Stock cultures of S. cerevisiae laboratory reference
strain CEN.PK 113-7D were grown in shake flasks in 100 ml medium
containing 1% (wt/vol) Bacto yeast extract, 2% (wt/vol) Bacto peptone,
and 2% (wt/vol) glucose. Pentose-fermenting S. cerevisiae strain IMS0010
(45) was cultivated in synthetic medium (41) containing 2% (wt/vol)
arabinose. After the addition of 30% (vol/vol) glycerol to stationary-phase
cultures, 1-ml aliquots were stored at 80°C.