Recent trends in the biotechnological production of tocopherols using in vitro cultures

Abstract

Tocopherols, a class of terpenoid compounds with vitamin-E activity, are produced by photosynthetic organisms, including cyanobacteria, algae, and plants. The chemical structure of tocopherols consists of a hydrophobic prenyl tail linked to a polar chromanol head. Depending on the position and number of methyl groups on the chromanol head, tocopherols are classed as a, b, c, and d isomers. Tocopherols play a key role in plant defense, and have bioactive properties beneficial for human health, being reported to prevent atherosclerosis, Parkinson’s and Alzheimer’s diseases, eyesight degeneration, diabetes, and coronary heart disease. The high market demand for tocopherols calls for new strategies to improve their supply from sustainable sources, and a promising approach is to develop biotechnological factories with tocopherol-producing plant and microalgae in vitro cultures. This review provides a detailed overview of different strategies devised to enhance tocopherol production using such systems, with particular focus on elicitation and feeding, culture conditions, and the application of metabolic engineering.