Final cell counts for cultures of yeast, bacteria, phage B1, and phage B2 growing under aerobic conditions. Experiments conducted in MRS medium at pH 6. Counts of (a) yeast and (b) bacterial cells, measured using microscopy and a counting chamber, are presented. Data are reported for cases where yeasts were grown alone (I); in the presence of bacteria at low inoculation level (II); in the presence of bacteria at high inoculation level (III); in the presence of bacteria at low inoculation level and phages B1 and B2 (IV); and in the presence of bacteria at high inoculation level and phages B1 and B2 (V). Measurements were taken at 20 hours of fermentation. Error bars indicate the standard deviation of three experiments.