Diatoms’ Breakthroughs in Biotechnology: <i>Phaeodactylum tricornutum</i> as a Model for Producing High-Added Value Molecules

Abstract

With a world growing in population and nutritional needs, diatoms are considered nowadays as microalgae of a very important potential, thus they are exploited in several fields such as ecology, aquaculture, molecular farming, and pharma nutraceuticals. These coveted microalgae are characterized by their diversity, their high division rates, their complex life cycle, likewise their silicified cell walls named frustules. Thus, diatoms have been used for over a century after proving an efficient production of several molecules including Triacylglycerols (TAGs), H 2 , free fatty acids, vitamins, nutraceuticals, amino acids, proteins, terpenoids, alcohols and carbohydrates like starch, glycogen, and sucrose. Phaeodactylum tricornutum is the most promising diatom exploited to date, especially as a platform of pharmaceutical production. Herein, we expose diatoms’ main features that allowed using them for molecular farming. This review exposes likewise, the metabolism and the post-translational modifications (PTMs) of diatoms as well as current tools and challenges for their molecular and metabolic engineering for a more efficient production of valuable molecules. The knowledge on the biology of the diatoms, the molecular tools, and the various transformation methods available demonstrate the potential in biotechnology of these photosynthetic microorganisms. The widely studied P. tricornutum , as a model organism, is a promising diatom for production of valuable metabolites, despite the challenges and issues related to cultivation.