Fig. 5

Comparing growth and ethanol formation of CS4435L in residual whey permeate medium with two different nitrogen sources. The medium only contains diluted residual whey permeate (RWP) without the addition of any vitamin or salt, except yeast extract (YE) or corn steep liquor hydrolysate (CSLH) as nitrogen sources. a The fermentation was carried out in diluted RWP medium containing initially 32 g/L lactose and 0.5 % (w/v) yeast extract; b The fermentation was carried out in diluted RWP medium containing initially 40 g/L lactose and 2.5 % (w/v) CSLH. CSLH was prepared based on H1 condition (CSL treated with 0.05 % H₂SO₄). Cell density (filled squares), lactose concentration (filled circles), and ethanol concentration (filled triangles) are displayed. Experiments were conducted in duplicate and error bars indicate standard deviations