University of Iowa Honors Theses

Major Department

Chemistry

College

College of Liberal Arts & Sciences

Degree

BS (Bachelor of Science)

Session and Year of Graduation

Spring 2018

Honors Major Advisor

Claudio J. Margulis

Thesis Mentor

Shuvendu Das, Mark A. Arnold

Abstract

Myceliophthora thermophila can produce various cellulolytic enzymes that degrade the major polysaccharides of plant biomass. Cellulase (exoglucanase) is an enzyme produced by these cells and excreted in the supernatant of the culture broth during fermentation processes. Different temperatures were investigated as a means to increase production yield of the cellulase activity during seven days of fermentation. The highest yield was observed for the temperature range of 45-48 ˚C. The highest enzyme activity was 24.3 ± 0.2 U/mL of supernatant, which was observed during the culture growth at 45 ˚C. The enzyme activity decreased slightly at 48 ˚C to 21.5 ± 0.2 U/mL of supernatant. At 32 ˚C, 38 ˚C, and 41 ˚C, the enzyme activity decreased by nearly 50% (12.4-13.1 U/mL) in comparison to yields at 45 ˚C and 48 ˚C. For these measurements, one unit of enzyme activity is defined as the amount of enzyme releasing 1 μmol of p-nitrophenol per minute at pH 5.0 and 50 ˚C. In addition, the uncommon buff color of culture and branched hyphal cells were observed in 45 ˚C and 48 ˚C fermentation flasks.

Keywords

Myceliophthora thermophila, fermentation, cellulase, exo-cellobiohydrolase, enzyme activity, temperature optimization

Total Pages

20

Copyright

Copyright © 2018 Daning Lu

Included in

Biochemistry Commons

COinS
 

URL

https://ir.uiowa.edu/honors_theses/152