Cyanobacterial cellulose synthesis in the light of the photanol concept

The detailed knowledge already available about cellulose synthases and their regulation, plus emerging insights into the process of cellulose secretion in cyanobacteria make cellulose an attractive polymer for the application of the photanol concept in an economically viable production process. By varying the total complement of antenna pigments, the penetration depth of sunlight into a photo-bioreactor, and thereby the relative fraction of photosynthetically productive cells in it, can be increased. One way to circumvent downstream processing problems is to synthesize a volatile or insoluble product, allowing phase separation. Another way out of the high costs of product recovery from dilute solutions may be found in the coupling of processes, so that the dilute solar biofuel product is converted by a high-affinity biological process into a secondary product in a (photo) chemical conversion in which product separation can be based on phase separation.