None. All claims in the abstract were satisfied by the data presented. We do suggest editing this section of the abstract:
Here we show that exponentially dividing Bacillus subtilis cultures divide into distinct interacting metabolic subpopulations including one population that produces acetate, and another population that differentially expresses metabolic genes for the production of acetoin, a pH-neutral storage molecule. These subpopulations grew at distinct rates, and cells switched dynamically between states, with acetate influencing the relative sizes of the different subpopulations.
When we first read the abstract, we expected cells switching back and forth between alsS+ and sucC+ cells; actually, cells at OD600 0.8 switch from sucC+ to a "normal" state and likewise for OD600 2.0 and alsS+. The meaning is clear after reading the paper.