Emerging Technologies for the Discovery of Novel Diversity in Cyanobacteria and Algae and the Elucidation of Their Valuable Metabolites

Until recently, the study of cyanobacteria and microalgae has been hampered by the need to cultivate these organisms to gain insight into their cytomorphology, life cycle and molecular biology. However, various microbial species characterized by thick sheaths of exopolymeric substances were difficult to isolate in culture due to their associated symbiotic bacteria. Other microbes evaded culture. Such challenges have now been overcome by the development of metagenomic techniques that allow direct DNA sequencing from environmental samples, as well as high resolution microscopy techniques that permit direct imaging of environmental samples. The sampling of understudied taxa from extreme environments and of toxic species has been facilitated by specialized robotic equipment. Single-cell sequencing has allowed for the proper characterization of microalgal species and their response to environmental changes. Various strains of cyanobacteria, microalgae and macroalgae have gained renewed interest for their high-value metabolites. This paper provides an overview of the emerging technologies and explains how they are being used to identify such strains and their products for industrial application. Advances in genetic engineering and CRISPR technology have facilitated the production of strains that are more amenable to culture, metabolite extraction, scale-up and application in biorefinery approaches. Emerging analytical techniques are discussed, with the advent of multiomics and its application in this field.