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

Abstract: The major drawbacks of biofuel production at the commercial level are its low yield, nonavailability 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 CRISPRCas9 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.