Early Cyanobacteria and the Innovation of Microbial Sunscreens.

Patrick M Shih

doi:10.1128/mbio.01262-19

Abstract

Metabolism drives life; thus, understanding how and when various branches of metabolism evolved provides a critical piece to understanding how life has integrated itself into the geochemical cycles of our planet over billions of years. Although the most transformative metabolisms that have significantly altered the trajectory of Earth are inherently linked to primary metabolism, natural products that stem from specialized metabolic pathways are also key components to many auxiliary facets of life. Cyanobacteria are primarily known as the original inventors of oxygenic photosynthesis, using sunlight to split water to create our dioxygen-filled atmosphere; however, many of them also have evolved to produce small molecules that function as sunscreens to protect themselves from ultraviolet radiation. Determining when cyanobacteria first evolved the ability to biosynthesize such compounds is an important piece to understanding the rise of oxygen and the eventual success of the phylum.

Highlights

Metabolism drives life; understanding how and when various branches of metabolism evolved provides a critical piece to understanding how life has integrated itself into the geochemical cycles of our planet over billions of years
It is widely accepted that this is due to the biological innovation of oxygenic photosynthesis in ancient cyanobacteria, and a significant body of work has focused on constraining the timing of this monumental evolutionary innovation [1,2,3]
Much emphasis has been devoted to studying the events leading up to the evolution of oxygenic photosynthesis, the subsequent accumulation of dioxygen dramatically broadened the scope of metabolism for life as a whole

Summary

Introduction

Metabolism drives life; understanding how and when various branches of metabolism evolved provides a critical piece to understanding how life has integrated itself into the geochemical cycles of our planet over billions of years. Garcia-Pichel et al expand upon previous genetic/genomic work on elucidating the sunscreen biosynthetic gene cluster of scytonemin, a widespread cyanobacterial sunscreen, with molecular clock analyses to help constrain the timing of the cyanobacterial phylum and the evolution of scytonemin biosynthesis [6].

Results

Conclusion