Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

First Advisor

Carl Westby


Cheese whey is a by-product of the dairy industry and contains approximately 5% lactose, 0. 9% nitrogenous compounds, and small amounts of vitamins and minerals. It has often been treated as waste. In addition to the loss of these nutrients, its disposal creates pollution problems. Lactose which is the chief nutrient in whey, could be more profitably utilized by being converted into ethanol. Unfortunately, naturally occurring strains of brewer’s yeast (Saccharomyces cerevisiae) are unable to metabolize lactose and hence cannot convert it to ethanol. The overall objectives of my study were: 1.) To construct a S. cerevisiae - Escherichia coli shuttle plasmid (pBW314) carrying the lacZ gene for lactose metabolism and the kanamycin resistance (kanr) gene for resistance to G418. 2.) By selecting for resistance to G418 to isolate laboratory and fuel alcohol (Y45 and Y6) strains of S. cerevisiae transformed by this plasmid. 3.) To test one of the transformed strains (Y45 with pBW314) for ethanol production from lactose.

Library of Congress Subject Headings

Alcohol as fuel
Escherichia coli



Number of Pages



South Dakota State University


No Copyright - United State