Manganese Through Time and Other Stories Concerning Cyanobacteria and the World Around Them

Author: Lingappa, Usha Farey

Year: 2021

Degree: Dissertation (Ph.D.)

Advisor: Fischer, Woodward W.

Committee Members: Orphan, Victoria J.; Grotzinger, John P.; Newman, Dianne K.; Fischer, Woodward W.

Option: Geobiology

DOI: 10.7907/9ysw-jt52

Abstract

This thesis is a collection of investigations concerning the interplay between Cyanobacteria and the inorganic/physical world. Chapters II-VI focus on manganese, an element Cyanobacteria have been intimately entangled with for billions of years. Chapter II is a review/perspective paper on the dynamics of manganese in the environment through time and the many ways manganese interfaces with dioxygen. Chapter III deciphers environmental and biological signatures recorded in ancient rocks from the pivotal moment in Earth history when oxygenic photosynthesis first evolved. Chapter IV explores the ecology of desert varnish, and provides an adaptive physiological mechanism underpinning manganese enrichment. Chapter V examines the ability of modern Cyanobacteria to catalyze manganese oxidation. Chapter VI explains as kindly as possible that the field of manganese aquatic chemistry has fundamentally misunderstood the chemistry of Mn(III) and highlights how the current methods being used are problematic because of this misunderstanding. Chapters VII and VIII are not about manganese and instead concern other aspects of the physical world and their interface with Cyanobacteria. Chapter VII is about the impact of Hurricane Irma on a cyanobacterial mat ecosystem. Chapter VIII is about the use of ooids as an environmentally friendly replacement for plastic microbeads in facial scrubs, in which Cyanobacteria make a cameo as endoliths that facilitate ooid dissolution.

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