Example 5
Each DNA construct was integrated into Saccharomyces cerevisiae (CEN.PK2) with standard molecular biology techniques in an optimized lithium acetate (LiAc) transformation. Briefly, cells were grown overnight in yeast extract peptone dextrose (YPD) media at 30° C. with shaking (200 rpm), diluted to an OD600 of 0.1 in 100 mL YPD, and grown to an OD600 of 0.6-0.8. For each transformation, 5 mL of culture was harvested by centrifugation, washed in 5 mL of sterile water, spun down again, resuspended in 1 mL of 100 mM LiAc, and transferred to a microcentrifuge tube. Cells were spun down (13,000×g) for 30 seconds, the supernatant was removed, and the cells were resuspended in a transformation mix consisting of 240 μL 50% PEG, 36 μL 1 M LiAc, 10 μL boiled salmon sperm DNA, and 74 μL of donor DNA. For transformations that required expression of the endonuclease F-CphI, the donor DNA included a plasmid carrying the F-CphI gene expressed under the yeast TDH3 promoter for expression. This will cut the F-CphI endonuclease recognition site in the landing pad to facilitate integration of the UGT gene. Following a heat shock at 42° C. for 40 minutes, cells were recovered overnight in YPD media before plating on selective media. DNA integration was confirmed by colony PCR with primers specific to the integrations.
