Team:Toulouse/Design
Device
TrApiColi has been designed in order to take into account ethical
reflection, safety and ease of use for beekeepers. The use of
genetically modified organisms in a field, and because our project is associated with
edible products, underlies both applying of regulations and public interest.
In this context, as explain above, we searched a solution being able to isolate our engineered bacteria from
the environment, but allowing its growth, metabolism and gas diffusion. We found the
project of the iGEM Groeningen 2012 team which used the polymer TPX® in
order to contain their bacteria separated of the meat [1]. Thus, we
decided to ask them TPX® characteristics. We finally contacted the TPX® supplier Mitsui Chemicals. We obtained
some samples of TPX® by contacting the company MitsuiChemicals. TPX®, Polymethylpentene (4-methylpentene-1 based polyolefin, Mitsui Chemicals, Inc.), is a polymer.
To check if our device can be safe and feasible, several tests have been performed:
- Safety test: Impermeability of bacteria through the bag of TPX®
- Gas diffusion tests: Permeability of butyric acid and formic acid through the bag of TPX®
- Growth tests in TPX®: Culture of the strain E. coli BW25113 can grow in a TPX® bag (ie. in microaerobic conditions, without agitation and miming batch culture condition), as it would be in the field
- Bacterial survival over 15 days in microaerobic condition
- Carbone source test: choice of Carbon source to produce acids during 10 days
- Acid toxicity on E. coli
Trap Construction
Our goal is to create a solution against varroas. In order to use ApiColi to treat varroosis, we designed a trap, named TrApiColi.
Since the production of the two pathways are regulated by day light, our bacteria need to be outside of the beehive. Thus, the trap was made to be placed at the entrance of the hive, in order to prevent the entry of the mites.
TrApiColi is composed of four main parts:
1. A grid in line with the bottom board
The bees usually enter the hive by landing on the bottom board before walking inside. Because of the alignment of the trap with the board, it does not disturb the bee’s comings and goings. The holes are big enough to let the varroas fall through them, but not the bees.
The four different parts of our trap
2. 2) A funnel, to channel all the falling varroas
The grid and the funnel
TPX Bag
