Harnessing the Power of Mutagenesis and Adaptive Laboratory Evolution for High Lipid Production by Oleaginous Microalgae and Yeasts

TLDR

Oleaginous microalgae and yeasts are promising for large‑scale lipid production for biofuels, nutraceuticals, pigments, and cosmetics, yet low productivity and costly downstream processing limit their commercial deployment. The study aims to review random mutagenesis and adaptive laboratory evolution as strain‑improvement strategies to increase lipid yield and reduce production costs. It surveys mutagenesis and ALE techniques and screening methods that select for high‑lipid microalgae and yeasts and elucidate metabolic pathway changes to inform future genetic engineering.

Abstract

Oleaginous microalgae and yeasts represent promising candidates for large-scale production of lipids, which can be utilized for production of drop-in biofuels, nutraceuticals, pigments, and cosmetics. However, low lipid productivity and costly downstream processing continue to hamper the commercial deployment of oleaginous microorganisms. Strain improvement can play an essential role in the development of such industrial microorganisms by increasing lipid production and hence reducing production costs. The main means of strain improvement are random mutagenesis, adaptive laboratory evolution (ALE), and rational genetic engineering. Among these, random mutagenesis and ALE are straight forward, low-cost, and do not require thorough knowledge of the microorganism’s genetic composition. This paper reviews available mutagenesis and ALE techniques and screening methods to effectively select for oleaginous microalgae and yeasts with enhanced lipid yield and understand the alterations caused to metabolic pathways, which could subsequently serve as the basis for further targeted genetic engineering.