초록
<P><B>Abstract</B></P> <P>Among biomass materials available, macroalgae is a promising alternative to traditional energy crops. The absence of lignin, a high growth rate and a richness of fermentable sugars and nitrogen, are real gains for a competitive ethanol production. But the presence of salts can be an obstacle to obtain relevant performances. Experiments were carried out with a synthetic medium adjusted on algal hydrolysate composition in order to reduce resource limitations and variations of composition. The behavior of four yeast strains for ethanol production was investigated: <I>Candida guilliermondii</I>, <I>Scheffersomyces stipitis</I>, <I>Kluyveromyces marxianus</I> and <I>Saccharomyces cerevisiae</I>. Glucose, which is the most abundant sugar in the targeted algal hydrolysate (<I>Ulva</I> spp), was completely assimilated by all of the considered strains, even in the presence of salts at levels found in macroalgal hydrolysates (0.25 M of sodium chloride and 0.21 M of sulfate). The use of peptone as nitrogen source enhanced kinetics of consumption and production. For instance, the rate of ethanol production by <I>S. cerevisiae</I> in the presence of peptone was six times higher than that obtained using ammonium, 0.6 and 0.1 g L<SUP>−1</SUP> h<SUP>−1</SUP> respectively. In the presence of salts, the rates of glucose consumption and ethanol production were lowered for the considered strains, except for <I>K. marxianus</I>. Nevertheless, <I>S. cerevisiae</I> could be the most promising strain to valorize <I>Ulva</I> spp hydrolysate in bioethanol, in terms of ethanol produced (7.5–7.9 g L<SUP>−1</SUP>) whether in the presence or in absence of salts.</P>