Difference between revisions of "Team:Glasgow/Practices"

We conducted a survey of 60 random members of the public to attempt to gauge how willing they would be to give our night-light to a child, and to ascertain their overall view of genetically modified organisms. A full list of the questions asked can be seen here.

In particular, we were looking at:

• The demand for a children’s product in this genre
• The respondents’ level of science education
• How strongly people agreed or disagreed with 7 points:
  1. I would allow my child to have an educational toy that needed to be fed and looked after once a day with my supervision.
  2. I would allow my child to have an educational toy that incorporates E.coli bacteria.
  3. I would allow my child to have an educational toy that incorporates genetically modified bacteria.
  4. I would allow my child to have an educational toy that incorporates bacteria.
  5. All strains of E.coli are dangerous.
  6. E.coli regularly exists in my body.
  7. If these genetically modified bacteria were accidentally swallowed by someone, they would become dangerously ill.

For the 7 opinion points, we first assessed how they felt about them as it stood in that moment with their current level of knowledge on the subject, then allowed them to read more information about the bacteria we were using in our project:

What is 'synthetic biology'?
Synthetic biology is a branch of biology that combines the powers of biotechnology, evolutionary biology, molecular biology, systems biology, biophysics, computer engineering, and genetic engineering (to name but a few) in order to construct 'biological devices' or 'machines' that are useful for solving problems - anything from something as trivial as chewing gum on the streets to solving climate change.

What are e.coli?
E.coli bacteria are commonly found in the lower intestine of warm-blooded organisms (in other words, you and I!) where they make up the normal flora of the gut, produce vitamin K2, and prevent dangerous bacteria from growing. Most strains of e.coli are completely harmless, however there are one or two types that cause serious food poisoning - because of this, many people understandably assume that just because it's called 'e.coli', it must be very harmful, however this isn't the case! In our labs, classes and research, we use e.coli as they grow quickly and are easy to look after. The bacteria we use are a 'lab strain' which means we know exactly what their genotype is (the full set of genes present in the organism), and any and all dangerous genes or features that could cause it to infect humans and cause illness have been removed.

What are you doing to it?
Over the summer we have been working on taking bioluminescence genes out of a bacterium called Aliivibrio fischeri and genes from a cyanobacterium called Synechocystis that can detect UV-A light from the sun, and placing them in our e.coli cells. When combined with some other standard genetic parts, the result is e.coli bacteria that glow when it's dark!

What are you using it for?
Our project involves designing a toy nightlight for children based around the idea of a "friendly monster", i.e. one that scares away the bad monsters under the bed! This would involve a stuffed monster toy, inside which would be a clear plastic container that would hold our bacteria. Every morning the child, with parental supervision, would turn a tap at the base of the toy, and the nutrient solution containing the bacteria would drop out of the bottom into the toilet to be flushed away. The handle of the tap connects via a key slot so that curious children can't open it and spill everything everywhere on their own. The child can then "feed" their monster friend by pouring fresh nutrient solution into their mouth, which passes through a tube through a one-way valve down into the main part of the vessel, so that if it were dropped or accidentally turned upside down the bacteria and solution would stay inside. There would be enough bacterial residue stuck to the inside of the container to allow them to repopulate during the day while the child is at school or nursery. Once they no longer detect the UV-A from the sun, the bioluminescence system becomes activated and they will begin to glow. At night the child would give the monster a gentle shake, which would allow oxygen to distribute more evenly among the bacteria encouraging brighter, more even bioluminescence.

Kids are mischievous and curious, what if they tried to eat it?
The bacteria are harmless, as is the nutrient solution they'd be in. The environment in the stomach would kill them immediately. However, it wouldn't taste very nice at all, which may cause them to bring it back up. Ultimately the child would come to no lasting harm and would not require professional medical treatment, just a big glass of water to get rid of the taste.

The same questions were then asked again, in order to see if providing more information about the details of our project would alter the public’s view on these points.

The results here show that, although there are perceived gaps in the market for toys that fill any of the demonstrated criteria, there is significantly more demand for 'scientific' toys - because of this we moved the focus of our design more towards being an educational tool, rather than the other two objectives.

1ml 10x serial dilutions were made up to 10-6 from a 5ml overnight of each strain. 10µl spots of each dilution were then spotted onto LB agar plates. These plates were then exposed to 50µmoles/m2/s of UVA at room temperature in illumination cabinets. Time points were then taken by removing plates from the illumination cabinet.
After illumination, plates were incubated at 37°C, under the assumption that every single viable cell will form a colony. The length of incubation is irrelevant, provided that every cell is given enough time to form a visible colony. This also forms the basis of our counting system, where a colony is assumed to have come from a single cell. We also make the assumption that cell division at the temperature and time we were running the experiment was negligible/nonexistent.
After incubation, the colonies on each spot/dilution were counted. The number of colonies from the lowest visible dilution (some dilutions formed a lawn of growth) were then multiplied by the dilution factor to approximate how many cells would be in 10µl of undiluted culture.

We seemed to be seeing a decrease by 30 mins and between 60 and 120 at least in the recA positive strains the decrease between 0-30 is much steeper in the reca negative strains (fig1).
Since we had no time points between 60 -120 we decided to take time points at 80 100 120 to better visualise the change (fig 2).


As noted above figure 2 show this second decline seems to be a feature of MG6115 and DS941, may be du e to their recA status


It’s reported that E.coli suffer lethal effects at around 1000kw with illumination at 366nminin continuous culture (Berney et al 2006).this corresponds with around 16 hour with the fluence and wavelength we were using. We decide to illuminate bacteria for 14hours as we felt that if least some bacteria could withstand 14 hours of activating radiation then the idea as using UVA as the input into the toy was at least theoretically feasible

Plates at 14 hours showed growth