Bio-photolysis of water by microalgae and cyanobacteria Microalgae are primitive microscopic plants living in aqueous environments. Cyanobacteria, formerly known as blue-green algae, are now recognized as bacteria since the anatomical characteristics of their cells are prokaryotic (bacterial type). Miroalgae and Cyanobacteria along with higher plants, are capable of oxygenic photosynthesis according to the following reaction: