Engineering of Corynebacterium glutamicum For the Secretion of Lignin-modifying Enzymes
Description
Lignin is a naturally abundant source of aromatic carbon but is largely underutilized inindustry because it is difficult to decompose. Recent research activity has targeted the
development of a biological platform for the conversion of lignin and lignin-derived
feedstock. Corynebacterium glutamicum is a standout candidate for the bacterial
depolymerization and assimilation of lignin because of its performance as an industrial
producer of amino acids, resistance to aromatic compounds in lignin, and low
extracellular protease activity. Under the current study, nine experimental strains of C.
glutamicum were engineered with sequencing-confirmed plasmids to overexpress and
secrete lignin-modifying enzymes with the eventual goal of using lignin as raw feed for
the sustainable production of valuable chemicals. Within the study, laccase and
peroxidase activity were discovered to be decreased in C. glutamicum culture media. For
laccase the decrease reached statistical significance, with an activity of about 10.9 U/L
observed in water but only about 7.56 U/L and 7.42 U/L in fresh and spent BHI media,
respectively, despite the same amounts of enzyme being added. Hypothesized reasons for
this inhibitory effect are discussed here, but further work is needed to identify causative
factors and realize the potential of C. glutamicum for waste biomass valorization.
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2022
Agent
- Author (aut): Ellis, Dylan Scott
- Thesis advisor (ths): Varman, Arul M
- Committee member: Lammers, Peter J
- Committee member: Long, Timothy E
- Publisher (pbl): Arizona State University