Undergraduate Research: An Archive - 2021 Program

Rebecca Mays ’21
CHEMICAL AND BIOLOGICAL ENGINEERING
Certificate in Environmental Studies
THESIS TITLE
Optogenetic Control of
Microbial Consortia for
the Optimization of
Chemical Production
ADVISER
José Avalos, Assistant
Professor of Chemical
and Biological
Engineering and the
Andlinger Center for
Energy and the
Environment
Metabolic engineering modifies genetic
pathways in microbes to more efficiently produce
chemical compounds. However, engineered
pathways induce metabolic burden within
microbes. Microbial consortia divide metabolic
labor among several microbial strains but
require control systems to ensure microbes
in consortia operate at ratios to maximize
production. My research built on previous work
that tuned microbial growth using blue lightactivated
genetic circuits. Optogenetic control
provided dynamic control over consortia of
Saccharomyces cerevisiae and optogenetically
controlled Escherichia coli, which produced
isobutyl acetate — a valuable industrial chemical
— and naringenin, a valuable pharmaceutical
compound. We then explored media containing
lignin-derived acids with naringenin-producing
S. cerevisiae. Lignin is a waste byproduct of many
chemical processes, the valorization of which
has economic and environmental implications.
We characterized the toxicity of several
acids to S. cerevisiae before examining the
detoxifying effects of optogenetically controlled
Pseudomonas putida in consortia with S.
cerevisiae. This research demonstrated the more
sustainable production of valuable chemical
compounds.
ENVIRONMENTAL
ENGINEERING
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