Fig. 1. Effect of SO2 addition on the growth of S. cerevisiae (A) and P. fermentans (B). YPD medium was prepared in three conditions: non-SO2
(x), 0.1 g/l (.), 0.2 g/l (). The cultures were inoculated with 106 colony forming units (cfu)/ml and were maintained at 28 8C in constant
agitation. Aliquots were taken and plated to count the number of colonies per millilitre at each time.