New Applications of Synthetic Biology Tools for Cyanobacterial Metabolic Engineering

Abstract

Cyanobacteria are promising microorganisms for sustainable biotechnologies, yet unlocking their potential requires radical re-engineering and application of cutting-edge synthetic biology techniques. In recent years, the available devices and strategies for modifying cyanobacteria have been increasing, including advances in the design of genetic promoters, ribosome binding sites, riboswitches, reporter proteins, modular vector systems, and markerless selection systems. Because of these new toolkits, cyanobacteria have been successfully engineered to express heterologous pathways for the production of a wide variety of valuable compounds. Cyanobacterial strains with the potential to be used in real-world applications will require the refinement of genetic circuits used to express the heterologous pathways and development of accurate models that predict how these pathways can be best integrated into the larger cellular metabolic network. Herein, we review advances that have been made to translate synthetic biology tools into cyanobacterial model organisms and summarize experimental and in silico strategies that have been employed to increase their bioproduction potential. Despite the advances in synthetic biology and metabolic engineering during the last years, it is clear that still further improvements are required if cyanobacteria are to be competitive with heterotrophic microorganisms for the bioproduction of added-value compounds.

Comparative analysis of inducible promoters in cyanobacteria

“…This includes well-studied model organisms such as Synechocystis sp . PCC 6803 6 , Synechococcus elongatus PCC 7942 7,8 and Anabaena sp . PCC 7120 9 , but also some more recently discovered, fast-growing strains, such as Synechococcus elongatus UTEX 2973 10 or Synechococcus sp .…”

Energy conservation in photosynthetic microorganisms

“…Production of ethanol for biofuel has increased in some countries through fermentation from starch and cellulose (Radakovits et al, 2010). Ethanol could be synthesized in Chlamydomonas cells in the night (Hirano et al, 1997) and in gene-manipulated cyanobacteria (Radakovits et al, 2010;Santos-Merino et al, 2019). Ethanol could be synthesized in Chlamydomonas cells through degradation and fermentation of intracellular starch.…”

“…There is a growing interest in developing technology for renewable energy production to deal with the shortage of fossil fuel and with global warming caused possibly by the increase in carbon dioxide atmospheric concentration. Photosynthesis-biological energy conversion of solar radiation to organic compounds-has been considered as one of the appropriate methods to resolve these problems (Radakovits et al, 2010;Stephens et al, 2010;Stephenson et al, 2011;Santos-Merino et al, 2019). Photosynthesis is distributed in a wide variety of organisms, such as terrestrial higher plants, seaweeds, microalgae, and cyanobacteria.…”

Bioengineering tools for the production of pharmaceuticals: current perspective and future outlook

“…As a result of novel toolkits, microbes have been effectively bioengineered to express diverse heterologous paths for the generation of an extensive variation of treasured bio-compounds. In silico approaches have been active in an upsurge their bioproduction possibility [81].…”