A new insight into cell walls of Chlorophyta

Green microalgae, and Chlorophyta in particular, are considered as a renewable source of valuable chemicals for biofuel, nutraceutical or pharmaceutical industries, among others. Microalgae store most of their valuable components inside the cell behind a thick and resistant cell wall. Energy- or solvent-consuming steps are therefore needed to overcome this physical barrier and efficiently extract the desired compounds. Moreover, in a biorefinery context, the wall itself represents a valuable co-product. Although accurate knowledge of microalgal cell walls would be useful for product and process development and overall cost reduction, walls are still poorly understood. High discrepancies in structure and/or composition are regularly described within families, genera or species due to phenotypic plasticity, life cycle stage or erroneous taxonomical classification. Massive progress has been made in this latter research area, which gives, when compiled with the studies focusing on cell walls, a better understanding of micro-algal cell walls. This review focuses on the detailed cell wall structure and composition of Chlorophyta with a particular focus on, but not limited to, industrial micro-algae.