Team:Wageningen UR/Wetlab

iGEM Wageningen 2021

Wetlab

Engineering Photo

Cattlelyst is built on three pillars: Methane oxidation, Ammonia removal, and Safety. Each pillar encompasses several wetlab projects. Below all seven projects are listed.
If you are interested to learn more, press the buttons below!

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Synthetic methane oxidation in Escherichia coli

Soluble and particulate methane monooxygenase, and methanol dehydrogenase were expressed in C1 auxotrophic E. coli strains, connecting this C1-molecule to an efficient conversion pathway from methane biomass and carbon dioxide.

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Synthetic nitrification in Pseudomonas putida

Nitrification genes originating from autotrophic nitrifier Nitrosomonas europaea were expressed in P. putida. This allows P. putida to convert ammonia to hydroxylamine and subsequently nitrite, the first steps in the conversion of ammonia to dinitrogen in our biofilter.

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Synthetic denitrification in Pseudomonas putida

Denitrification genes originating from several native denitrifiers were expressed in P. putida. This allows P. putida to convert nitrate or nitrite to dinitrogen gas via the intermediates nitric oxide and nitrous oxide. These are the final steps in the conversion of ammonia to dinitrogen in our biofilter.

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Limiting nitrous oxide production in Pseudomonas putida

Steady nitrogen conversions are ensured by redirecting the electron flux towards the denitrification machinery in P. putida. This was realized by establishing a denitrification machinery or downregulating the native  ability of P. putida to respire with oxygen, in parallel.

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Methane-dependent kill switch in Escherichia coli

This kill switch couples methane concentration to a toxin-antitoxin system in E. coli. Should the bacterium escape the biofilter, the methane concentration would drop, leading to toxin production and cell death.

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Proximity-dependent kill switch in a microbial coculture

This kill switch kills P. putida and Escherichia coli upon escape from the biofilter. Outside the biofilter, they lose the close proximity to each other, activating the kill switch.

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Bacterial co-dependency

A co-dependency was established between E. coli  and P. putida by creating a cross-feeding community. The cross-feeding is based on amino acid exchange/auxotrophy and a carbon-source dependency.

About Cattlelyst

Cattlelyst is the name of the iGEM 2021 WUR team. Our name is a mix of 1) our loyal furry friends, cattle, and 2) catalyst, which is something that increases the rate of a reaction. We are developing “the something” that converts the detrimental gaseous emissions of cattle, hence our name Cattlelyst.

Are you curious about our journey? We have written about our adventures in our blog, which you can find here: