Synthetic Biology Toolkits for Metabolic Engineering of Cyanobacteria

Abstract

Cyanobacteria are of great importance to Earth's ecology. Due to their capability in photosynthesis and C1 metabolism, they are ideal microbial chassis that can be engineered for direct conversion of carbon dioxide and solar energy into biofuels and biochemicals. Facilitated by the elucidation of the basic biology of the photoautotrophic microbes and rapid advances in synthetic biology, genetic toolkits have been developed to enable implementation of nonnatural functionalities in engineered cyanobacteria. Hence, cyanobacteria are fast becoming an emerging platform in synthetic biology and metabolic engineering. Herein, the progress made in the synthetic biology toolkits for cyanobacteria and their utilization for transforming cyanobacteria into microbial cell factories for sustainable production of biofuels and biochemicals is outlined. Current techniques in heterologous gene expression, strategies in genome editing, and development of programmable regulatory parts and modules for engineering cyanobacteria towards biochemical production are discussed and prospected. As cyanobacteria synthetic biology is still in its infancy, apart from the achievements made, the difficulties and challenges in applying and developing genetic toolkits in cyanobacteria for biochemical production are also evaluated.

Emerging Species and Genome Editing Tools: Future Prospects in Cyanobacterial Synthetic Biology

“…Basic Boolean logic functions include ‘AND’ and ‘NOT’ gates: AND gates will give an output signal if all inputs are ‘ON’, while NOT gates will give an output signal only if all inputs are ‘OFF’ [147,211,212]. To date, relatively few synthetic genetic circuits have been constructed in cyanobacteria [213]. These include an oxygen-responsive AND gate in PCC 6803 [214] and four NOT gate variants in PCC 6803, PCC 7942, Nostoc PCC 7120, Synechocystis sp.…”

Progress and challenges in engineering cyanobacteria as chassis for light‐driven biotechnology

“…As discussed above, CRISPR‐ and recombinase‐based genome engineering also require expression of plasmid‐borne genes (Tan et al , ; Wendt et al , ). However, the use of plasmids in cyanobacterial genetic engineering is somewhat limited; only pRSF1010 derivatives or fusions of native cyanobacterial and E. coli plasmids have been widely used in cyanobacteria due to stability issues with other platforms (see Xia et al , for an overview of replicative plasmids in cyanobacteria). A better understanding of cyanobacterial plasmid replication and the development of exogenous self‐replicating vectors based on alternatives to the RSF1010 backbone would be of great benefit to the cyanobacterial metabolic engineering community.…”

Efficient engineered probiotics using synthetic biology approaches: A review

“…This plays a vital role in the evolution of a biological unit, facilitates targeted diagnostics and therapies. The innovations in a microorganism based on genetic circuit possess sole capabilities to transform the applications of engineered microorganisms . This will help to overcome the number of challenges such as biological containment, metabolic regulation, biotherapeutics, and diagnostics.…”