Yeast Raises the Biomass Bar
Researcher explores the optimal conditions for growing yeast as a renewable energy source
Microbes such as Yarrowia lipolytica, depicted, can be genetically engineered to generate significant amounts of lipids from carbohydrates. The can then be used to produce gasoline, diesel, jet fuels, and other bio-based chemicals.
Yeast—the same ingredient used to make bread—is the single cell microorganism that powers the biomass industry. Manufacturers fatten up the yeast cells by feeding them sugars that are derived from plants and other feedstock. They then harvest the resulting lipids, or fat, to produce gasoline, diesel, jet fuels, and other bio-based chemicals. The faster the yeast cultivates, the bigger the cells get, and the more lipids manufacturers can collect.
Over the last 10 years, Pacific Northwest National Laboratory (PNNL) has practically written the book on the process, and now PNNL researcher Jim Collett is busy adding another chapter. Collett is exploring the optimal conditions to grow lipid-rich yeast and how to automatically measure the growing environment within bioreactors.
Optimal growing conditions vary according to the feedstock. However, too often manufacturers use the same conditions for different feedstock, limiting lipid production. Likewise, manufacturers typically test bioreactor conditions using a manual sampling process. This slows down production and limits their ability to quickly adjust and reach prime growing environments.
Collett's goal is to produce a guide for bio manufacturers to follow, as well as monitoring technologies that can be used to create an adaptive control system that would measure growing conditions in real-time. Biomass manufacturers would then be able to adjust conditions more quickly, resulting in higher yields and ultimately increasing the availability of this renewable energy resource.