SYMMETRIC DIVISION. “We find that the old pole is a significant marker for multiple phenotypes associated with aging, namely, decreased metabolic efficiency (reduced growth rate), reduced offspring biomass production, and an increased chance of death. Thus, E. coli, an organism with a morphologically symmetrical division, no juvenile phase, and no identified separation between germ line and soma, is susceptible to aging.”
http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0030045