Name: ____________________________________ Partner: ___________________________________

Optimizing Yeast Fermentation

Introduction

If you have ever walked by a small local bakery, you might wonder how the baker is able to compete with the name brand companies. Here is your chance to find out how they do it.

Your fermentation design team has been contacted by a local bakery that wants to speed up their bread production in order to increase sales. They need to optimize fermentation of available baker’s yeast. They aren’t interested in how much alcohol they are producing but are very concerned about the amount of CO2 released over time. The goal of this activity is to engineer the optimal conditions for the mass production of yeast fermentation.

This is very similar to what would occur in biopharma companies. A variety of conditions would be tested by biopharma companies to determine the most effective physical and chemical parameters for scale-up in a bioreactor.

Why is this important? In biotechnology research and industry, transformation is just the first step in producing a genetically-engineered protein. The second step after the research and development of a new biopharma system is scale-up mode. In this phase the organism must be grown in large quantities in preparation for final production.

A critical phase in the scale-up of a bioreactor for a process engineer is the optimization of environment. Many variables in bioprocesing must be understood and tested to completely optimize production or performance of yeast fermentation

Equipment


· Your respirometer

· Engineering Notebook

· Yeast (brewers)

· Substrates:

§ Cane Sugar (Sucrose)

§ Lactose & Glucose


Procedure

You and your partner must characterize optimal conditions for yeast fermentation. You will be able to manipulate the type and amount of the substrate (sucrose, lactose or glucose). Your lab should be based on design principles from Fermentation Instrumentation.

Considerations for you to create optimal conditions:

· Substrate (Sucrose, Lactose, Glucose)

· Amount of Yeast (brewers)

Test at least six different conditions using the variables above with replication (n>2) for each treatment. Be sure to have a control group for each treatment. Document the conditions and results of the yeast optimization study in your engineering notebook.

Using the appropriate statistics, demonstrate which condition is optimal and explain how the statistics prove the optimization of the yeast fermentation.

Using your engineering notebook, document the entire optimization study.

Conclusion

1. What is a bioreactor?

2. What is a chemostat?

3. What are some of the applications of alcoholic fermentation in modern biotechnology?

4. What was the role of the different control groups in the experimental process?

5. What is the advantage of a bioreactor compared to organic synthesis for a product?

6. How can the optimization process used in this activity lead to new approaches in renewable energy?