Implications of CRISPR-Cas9 in Developing Next Generation Biofuel: A Mini-review

The major drawbacks of biofuel production at the commercial level are its low yield, non-availability of feedstock, feedback inhibition, presence of inhibitory pathways in various organisms, and biofuel intolerance of organisms. The present review focuses on the implications of the CRISPR-Cas9 mediated gene editing tool to alter the genome of bacteria, algae, fungi, and higher plants for efficient biofuel production. Gene knockout and gene cassette insertions employing CRISPR-Cas9 in Saccharomyces cerevisiae and Kluyveromyces marxianus have resulted in enhanced production of bioethanol and 2-Phenyl ethanol in these organisms, respectively. Genomes of several bacterial strains were also modified to enhance ethanol and butanol production in them. CRISPR-Cas9 modification of microalgae has demonstrated improved total lipid content, a prerequisite for biofuel production. All over, CRISPR-Cas9 has emerged as a tool of choice for engineering the genome and metabolic pathways of organisms for producing industrial biofuel. In plant-based biofuel production, the biosynthetic pathways of lignin interfere with the satisfactory release of fermentable sugars thus hampering efficient biofuel production. CRISPR-Cas9 has shown a promising role in reducing lignin content in various plants including barley, switchgrass, and rice straw.