iGEM Groningen 2015 wants to harness the energy of salinity, often called ‘Blue Energy’. The Dutch Institute for Water Technology Research (Wetsus) is constructing a blue energy test plant at the Afsluitdijk, where the fresh water of the Ijsselmeer and the salt water of the Waddenzee are easily combined. Blue energy has no waste products. It is estimated that blue energy could supply 7% of the world energy need.
Membranes
The biggest problem with the current Blue Energy technology lies in the ion exchange membranes that are used. They are expensive and unreliable. We want to use bacteria to create a living membrane that can repair itself.
Bacteria
The bacteria we selected is the biofilm forming Bacillus subtilis strain 3610 ComI. By overexpressing tasA, bslA, pgs BCA we aim to modulate this B. subtilis strain in such a way that its biofilm becomes more rigid and negatively charged. These adaptations should protect the biofilm against the flow of water and promote ion-selectivity, respectively. To regulate the overexpression of these genes, we place it under control of a salt dependent promotor: proH. This promotor ensures that the modificated genes are only expressed when the biofilm is exposed to sea water. In addition, we will overexpress epsE to prevent swarming of B. subtilis under water. In result, we will possibly create the first biological membrane that can generate blue energy.
