Strain Development in Microalgal Biotechnology—Random Mutagenesis Techniques

Abstract

Microalgal biomass and metabolites can be used as a renewable source of nutrition, pharmaceuticals and energy to maintain or improve the quality of human life. Microalgae’s high volumetric productivity and low impact on the environment make them a promising raw material in terms of both ecology and economics. To optimize biotechnological processes with microalgae, improving the productivity and robustness of the cell factories is a major step towards economically viable bioprocesses. This review provides an overview of random mutagenesis techniques that are applied to microalgal cell factories, with a particular focus on physical and chemical mutagens, mutagenesis conditions and mutant characteristics.

Enhancing algal production strategies: strain selection, AI-informed cultivation, and mutagenesis

“…The process of random mutagenesis involves subjecting microalgae cells to chemical or physical mutagens, leading to the generation of a diverse population of mutants with distinct genetic and phenotypic characteristics (Fathy et al, 2023). Examples of chemical mutagens are alkylating agents, Base Analogs (BAs), AntiMetabolites (AMs), and Intercalating Agents (IAs) while the physical mutagens include UV radiation, ionizing radiation, Atmospheric and Room Temperature Plasma (ARTP), and laser irradiation (Bleisch et al, 2022).…”

“…UV-C irradiation is optimal for methods utilizing random mutations followed by selection, such as those used for microalgae (Fathy et al, 2023). Mutations caused by UV-C radiation are related to the formation of cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidinone dimers [(6-4) photoproducts] (Bleisch et al, 2022). During this process, it is essential to prevent light-induced (300-600 nm) DNA repair via photoreactivation (Ha and Bhagavan, 2022) by covering the UV-irradiated plates with foil immediately after exposure and incubating them in the dark (Carino and Vital, 2022) for 24-72 h, depending on the cell cycle period.…”

Emerging technologies for advancing microalgal photosynthesis and metabolism toward sustainable production

“…Traditional random mutagenesis, which is generally performed by physical and chemical mutagens, and ALE based on screening of advantageous mutations have demonstrated success in improving photosynthetic efficiency and biomass production. Physical mutagens include ultraviolet (UV) light, ionizing radiation, atmospheric and room temperature plasma (ARTP), and laser radiation (Bleisch et al, 2022). UV radiation induces DNA alterations, especially the formation of pyrimidine dimers while ionizing radiation causes more serious genetic damage, such as chromosomal aberrations.…”

Construction of a Compact Array of Microplasma Jet Devices and Its Application for Random Mutagenesis of Rhodosporidium toruloides

“…1 Under these circumstances, random mutagenesis is still a powerful tool for strain improvement, and mutants obtained in this manner are not considered as genetically modified organisms (GMOs). 2,3 For the past decade, atmospheric pressure and nonthermal plasmas have proven their efficiency as an inactivation tool against bacteria, fungi, and viruses. 4−7 A few examples of the uses of the plasma technology include bacterial inactivation, blood coagulation, tumor treatment, and wound healing.…”

“…Microorganisms with no known ARSs (autonomously replicating sequences), high GC contents, and thick cell walls are generally difficult to introduce targeted genetic perturbations . Under these circumstances, random mutagenesis is still a powerful tool for strain improvement, and mutants obtained in this manner are not considered as genetically modified organisms (GMOs). , …”