2.2 Media and culture condition
Escherichia coli TOP10 and E. coli transformants were cultured in Luria-Bertani medium (tryptone 10 g/L, yeast extract 5 g/L and NaCl 10 g/L) with or without antibiotics at 37°C. The yeast strains were grown on yeast peptone dextrose (YEPD) medium (Bacto peptone 20 g/L, yeast extracts 10 g/L, glucose 10 g/L or varied amount of sugar tested). For the selection of the recombinants, formaldehyde was added to the medium with a final concentration of 5.5 mM (22).