Content - some data, some of the discussions/outreach we had with people.
credit Ashley and Mike for assisting in sample collection.
Caffeinated Coli
Jordan discussing our project with a coffee shop employee at Flat Track Coffee
In 2014, the UT Austin iGEM team was asked to create a presentation for the South By Southwest Create event. There were many relatively new team members, so the team saw the opportunity to not only teach new members essential research techniques, but also saw this as a wonderful opportunity to reach out to the community and raise awareness for the emerging field of synthetic biology. The team decided to revive an old iGEM project, the "Caffeinated coli," to measure the caffeine content of various different brands and types of coffee. The group split up and visited dozens of local Austin coffee shops, collecting samples of their house coffee. We were met with much enthusiasm by the coffee shop owners, who's interest had been peaked when we described our experiment. The samples were taken back to lab, and using a strain of E. coli previously developed by the 2012 UT Austin iGEM, we employed these E. coli to assess how much caffeine was present in each cup of coffee.
Ella collecting coffee sample from Austin Java
Figure 1. Relative levels of caffeine in house coffee samples from around Austin.
[http://www.google.com/maps/d/viewer?mid=zlUDhks6KHxI.ketDvlvg6zis Click here for an interactive map of coffee shops we visited!]
A couple of weeks later, we presented this data set at the 2014 South by Southwest (SXSW) festival as part of the SXSW Create section, which focuses on the maker/hacker/DIY culture. As part of this outreach, we explained our project and synthetic biology to a wide range of people (Figure 3). Many people who came by had little to no background in science or technology, and even most of the ones who did had not heard about synthetic biology. By discussing our experiments with bacteria and coffee, an interesting and easy to understand application, we were able to explain what synthetic biology is and how it can be used in a beneficial way. Occasionally, these conversations would branch out into wider topics of science and technology.
change to picture of team member presenting poster at event
This included a follow up conversation with one of the owners of Wright Bros. Brew & Brew, whose coffee seemed to have significantly more caffeine. The owners concluded, after discussing our project and the coffee brewing process, that the specific pot of coffee was probably just not fully drained, i.e. there was less water in the batch than normal, resulting in a higher caffeine/volume content. However, similar conversations were had between the entire team and the various coffee shops and baristas during the collection and presentation processes.
Measuring Caffeine Content
Standard growth curve of knockout strain grown with different amounts of caffeine.
Cultures of knockout strain grown with collected coffee samples.
The E. coli we used are a synthetic strain, previously made by the 2012 UT Austin iGEM team. This strain lacks [...its normal guanine synthesis pathway], but contains a plasmid with a set of genes that enables the organism to synthesize guanine from xanthine and many of its derivatives, including caffeine. Without caffeine (or other xanthines), the strain cannot grow. When caffeine is added, the strain grows normally until the caffeine is completely metabolized, at which point the cells can no longer synthesize guanine, and cease to grow. Thus, by looking at the relative growth of the strain with different samples of coffee and comparing it to a standard curve of growth in solutions with known amounts of caffeine, we could somewhat accurately measure the amount of caffeine in the coffee.
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