Week Five: Life at different scales I
Fall 2015 | Mónica Butler | Second Year Integrated Product Design
This week we explored the implications of biological design at different scales. Part One of this series took on the discussion of designing with life at the macro scale, and its implications in culture, making emphasis on the study and applications of Biofilms and Microbial Fuel Cells (MFC).
Lecture: EXPLORING THE CULTURAL IMPLICATIONS OF BIOFILMS
Analogous to a city of microbes, as Paula Watnick and Roberto Kolter describe it, biofilms are structures that associate to surfaces made by an amalgamation of diverse species of microbes, packed tightly together. These microbial communities are dynamic, and show a set of characteristics particular to their behavior as a group of diverse cells. For instance, they move, come and go as they need to, they share genetic material in the form of plasmids among each other, and through an exchange of quorum sensing molecules they are able to communicate with each other. This communication enables them to perform gene regulation as a way to react to the environment in which they have adhered, in order to maximize their survival.
It is important to note a distinction between naturally occurring biofilms and designed biofilms. As we have noted in the past, biological design implies manipulating life, driven by intention, this is no different when talking about biofilms. Although in natural environments, biofilms are almost invariably a multispecies microbial community, like the regular plaque that builds up in our teeth, whereas in an intentional design, biofilms can be created with a selection of microbes or a selection of genetically modified microbes so they perform as intended by a designer. Such is the case of the hypothetically designed CMYK Plaque by Daisy Ginsberg, in which she uses engineered E. Coli to create colored biofilms in teeth that express evidence of plaque buildup, in a loud fashion. This informs us about new cultural implications of biofilms: If we can select specific organisms to interact with each other the way biofilms do, we can trigger intended interactions in unprecedented contexts.
BIOFILMS AS A MEDIUM OF EXPRESSION
Innovative creators and thinkers alike generate pieces of work that invite us to speculate about how new technologies can be implemented. To serve as inspiration to guide our final projects, in class we looked at the work of different artworks and products, that invited us to think about biofilms in new ways.
Biofilms as a critique medium: We observed the work of Kara Walker, an African American artist, who explores race, gender, sexuality, violence and identity in her artworks. She constantly uses imagery pertaining to the classical era to illustrate images of the African American history. Utilizing the contrast of both to serve as a critique medium, and an invitation to discussion about the use of art to depict history and identity. In what ways we can use the nature of biofilms as a medium for critique?
Biofilms as consumer products: Bacteria are constantly associated with negative connotations. It seems like our modern culture is looking to remove or annihilate bacteria from every scenario, when in reality, our bodies contain multitudes of bacterial species naturally. A cosmetic product line called Mother Dirt, calls for the opposite: to embrace the natural microbiomes of our skin. How can we utilize biofilms to radicalize the ways we consume?
Biofilms to create new material statements: Using bacteria to assist in the creation of cellulose from fermented liquid of tea and live kombucha culture, new fabric-like materials are now being used like the ones created by BIOCOUTURE in the UK. This recipe is under a creative commons license, and invites us to think about new opportunities to create or modify existing materials. Another example is mycelium, whose structural qualities have been used in the past to create new building materials. What new sustainable materials, can we create by incorporating designed biofilms? What new relationships can we explore between biology and material science?
Biofilms as power sources: Microbial Fuel Cells, are systems designed to utilize electrogenic bacteria, such as Geobacter, to generate electrical current. These bacteria are anaerobic by nature and are capable of moving electrons from organic materials found in their environment to conductive surfaces through their metabolism. How can we harness the electrical power provided by Geobacter biofilms to rethink our relationship with energy?
Lab: Transformation & Microbial Fuel Cells
That last bit we took to our lab on Wednesday for further exploration, but before we did, we took a moment to complete the last part of the Violacein Factory lab: Transformation.
Cultures of thriving competent E. Coli were provided to us so we could proceed to add our designed DNA plasmids to their cells. In order to do so, Prof. Hogan explained us the behavior of the plasmids and the cellular membranes of E. Coli. Soon we understood that via a well-regulated heat shock, we would be able to incorporate our DNA designs into competent E. Coli, and hopefully have them generate Violacein following the metabolic pathways we designed.
- Stage #1: Heat shock the culture of bacteria, so the plasmids containing the DNA designed on the previous lab penetrate into their cells. These plasmids contain resistance to the chloramphenicol antibiotic.
- Stage #2: Give them food! The bacteria is transferred to a petri dish that has an agar mix containing L-Tryptophan and the antibiotic, so every cell that didn't acquire the designed plasmid, dies.
- Stage #3: Store and let them grow! We'll eventually be able to see if our designs turned out to express Violacein, after metabolizing L-tryptophan.
After we finished the transformation, we had a chance to create our own microbial fuel cells (MFCs) (and play with mud). We used the Mudwatt kit from Keegotech to create a simple Microbial Fuel Cell, utilizing the electrogenic that live in regular potting soil mix. The Mudwatt kit provides a container that serves as closed system for our bacteria to grow, and two carbon fiber screens that are connected to wires. These wires go all the way out of the container so we can eventually connect it to a circuit, one to be used for positive and the other to connect to ground. The screens, will provide the surface needed for the bacteria to get attached and create a biofilm. This simple kit requires only to add mud and give it some time to grow, to be able to use. In optimal conditions, it is capable of generating up to 0.8V. The plan is to explore creating electrical circuits using our MFCs connected to a capacitor as a power source.
During lab next week we'll be using voltmeters to verify how well our MFCs performed, a true indicator of how well that specific biofilm has developed over time.