Fig. 2
Construction of amylolytic S. cerevisiae M2n and ER industrial strains. The ENO1 temA and temG_Opt gene cassettes (a) were amplified using PCR and contained flanking regions homologous to the δ-integration sites. The TEF1P–amdS-TEF1T cassette was cloned onto yBBH1 (b) to generate the yBBH1–amdSYM yeast expression vector. Soluble starch plate assays to visualise hydrolysis zones surrounding the recombinant strains (c), following incubation on soluble starch at 30 °C. The S. cerevisiae M2n and ER parental strains displayed no extracellular amylase activity. Ethanol concentrations produced by S. cerevisiae recombinant strains during fermentation in YPD with 5 g l−1 glucose and with 200 g l−1 corn starch at 30 °C (d) were compared to the parental strains. Data are the mean of three repeats showing standard deviation