utilisation of bacteria for anti-fouling biofilm able to avoid the settlement and growth of...
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Utilisation of bacteria Utilisation of bacteria for anti-fouling biofilm for anti-fouling biofilm
able to avoid the able to avoid the settlement and growth settlement and growth
of micro¯o of micro¯o organismsorganisms
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Fouling mechanism
• 1: adherence of bact. Colony (Van der Waals)
• 2: anchoring (pilis)
• 3: polysaccharide matrix
• 4: M.O. Attachment
• 5: More fouling
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State of research...
• Study of inhibitory effect of various bact. strains on various M.O.
• Characterization of attachment mechanism of fouling agents
• Characterization of inhibiting extracellular products
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Advantages/drawbacks
+ -
Up to 90 % inhibition of MO
Many different MO types → effect limited to spec. species
No toxic paint on hulls Mutations: cancel inhib. effect
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Feasibility• Genetically: ?• Sea: very complex medium• Need significant upstream research
(surface materials, ) • Need experimental validation of designed
bacteria with many different conditions → more time than actual engineering ?
• Lots of economical interest in this
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Bacteria used
• Alteromonas
• Pseudoalteromonas : extensively studied for its anti-fouling activity
=> Inhibit the settlement and growth of a large number of organisms
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Anti-fouling substance produced
• Protein or peptide• Thermostable• Hydrophilic• >3500 daltons in molecular size
Inhibition of settlement by 2 ways:- direct: induce lysis in cultures- Indirect: emission from the bacteria of chemical
products which inhibit growth and settlement
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Two possibilities
1. Continuous secretion of a given molecule which will avoid the deposit of molluscs on the hull
1. Secretion in response to a given input (e.g. shear stress)
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Description of the bioparts
1. Input: when bacteria sense an external input, triggering of the production of a certain molecule to avoid the deposit of plants and mollusc, for example in response to pressure => possibility to use luxR for example for the modelisation = inducible promoter, normally off, which turn on in response to an external input
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Description of the bioparts
2. Output: the bacteria can produce a molecule in order to kill molluscs attached or to prevent the adhesion.
=> possibility to use something like GFP as an output in our modelisation
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Description of the bioparts
• 3. Filter: need to avoid the noise
coherent feedforward loop with AND-gate.
Input fast degrading primary messenger stable secondary messenger AND-gate