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- | == Self assembling hydrophobic biofilm ==
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- | Surface hydrophobicity is a very useful property and is used in many applications ranging from raincoats, antifouling coatings, anti-bacterial and anti-fungal coatings and applications in the field of biomedical sciences to protection of highly sensitive sensor equipment. Hydrophobicity keeps a surface water free en thereby clean and dry, this prevents micro-organisms from fouling surfaces and corrosion from forming. Most hydrophobic coatings used today involve costly chemical coating treatments or production of expensive and sometimes toxic hydrophobic molecules. So why not create an organism that does the work for you.
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- | The idea is to engineer a bacterium that once applied on a surfaces, starts forming a fast growing rigid biofilm. Completion of the biofilm will trigger the expression of hydrophobic proteins by the biofilm forming bacterium. These hydrophobic proteins will be incorporated in the rigid biofilm, causing strong hydrophobic surface activity . Exposure to UV light could then trigger a kill switch, initiating the dieing of the bacteria and discolouring of the biofilm. The result of these processes will be a surfaces that is coated by a rigid biofilm with embedded hydrophobic proteins, leaving the coated surface extremely hydrophobic.
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- | Producing a hydrophobic biocoating that is self assembling, would have a lot of advantages.
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- | First it is relatively cheap to apply bacteria to surfaces. and since the coating process will be done by the bacteria themselves, there is no high-tech treatment involved and there are no expensive chemicals necessary to attain the hydrophobicity.
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- | Secondly because these hydrophobins are proteins, they are in contrast to many chemical hydrophobins non-toxic to the environment. Applications of this hydrophobic bio film could range from non toxic antifouling coatings on ships, antifungal coatings and corrosion and water protecting coatings.
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- | == Backup project ==
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- | [[Image:conjuga.jpg|200px|thumb|right|Fig. 1. Bacterial conjugation]]
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- | Antibiotic resistance is a major problem in both the medical and agricultural sector.
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- | This project aims to create a harmless bacterial strain that spreads a debilitating conjugation vector through a potentially pathogenic bacterial population.
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- | The conjugation vector carries a mutated CheY gene (Scharf ''et al''., 1997) that continuously signals the flagellar FliM protein and induces clockwise rotation of the flagellum, causing the bacteria to tumble constantly.
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- | The immobilized bacteria may also secrete an attractant (encoded on the vector) to attract more bacteria and spread the conjugation vector.
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- | To ensure spreading of the vector through more distant populations the initial bacterial strain carries a genomically encoded repressor that represses the genes inserted on the conjugation vector (fig. 2).
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- | This way the bacterium is still mobile and can adapt to environmental changes, like the bacteria it is supposed to transfer the vector to.
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- | [[Image:schema.png|200px|thumb|left|Fig. 2. Mechanism]]
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- | Scharf BE, Fahrner KA, Turner L, Berg HC. Control of direction of flagellar rotation in bacterial chemotaxis. Proc Natl Acad Sci U S A. 1998;95:201–206. [http://www.ncbi.nlm.nih.gov/pubmed/9419353 PubMed]
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