Team:York/Description

Project Description

What is eutrophication?

This year we have chosen to come up with a solution that targets the root of the problem of eutrophication - where too much phosphate in water bodies leads to algal blooms. These blooms disrupt local ecosystems by causing ‘dead zones’ which causes species loss. The input of wastewater and therefore phosphate into these bodies is a large contributing factor to the issue.

How are we fixing it?

Phosphate removal from wastewater is a considerable challenge that we hope to solve with biological agents as an alternative to chemical treatment. Our project builds upon the ideas of enhanced biological phosphate removal (EBPR) in which bacteria known as polyphosphate accumulating organisms (PAOs) in activated sludge acquire phosphate inside their cells. However these current microbiological tools are inefficient and we feel that designing a bacterium to remove phosphate will be much better suited to the task.

Who is Phil?

Our team is working on exploiting the natural abilities of Escherichia coli to uptake phosphate. By studying its phosphate metabolism, we aim to improve E.coli‘s phosphate uptake from the environment and therefore engineer a bacterium that can be used as a better alternative to the current methods used by wastewater facilities. For this our team is looking into the genes responsible for phosphate transport and polyphosphate kinases (PPK) to allow the luxury uptake of phosphate into the E.Coli cells. We plan also to borrow genes from different organisms to enhance the natural bioremediation processes that already exist in our model. Our bacterium should be both efficient and stable for high levels of phosphate uptake.

We envisage our project to be a part of many future applications relating to the uptake and recovery of phosphate, with the possibility of being integrated byindustry and with other projects.

Improving a past team's BioBrick:

As part of our construct, we used a BioBrick from Hong Kong University's 2013 iGEM team. BBa_K1217002 is a coding sequence from Kingella oralis known as ppk1 that encodes a polyphosphate kinase. We submitted a new BioBrick BBa_K1807006 that contains HKU's coding sequence that can be used as a KoPPK gene expression device. It has been characterised and sequenced.

In addition we characterised BBa_E0038, a coding sequence for lacZ peptide by including it in our BBa_K1807000 construct. This construct was used to assemble all of our expression devices we made. This part initially had missing functionality on the registry database, and we are now the first iGEM team on record to use this version of the lacZ alpha peptide. We retrieved it from the example database and demonstrated that it is functional for blue-white screening. Initially this biobrick was used in an experiment to make a bifunctional enzymatic and fluorescent reporter of gene expression (Martin et al, 2009). They used the following promoters: BBa_J23119, BBa_J23101, BBa_J23106, BBa_J23115 (in order of decreasing strength) of which all are constitutively active, wheras ours is IPTG inducible. Their ribosome binding site brick was BBa_B0032, which is only 33.96% of BBa_B0034, the BioBrick we used in our construct. In addition, they used a low copy vector- BBa_PSB4A5, the opposite of our high-copy BBa_PSB1C3.

Reference: Martin, Lance, Austin Che, and Drew Endy. "Gemini, a bifunctional enzymatic and fluorescent reporter of gene expression." PLoS One 4.11 (2009): e7569.