2.2. Preparation of TC and cell immobilizationTC was produced after delignification of sawdust by alkaline treatment (boilingwith 1% w/v NaOH) as previously described [15], and it was sterilized by autoclavingat 130◦C for 15 min. Cell immobilization was carried out by suspending 16 g of theharvested yeast culture in 800 ml of 12% w/v glucose medium containing 100 g of TC.The system was allowed to ferment overnight at 30◦C until all sugar was utilized.The liquid was then decanted and the biocatalyst was washed twice with 400 ml offresh glucose medium. Amounts of 100 g (wet weight) of the biocatalyst and 4.9 g(wet weight) of harvested yeast culture were frozen to −45◦C at a cooling rate of3◦C/min in a controlled rate freezer (BioCool, FTS Systems, NY, USA), with no addi-tions of cryoprotecting media. The frozen samples were then freeze-dried overnightat 5 × 10−3bar and −45◦C in a Freeze Dry System, Freezone 4.5 (Labconco, KansasCity, MO, USA). The dried biocatalysts were then used for the following fermentationexperiments.