摘要 |
<p>The invention relates to a process for the aerobic propagation of yeast wherein the yeast is grown in a reactor, comprising the following steps: a) filling the reactor with carbon source and an initial yeast population, b) optionally growing the initial yeast population in the reactor in batch mode, c) measuring the pH in the reactor, d) adding lignocellulosic hydrolysate to the reactor in fed batch mode at a rate to set the pH in the reactor at a predetermined value, and e) after sufficient propagation, isolation of yeast from the reactor. The invention further relates to yeast propagated according to that propagation process and to a process for the production of fermentation product wherein sugar comprising hexose and pentose is anaerobically fermented to fermentation product with the propagated yeast.</p> |