus acidilactici against biofilm formation by B. cereus grown on these surfaces. In this study, B. cereus M50 isolated from milky machine surface was selected as the highest biofilm producer. The number of M50 cells adhered to aluminum and stainless steel surfaces were more than that adhered to polystyrene and cold steel, respectively. The antimicrobial, anti-adhesive and SEM studies revealed that the P. acidilactici P12 culture and its cell free filtrate showed a significant potential inhibition of biofilm formation of M50 on all tested surfaces under different conditions. These results demonstrated that P. acidilactici strain are considered a new biotreatment for biofilm destruction of food borne pathogens, food biopreservation and food safety., Competing Interests: Compliance with ethical standardsThere is no conflict of interests regarding the publication of this paper.

Background: The aim of this study was to evaluate the ability of 15 serotypes of Salmonella to form biofilm on polystyrene, polyvinyl chloride (PVC) and glass surfaces. ., Methods: Initially slime production was assessed on CRA agar and hydrophobicity of 20 Salmonella strains isolated from poultry and human and two Salmonella enterica serovar Typhimurium references strains was achieved by microbial adhesion to n-hexadecane. In addition, biofilm formation on polystyrene, PVC and glass surfaces was also investigated by using MTT and XTT colorimetric assay. Further, distribution of Salmonella enterotoxin (stn), Salmonella Enteritidis fimbrial (sef) and plasmid encoded fimbrial (pef) genes among tested strains was achieved by PCR., Results: Salmonella strains developed red and white colonies on CRA and they are considered as hydrophilic with affinity values to n-hexadecane ranged between 0.29% and 29.55%. Quantitative biofilm assays showed that bacteria are able to form biofilm on polystyrene with different degrees and 54.54% of strains produce a strong biofilm on glass. In addition, all the strains form only a moderate (54.54%) and weak (40.91%) biofilm on PVC. PCR detection showed that only S. Enteritidis harbour Sef gene, whereas Pef and stn genes were detected in S. Kentucky, S. Amsterdam, S. Hadar, S. Enteritidis and S. Typhimurium., Conclusion: Salmonella serotypes are able to form biofilm on hydrophobic and hydrophilic industrial surfaces. Biofilm formation of Salmonella on these surfaces has an increased potential to compromise food safety and potentiate public health risk.