Photoautotrophic growth of eukaryotic microalgae and electron detours under deficient sink stress

Abstract

Eukaryotic microalgae have been an attractive target for use in the bioeconomy for over 70 years because of their ability to efficiently generate biomass from CO2, sunlight, seawater, and fertilizer. In this thesis, I will demonstrate the isolation of a promising new industrial alga, Picochlorum celeri, which has one of the highest maximum growth rates ever reported. The organism’s hallmark is a high chlorophyll concentration, a dynamic antenna regulated by light, and a high net oxygen evolution rate. In addition to this new biotechnology strain, a starchless mutant of the model organism, Chlamydomonas reinhardtii, was photosynthetically characterized which unmasked water-water cycles cause by uncoupled light reactions and carbon metabolism. In this analysis, the apparent maximal rate of Flavodiiron proteins was calculated as they activate under light transitions as well as the usage of the Plastid terminal oxidase under both inactive carbon metabolic stress and nitrogen deficiency.