Inactivation of Yarrowia lipolytica YlACL2 gene Coding Subunit of ATP Citrate Lyase Using CRISPR/Cas9 System

In this study, YlACL2 was inactivated by two methods: traditional approach based on homologous recombination and uracil marker and markerless system using CRISPR/Cas9. The efficiency of YlACL2 inactivation using traditional approach was 4% (one Δ Ylacl2 strain out of 24 tested transformants) whereas knockout efficiency using CRISPR/Cas9 system was 75% (18 Δ Ylacl2 strains out of 24 tested transformants). YlACL2 null mutant strains were not able to utilize citrate as a single carbon source. Growth kinetics was investigated in the media with glucose and acetate as a single carbon source. The fact that Δ Ylacl2 is able to grow in the minimal medium with glucose as a single carbon source provides evidence that there is an alternative source of acetyl-CoA on carbohydrate substrates in Y . lipolytica .