Projects / Programmes
Microbial adhesion management on material surfaces
| Code |
Science |
Field |
Subfield |
| 1.02.07 |
Natural sciences and mathematics |
Physics |
Biophysics |
| Code |
Science |
Field |
| B002 |
Biomedical sciences |
Biophysics |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
microorganisms, adhesion, contact surfaces
Researchers (20)
Organisations (5)
Abstract
Interactions between microorganisms and material surfaces play an important role in biology and different technologies like food, pharma and service technology. The adhesion of microorganisms to various surfaces starts with the initial attraction of the cells to the surface followed by adsorption. The adhesion process is governed by physical and chemical interactions between microorganism and surface and represents the first step in microorganism colonization as well as bio-film formation. This phenomenon has direct and indirect influence on human health and environment. On microbial adhesion and colonization on flat surfaces there is a strong influence of various parameters such as properties of microbial cell (cell surface hydrophobicity and charge, extracellular appendages, extracellular polymeric substances, signaling molecules) and fluid (polarity, flow velocity, pH, ionic strength, temperature, presence of salts, antimicrobials, nutrient availability) and surface chemistry (hydrophobicity, electric charge, surface roughness).
The objective of this study is to investigate the influence of surface roughness and hydrophobicity on the degree of bio particles adhesion and the subsequent formation of biofilm. Atomic force microscopy (AFM) will be used for the characterization of the surface topography of the material. We will focus on two different types of surfaces stainless steel material of different surface treatments and coatings. Both are important for SME partner involved. We will consider the influence of surface roughness on bio particles adhesion whereas the surface hydrophobicity will be kept constant as possible. In the second study the hydrophobicity of polymer coatings on smooth metal surface will be varied. Such contact materials will be exposed to variation of physical, biological and environmental parameters which will include variation of biological micro particles as relevant environmental parameters which can enhance or reduce attachment kinetics and strength. The experiments will include selection of pathogenic and spoilage microorganisms. The expected outcome of this project is knowledge about physical, biological and environmental parameters which has to be managed to control pathogenic and spoilage microorganism transmission via contact surfaces in food and pharma production.
The ambition of this project is to select relevant materials and precisely characterize contact material surface respecting different production treatments. We will study microbiological features and select the most appropriate methodology for studying microbial-material surfaces interactions. We aim to study the influence of environmental factors on microbial attachment and biofilm formation. In the final stage we will use these methodological approaches to study the efficiency of physical, chemical and biological treatments as well as the “hurdle concept” for prevention of microbial adhesion.
Using AFM the surfaces of differently prepared samples will be fully characterized. We expect that the surface roughness influences the increase of the microorganism’s adhesion, probably to the larger available surface area. Further we will select and optimize a method that allows an identification of selected microorganisms on selected materials (Scanning electron microscopy (SEM) images and stereology methods). We also expect that the chosen conditions will be suitable for studying the adhesion on different surfaces tested in the experiment and at the same time simulating the natural conditions for forming biofilms in industry. Finally, we expect to be able to select the most efficient combination of contact surface preparation and subsequent treatment(s) for prevention of microbial adhesion which will (a) not induce microbial viable but non culturable (VBNC) formation, (b) not introduce a risk of bacterial resistance development, (c) reduce water consumption and/or (d) not produce toxic chemical residues.
Significance for science
In the project “Microbial adhesion management on material surfaces” we investigated the influence of surface roughness and hydrophobicity on the degree of microbial adhesion and the subsequent formation of biofilm. Although the project was applied we obtained new scientific knowledge. The results were published in two international scientific papers with impact factor and in one book chapter. New scientific findings open new possibilities for further research. Within the project we developed a new method for measuring the bacterial adhesion rate on metal surfaces. New flow chamber was developed and constructed. With the chamber we studied the influence of laminar and turbulent liquid flow on the detachment of bacteria adhered to the metal surface. This project gives new knowledge about biofilms which is important for development of new contact surfaces in different disciplines related to process industry and medicine. All acquired knowledge will enable further research in this field.
Significance for the country
Our experiments were performed with bacterial strains isolated in Slovenia, i.e. P. aeruginosa ŽMJ87, Staph. aureus ŽM72 and L. monocytogenes ŽM520. The study of bacterial adhesion and biofilm formation is especially important to ensure food safety and consumer health protection. It is also important for the environment where it is expected to maintain an aseptic environment like in the food industry, pharmaceutical industry and health care. Monitoring the presence of individual microbial strains may be used in the upgrading of sanitation procedures in the HACCP system. In our research we should stress the importance of surface treatments. As an example we mention stainless steel surfaces AISI 304/316 with different surface treatments. During our research we found that the specific surface treatments may substantially decrease the microbial adhesion. The appropriate material selection can contribute to more reliable sanitation procedures and to better control of the biofilm formation. The technological processes in the stainless steel production represent additional costs and can significantly increase the price of the final product. We note that some complex surface treatments increase the price of the final products but parallel does protect bacterial adhesion and subsequent biofilm formation. Our research showed that not adequate chosen technology can increase the price of the stainless steel production and therefore decrease the competitiveness on the market.
Most important scientific results
Annual report
2012,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2012,
final report,
complete report on dLib.si
