Utilisation of bacteria for anti-fouling biofilm able to avoid the settlement and growth of micro¯o organisms
Fouling mechanism 1: adherence of bact. Colony (Van der Waals) 2: anchoring (pilis) 3: polysaccharide matrix 4: M.O. Attachment 5: More fouling
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
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
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
Bacteria used Alteromonas Pseudoalteromonas : extensively studied for its anti-fouling activity => Inhibit the settlement and growth of a large number of organisms
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
Two possibilities Continuous secretion of a given molecule which will avoid the deposit of molluscs on the hull Secretion in response to a given input (e.g. shear stress)
Description of the bioparts 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
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
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