Figure 1

Phenotypic and physiological traits of the bioethanol yeast strain YJS329. (A) Growth of BYZ1 and YJS329 on plates with and without imposed stresses. Cells were grown in YPD liquid medium at 30°C for 20 h, and 3-μL 10-fold serial dilutions of each sample were spotted onto YPD plates. The YPD plates were then subjected to the indicated stressors. Three independent experiments were conducted, and typical data from one of them are shown. (B) Relative content of physiological and biochemical factors in YJS329. Cells were cultured in YPD for 18 h and then collected. Measurement of the trehalose, glucose-6-phosphate dehydrogenase (G6PD), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), ergosterol, hydroxymethylfurfural (HMF) reductase, palmitic acid (C16:0), palmitoleic acid (C16:1), oleic acids (C18:1), and linoleic acid (C18:2) content was then performed. The values are expressed as log2 ratios (YJS329/BYZ1) that represent the mean of three independent cultured samples (bars indicate SD). (C) Ploidy determination of YJS329 by flow cytometry. The stationary-phase cells of yeast strain BYZ1 (orange), YJS329 (green), and a triploid strain ZTW3 (violet) were fixed with 70% ethanol and stained with propidium iodide. DNA content corresponds to the intensity of red fluorescence. (D) Sporulation efficiency of YJS329. Cells were precultured in YPD and sporulated in sporulation medium. Asci were stained with fluorescein diacetate and then imaged with a confocal laser scanning microscope.