Difference between revisions of "Biofilms on food preparation surfaces"

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===Conditioning of a Surface===
 
===Conditioning of a Surface===
Biofilm formation can occur on any submerged surfaces in any environment with the present of bacteria. On food preparation surfaces, bacteria, inorganic and organic materials get adsorb on the surface leading to conditioned surfaces.  
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Biofilm formation can occur on any submerged surfaces in any environment with the present of bacteria. On food preparation surfaces, bacteria, inorganic and organic materials get adsorb on the surface leading to conditioned surfaces. The conditioning can alter physio-chemical properties of the surface, surface charge, surface free energy, surface hydrophobicity.
 
 
  
 
===Surface Charge and Hydrophobicity===
 
===Surface Charge and Hydrophobicity===

Revision as of 22:36, 10 April 2010

Introduction

Scanning electron microscopy photomicrograph of a 6 old B. cereus biofilm formed on a stainless steel surface. x 6330 magnification; bar = 5 micron.[1]

Biofilms are a consortium of microorganisms and extracellular substances in association with a solid surface in contact with liquid. It is nature of microorganisms to attach to wet surface, and form slimy layer composed of extracellular polymeric substances (EPS) to protect themselves from grazers and harsh environment. Biofilms can be beneficial or detrimental to the environment on which they form. For example, stream biofilm is capable of recycling organic matter. On the other hand, biofilms forming on food-contact surfaces can lead to hygienic problems and economical losses due to food spoilage. Food-contact surfaces can be a great habitat for food-borne pathogens because food preparation surfaces are usually in contact with organic matter such as milk which is a good source of nutrients for microorganisms, with inorganic debris, with other microorganisms. Once bacteria irreversibly attach to the surface, they produce EPS, which helps bind cells together, to the surface, and to other particulate materials. Cells also communicate between themselves to initiate antibiotic biosynthesis, and extracellular enzyme biosynthesis.

Physical environment

Biofilm formation 1)pre-conditioning of the adhesion surface 2)transport of planktonic celss from the bilk liquid to the surface 3)adsorption of cells at the surface 4)desorption of reversible adsorbed cells 5)irreversible adsorption of bacterial cells at a surface 6)production of cell-to-cell signal 7)transport of substrates to and within the biofilm 8)substrate metabolism by biofilm-bound cells and transport of products our of the biofilm 9)biofilm removal by detachment or sloughing

Conditioning of a Surface

Biofilm formation can occur on any submerged surfaces in any environment with the present of bacteria. On food preparation surfaces, bacteria, inorganic and organic materials get adsorb on the surface leading to conditioned surfaces. The conditioning can alter physio-chemical properties of the surface, surface charge, surface free energy, surface hydrophobicity.

Surface Charge and Hydrophobicity

cell surface hydrophobicity and the presence of extracellular filamentous appendages may influence the rate and the extent of microbial attachment.

filamentous appendages include flagella, pili, prosthecae and stalks

Surface Roughness

Stainless Steel as a Food Source Contact Surface

Subsection 1a

Subsection 1b

pH and Temperature

Oxygen Availability

Moisture

Biological interactions

Are there important biological interactions that are important in this environment? Do these interactions influence microbial populations and their activities? How do these interactions influence other organisms? Describe biological interactions that might take place in this environment, using as many sections/subsections as you require. Look at other topics available in MicrobeWiki. Create links where relevant.

Biofilm Ecosystem Development

Coaggregation and Aggregation

Subsection 1a

Subsection 1b

Conjugation

Subsection 1a

Subsection 1b

Intercellular Communication within Biofilm Communities

Quorum Sensing

Cell-to-Cell Communication

Microbial processes

What microbial processes define this environment? Describe microbial processes that are important in this habitat, adding sections/subsections as needed. Look at other topics in MicrobeWiki. Are some of these processes already described? Create links where relevant.

Extrcellular Polymeric Substances (EPS)

Key Microorganisms

What kind of microbes do we typically find in this environment? Or associated with important processes in this environment? Describe key groups of microbes that we find in this environment, and any special adaptations they may have evolved to survive in this environment. Add sections/subsections as needed. Look at other microbe listings in MicrobeWiki. Are some of the groups of microbes from your environment already described? Create links to those pages. Specific microbial populations will be included in the next section.

Listeria monocytogenes, Salmonella spp., Staphylococcus spp., Escherichia coli O157:H7

Listeria monocytogenes

important foodborne pathogen-listeriosis outbreak in Canada psychophilic bacteria- grow in refrigerated ready-to-eat food that may be contaminated during processing and packaging.

Pseudomonas spp.

the most important bacteria causing spoilage of conventionally pasteurize liquid milk products: 2 routes 1)raw milk- enzyme 2)post pasteurization milk

Examples of organisms within the group

List examples of specific microbes that represent key groups or are associated with important processes found in this environment. Link to other MicrobeWiki pages where possible.

Current Research

Approach for Biofilm Mitigation- biofilm prevention

Green Strategy for Biofilms Control

Cleaning and Removal of Biofilm

Microscopic Examination of Biofilms

Attachment of Microorganisms on Food Contacting Surfaces

Enter summaries of recent research here--at least three required

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Angela Kent at the University of Illinois at Urbana-Champaign.