Functional Microbial Supercollector: VAULTer I
Our goal was to maximize sodium accumulation in S. cerevisiae. With our measurements we successfully proved that our design leads to higher sequestration of sodium. A yeast mutant taking up 5x more NaCl than the native wildtype, sequestrating 39% (6g/L) of the NaCl of a media containing 0.6 M NaCl (equal to seawater salinization).
Concept: Microbial Supercollector
Many different pollutive ions threaten the earth environment. Means there are varying demands for purifying ions, e.g. wastewaters. To tackle this issue, we developed a concept of microbial supercollectors adaptable to more than just Na+. To proof the adaptability, we additionally designed and tested a mutant capable of sequestrating potassium.
We developed a fundamental design for an application in wastewater treatment, including nutrition, separation and after-use of yeast. Regarding the process, but also in terms of safety and responsibility, it is crucial to separate yeast and water. We validated ultrafiltration as a convenient method for that, so we avoid environmental harm through the spreading into the environment of the sequestrated ions.
Through many talks and educational work, we initiated a debate on genetic engineering in Germany.
Assembled and submitted a tested and functional BioBrick
We created a Biobrick of the Na+/H+ antiporter AtNHXS1 which occurs in the membrane of vacuoles and is one of the most important transporters in our project. The sodium uptake of S.cerevisiae containing the AtNHXS1-gen is doubled, the chloride-uptake is three times as high. Furthermore, the biobrick of AtSultr1;2, a high-affinity sulfate transporter, represents the expansion of our project from NaCl to the additional accumulation of other salts. – Both biobricks are sequenced.
And what went wrong?
- We underestimated the effort to genetically modify yeast, therefore we could not implement and test all combinations of modifications which we planned at the beginning.
- The measurement of the chloride content failed for a few mutants due to the difficult detection of chloride in YPD.
- We indented to develop several BioBricks but didn’t accomplish all of them due to time limitation.
- We could not realize every idea due to the lack of cooperation with some corporate partners.