Growth of early Cit+ clones in DM25 medium
Figure: Growth of Early Cit+ Clones in DM25 Medium: Three early Cit+ clones were sampled from aliquots of population Ara-3 that were frozen at generations 32,000 (black symbols), 32,500 (green symbols), and 33,000 (blue symbols). The clones were propagated for four days in DM25 prior to starting the growth curves. Each trajectory shows the average of six replicate curves for a given clone. All three 32,000-generation clones showed little or no growth on citrate even by 48 h. All three 33,000-generation clones exhibited substantial growth on citrate. Two 32,500-generation clones underwent little or no growth on citrate even by 48 h, whereas one of the 32,500-generation clones grew on citrate but at a rate substantially slower than any of the three 33,000-generation clones. Cit+ clones were a minority in all three generational samples based on screening 1,280 clones, chosen at random from each sample, on Christensen’s citrate agar (Blount et al., 2008, page 7901).