Engineering Synechocystis sp. PCC 6803 using CRISPR/Cas9 for leveraging the stable production of biofuels derived from isoprenoids and methyl-ketones

Climate change is a menacing and imminent issue that is endangering our existence in this planet. The accumulation of harmful CO2 emissions, primarily from the burning of fossil fuels, are aggravating the current situation. As a result, biofuels have emerged as an alternative to fossil-based fuels in order to tackle climate change. However, their elevated production costs and the lower energy per litre they provide when compared to fossil-fuels have significantly commercial realisation of biofuels. Hence, a new biofuel production strategy is necessary. Methyl ketones and terpenoids produced by Synechocystis sp. PCC 6803 are an innovative alternative that may result in low production costs and high energy. Synechocystis sp. PCC 6803 is a cyanobacteria that, recently, has attracted the attention as a biofuel producer as well as for the production of several other valuable compounds. However, hindrances regarding its genetic engineering have hindered its potential as a cell factory, leaving it behind model organisms such as E. coli and S. cerevisiae. Therefore, a new genetic engineering strategy for Synechocystis is needed to leverage the cyanobacterium and generate biofuels with low production costs and high energy. Hence, in this work, the genetic engineering of Synechocystis sp. PCC 6803 via CRISPR/Cas9 is reviewed to produced biofuels derived from methyl ketones and terpenoids. A strategy for harvesting Synechocystis using chitosan has also been optimised to further lower energy input and therefore lower costs associated with production of biofuels using Synechocystis.