S. xylosus produces the highest FAME activity of all surveyed CNS strains. S. xylosus isolates were assayed for FAME activity/log CFU over 24 h. CFUs were generally the same among the strains with the beginning of stationary phase indicated by the arrow. Results are the average of three experiments. Vertical bars represent standard error of the observation; if no bar is apparent the standard error is smaller than the symbol. S. xylosus isolates had detectable FAME activity at 20 h (P < 0.05).