Microbial surfaces

An alternative packaging is the combination of food-packaging materials with antimicrobial substances to control microbial surface contamination of foods. For both migrating and nonmigrating antimicrobial materials, intensive contact between the food product and packaging material is required and therefore potential food applications include especially vacuum or skin-packaged products (Vermeiren and others 2002). 

Flocculation of microorganisms is thought to be affected by a bridging mechanism of polymers excreeted by the microorganisms or exposed to the microbial surface under suitable physiological conditions. More recently new work on adhesion of bacteria have been carried out (Van Loosdrecht et al., 1990) see Chapter 7.9. 

It has also been demonstrated that the transmembrane potentials of prokaryotes are typically 50% greater than their eukaryotic counterparts. This chemiosmotic potential has been proposed to act electrophoretically on host defense peptides attached to the microbial surface. It should also be noted that although increased cationicity of the host defense peptides is generally associated with increased antimicrobial activity there is a threshold by which selectivity between host and microbial cells is lost at the behest of increased cationicity. 

Warren, L.A. Ferris, F.G. (1998) Continuum between sorption and precipitation of Fe(III) on microbial surfaces. Environ. Sci. Techn. 

An additional microbial surface property that is of critical importance to successful bioremediation of subsurface pollution is transport through soil. Studies on the movement of bacteria through soil with moving water indicated that several properties are involved (Gannon, Manilal Alexander, 1991), including cell size, hydrophobicity, and net surface electrostatic charge. 

Smith, H. (1977) Microbial surfaces in relation to pathogenicity. Bacteriol. Rv. 41 475-500... 

Although exopolysaccharides do not normaUy have a structural role, they do form structures that can be detected by either light or electron microscopy. Exopolysaccharides may form part of a capsule closely attached to the microbial surface, or appear as loose slime secreted by the cell but not directly attached to it Exopolysaccharide producing cells usually form mucoid colonies on solid media and liquid cultures of these cells may become very viscous. However, growth conditions can influence the composition, physical properties and organisation of exopolysaccharide. 

Microorganisms in nature tend to accumulate at interfaces. In the oceans, they are more concentrated at the air-sea and sediment-sea interfaces than in the main body of water. In soils and on rock surfaces, they are not uniformly distributed but accumulate in discrete microcolonies attached to mineral surfaces or organic particulates to form a system composed of more or less discontinuous microcolonies, each in its own distinct microhabitat (Stotsky, 1972). Microorganisms can easily and rapidly penetrate cracks, joints and microscopic fissures in rock (Webley et al., 1963 Myers and McCready, 1966). Initial attachment of microorganisms to mineral surfaces is thought to be a sorptive process which depends upon the nature of the mineral and microbial surfaces and the physical and chemical characteristics of the aqueous phase (Marshall, 1971). 

Vincent E, Yuan Y, Hammann J, Hurdequint H, Guevara F (1996) Glassy dynamics of nanometric magnetic particles. J Magnet Magnetic Mater 161 209-219 Wang J-S, Swendsen RH (1990) Cluster Monte Carlo algorithms. Physica A 167 565-579 Warren LA, Ferris FG (1998) Continuum between sorption and precipitation of Fe(3) on microbial surfaces. Environ Sci Technol 32 2331-2337... 

Receptors for complement proteins that serve as leucocyte activators (e.g. C3a and C5a see section 2.2.4) or complement proteins that serve to coat (to opsonize) microorganisms (e.g. C3b). An opsonized microbial surface more readily adheres to a phagocyte membrane, with the opsonin triggering enhanced activity of the phagocyte itself. 

Ceramics Titania Anti-microbial surfaces, bioactive Ti surface oxide, dental implants Bioactive Zhao and Xiang (2012) and Kaluderovic, Schreckenbach and Graf (2014)... 

Analysis Methods for Liquid Impinger Solutions or Air Filter Samples Immunoassay Methods for Microbial Surface Antigens... 

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