At least four successive batches were made to each fermentation medium prior to change to the following medium with increased inhibitor levels. Adaptation was monitored by calculating the specific maximum glucose consumption rate of each batch, measured at 10% or less of the initial glucose remaining in the reactor. After the CRBF adaptation, the obtained strain (Y-265A3) was cultivated on YM agar plates supplemented with 1 g/L furfural and 4 g/L acetic acid for maintenance and further evaluation, since culture in synthetic inhibitor-containing solid medium (E medium) proved unfeasible.