Where Bio Inks gets its color
The hardest workers at The Tech? Look no farther than Bio Inks, where pigment-making bacteria are dividing 24/7
If you’ve visited The Tech’s BioDesign Studio in the past few months and participated in our Bio Inks experience, you’ve had a chance to make art using ink created with the help of real, living bacteria. The pigment that gives beautiful color to our ink is a byproduct of the natural bacteria Streptomyces violaceoruber as it multiples. Every visitor to Bio Inks helps extract the pigment, but they’ve never actually gotten a chance to meet the microscopic organisms that supply the exhibit with its art supplies.
Until now.
Allow Anja Scholze—experience developer and program manager, biotech & health—to introduce you to the hardest workers at The Tech, who are producing pigments all day, every day.
Check out each step along the path that takes these pigments from the petri dish to your paintbrush.
Step 1: The vial where it all starts
The bacteria used in Bio Inks originates from a vial kept at freezing temperatures to preserve the sample.
Step 2: The bacteria begin to grow
The bacteria is swabbed over filter paper placed on agar in a petri dish. Agar is a jelly-like substance that provides food for the bacteria and collects the pigment byproduct as the bacteria grow.
This picture shows an example of a young sample. The reddish colonies of bacteria have not begun to release pigment yet, but as they mature, the colonies will turn white and begin to color the agar. Notice how the agar beneath the white colonies is already changing color to blue!
Step 3: A petri dish pigment farm
After the bacteria have matured and covered the filter paper, the agar should be fully blue. You can even see droplets of pigment on the surface of the bacteria!
Step 4: Transferring the bacteria culture to fresh agar and keeping the pigment
Once the agar is saturated with pigment, it’s time for the bacteria to get to work on a fresh dish. But we have to be careful, we only want to grow Streptomyces violaceoruber and not any other types of bacteria.
Whenever the petri dish is open , it has to be in a sterile environment, like the laminar flow hood behind the scenes in BioDesign Studio. The air around us has lots of organisms that would love to make a petri dish with fresh agar their home, so we have to keep them out. The laminar flow hood accomplishes this with a constant stream of filtered air blowing unwanted particles away from the dishes.
Inside the laminar flow hood, staff members work with tools that have been sterilized inside an autoclave — a pressure cooker-like device that uses high temperature steam to kill bacteria and other unwanted organisms — to handle the samples. They carefully move the filter paper that is home to a thriving neighborhood of pigment producers to a dish with fresh agar, while the blue agar is ready to be used by visitors in our Bio Inks workshop.
Step 5: The pigment enters the BioTinkering Lab
The agar, minus the bacteria, now goes to the BioTinkering Lab. Here, staff members prepare it to be used in the Bio Inks activity by dividing it into smaller parts.
Step 6: The Tech’s visitors harvest the pigment
Bio Inks begins! Our visitors join the bioengineering process at this point to help us separate the precious pigment from the agar using a selection of scientific and household tools of their choosing. Once test tubes are full of extracted pigment solution, the unique pH-sensitivity of the pigment means visitors can play with chemistry to alter its color, by adding acids (like lemon juice) or bases (such as laundry detergent) to their sample. This results in hues of pink, purple and blue, letting visitors choose their favorite colors to contribute to our collection flasks.
Step 7: The pigment goes to the drying station
There’s one last step before the ink is ready to be made into art. The different colored pigment solutions from Bio Inks are sent to a drying station to further concentrate the pigment.
Last stop: Our visitors make art
After it dries, the pigment returns to Bio Inks. Visitors draw, write and stamp with the pigment to produce organic art. Currently, there are very few places in the world using this type of pigment; Scholze knows of a startup in France that is working to commercialize pigment production in Streptomyces strains, as well as an artist who uses it to dye fabric. But it makes you think, one day, could Streptomyces violaceoruber help us produce the art supplies you find in stores or the ink in your printer?
“Using pigment produced by bacteria is an exciting use of biology that may or may not be used at a large scale in the future,” Scholze says. “Bio Inks is a really good reminder to our visitors that science isn’t static facts, it’s a process and part of the fun of science is discovery.”
But that’s not all! We’re still cooking up new uses for the pigment.
Some of the pigment our visitors harvest is kept behind the scenes in our support lab where staff uses it for novel testing and experimentation. For example, we are currently prototyping different recipes to make our unique bio ink dry faster and flow smoother, as well as a way to use the pigment to create real watercolor paints. Based on the results from these experiments, we will change and improve the activity. So, visitors to Bio Inks get to see and contribute to the discovery process!
This exhibit was made possible by a Science Education Partnership Award (SEPA), Grant Number R25 GM129220, from the National Institutes of Health (NIH). Has Bio Inks grown on you? Learn more about BioDesign Studio or plan your next visit to The Tech.
