Investigation of interactions and dynamic behaviors of <i>S</i>. <i>cerevisiae</i> and <i>C</i>. <i>acetobutylicum</i> under each stress environments.

<p><b>(A)</b> Cells growth and ethanol synthesis in <i>S</i>. <i>cerevisiae</i> cultivation. Horizontal shadow: Initial cells concentration (OD₆₀₀); slashed shadow: increased cells concentrations (OD₆₀₀); white: ethanol concentration. <b>(B)</b> The concentrations of the four amino acids favorable for <i>C</i>. <i>acetobutylicum</i> survival and butanol synthesis in <i>S</i>. <i>cerevisiae</i> cultivation. Black: lysine; white: methionine; horizontal shadow: phenylalanine; slashed shadow: tyrosine. None and B&B referred to the cases of no any ingredients additions and simultaneously adding butanol and butyrate, respectively. <b>(C)</b> Impacts of exogenous ethanol addition on ABE fermentation by <i>C</i>. <i>acetobutylicum</i>. Black: butanol; white: acetone; slashed shadow: ethanol produced by <i>C</i>. <i>acetobutylicum</i>; horizontal shadow: added ethanol; ●: gas production amount. EtOH5 and EtOH10: 5 g-ethanol/L and 10 g-ethanol/L were added. <b>(A)</b>-<b>(B)</b><i>S</i>. <i>cerevisiae</i> seeds were incubated in a rotating shaker at 200 r/min and 30°C for 24 h and then transferred into the anaerobic bottles. The cultivation continued for 36 h. <b>(C)</b> The fermentations ended at 60 h, ethanol was added at 24 h.