Rather than follow the lesson plans for Lessons 34 and 35, we decided to skip the butyric acid lab and instead grow biofabric using Suzanne Lee’s kombucha tea recipe. We watched her TED Talk and then students had the opportunity to read the Popular Science article detailing how to prepare the tea (both available on a previous Biology class post from September 4 this year). Students were also provided with the label from a bottle of store-bought kombucha pictured below:
Plan for December 10:
- Working in a group of 3-4 students:
- Prepare the kombucha biofabric growth medium. Following the recipe in the article, brew the green tea and add sugar sugar. Cover with a cloth and allow to cool overnight.
- Write a procedure for brewing kombucha tea for the sole purpose of producing bacterially-derived cellulose (the scoby). Document the steps in a research report.
- Research how the bacterial strains known to be present in the store-bought kombucha (Bacillus coagulans GBI-30 6086 and Saccharomyces boulardii) metabolize the growth medium to produce cellulose. Document sources and include findings in the report.
- Research the chemical formula and structure of cellulose. Identify the individual subunits of cellulose and explain how the subunits combine to form the cellulose polymer. Document sources and include images in the report as appropriate.
- Explain how cellulose might be modified to make it waterproof (hydrophobic). Create a molecular model of your idea and take a picture of the molecule to include in the report.
Plan for December 11:
- Add apple cider vinegar and kombucha bacterial culture to growth medium and include a piece of scobe. Cover with a cloth and incubate with periodic observation over several weeks.
- Continue working on the research report from the previous day.
Kombucha Tea Review (scientifically credible):