Breeding strategies for YJS329. (A) After heat and ethanol treatment, the moderate up-expression of HSF1 in YJS329 improved its viability. Strains YJS329 and YJS329 + BYHSF1 (the HSF1 from BYZ1was expressed in YJS329) were pre-cultured in YPD medium and 1 mL cells (cell density was adjusted to OD600 = 1) were then subjected to either heat (55°C, 6 min) or ethanol (15% v/v in YPD liquid medium, 10 h) treatments. The “a” indicates a significant difference between YJS329 + BYHSF1 and YJS329 (B) The impact of deletion of FPS1 and overexpression of ALD6 on the YJS329 fermentation process. The fermentation medium contained 220 g/L glucose, 10 g/L yeast extract, 20 g/L peptone. Data represent mean ± SD of three individual cultures. The “a” indicates a significant difference between YJS329ΔFPS1 and YJS329; “b” indicates a significant difference between YJS329ΔFPS1ALD6 and YJS329ΔFPS1 using the t test at the 0.05 level. (C) Deletion of FPS1 and overexpression of ALD6 improved the viability ratio of after treatment with ethanol (15%, v/v) and lignocellulosic hydrolysate (LH, containing 4 g/L acetic acid, 1 g/L furfural, and 1 g/L 5-HMF, pH4.5) for 10 h. The “a” and “b” letters have the same meaning as in Figure 5B.