Publication Date

2022

Document Type

Dissertation/Thesis

First Advisor

Swingley, Wesley D.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences

Abstract

Oxygenic photosynthesis is one of the primary metabolisms on Earth responsible for the evolution of complex life. Its advent around the Archean steadily increased Earth’s atmospheric oxygen from negligible amounts to biologically impressive quantities. Atmospheric oxygen is the sole result of billions of years of biological oxygenation and no abiotic process can account for its high presence in the Earth’s atmosphere. Understanding its origins and evolution can lead us to better understand Earth’s biological history and the possibility of analogues elsewhere. A research path that could lead to answers is comparing distinct incorporations of photopigments in various oxygenic phototrophs. In this study, I sought to characterize and quantify oxygen production under far-red and white light conditions for two closely related cyanobacterial species to better understand photopigment integration and the evolution of biogenic oxygen. Characterization and quantification were performed by recreating two distinct light treatments that supplemented light capturing adaptations. Strains were cultured and then subjected to distinct light treatments where oxygen production was measured across a time series resulting in average oxygen production rates as a proxy for photosynthetic activity dependent on pigment incorporation. Acaryochloris marina MBIC 11017 and Acaryochloris thomasi RCC1774 were the studied cyanobacterial strains containing Chl d and Chl a as primary photopigments respectively. The main focus of this study is to evaluate the differences in oxygen production as a result of primary photopigment incorporation. Additional questions address why this difference exist and what it implies on the overall origin and evolution of photosynthesis. Future work should compare additional far-red pigments oxygen production to expand our understanding of biosignatures and the evolution of life.

Extent

65 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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