With more than two dozen companies in Pennsylvania manufacturing potato chips, it is no wonder that researchers in Penn State's College of Agricultural Sciences have developed a novel approach to more efficiently convert potato waste into ethanol. This process may lead to reduced production costs for biofuel in the future and add extra value for chip makers.
With more than two dozen companies in Pennsylvania manufacturing potato chips, it is no wonder that researchers in Penn State's College of Agricultural Sciences have developed a novel approach to more efficiently convert potato waste into ethanol. This process may lead to reduced production costs for biofuel in the future and add extra value for chip makers.
Using potato mash made from the peelings and potato residuals from a Pennsylvania food-processor, researchers triggered simultaneous saccharification — the process of breaking down the complex carbohydrate starch into simple sugars — and fermentation — the process in which sugars are converted to ethanol by yeasts or other microorganisms in bioreactors.
The simultaneous nature of the process was innovative, according to researcher Ali Demirci, professor of agricultural and biological engineering. The addition to the bioreactor of mold and yeast — Aspergillus niger and Saccharomyces cerevisiae, respectively — catalyzed the conversion of potato waste to bioethanol.
The bioreactor had plastic composite supports to encourage and enhance biofilm formation and to increase the microbial population. Biofilms are a natural way of immobilizing microbial cells on a solid support material. In a biofilm environment, microbial cells are abundant and more resistant to environmental stress causing higher productivities. In this application, these benefits were especially important because mold enzyme activity required higher temperature and the yeast had to tolerate this.
Read more at Penn State
Image: Researcher Ali Demirci adjusts a bioreactor in which potato waste is being used to produce bioethanol with a novel process that simultaneously employs mold and yeast to convert starch to sugar and sugar to ethanol. (Credit: Dimerci Lab)
