  Recent experiments have been able to visualise chromosome organization in
fast-growing E.coli cells. However, the mechanism underlying the
spatio-temporal organization remains poorly understood. We propose that the DNA
adopts a specific polymer topology as it goes through its cell cycle. We
establish that the emergent entropic forces between polymer segments of the
DNA-polymer with modified topology, leads to chromosome organization as seen
in-vivo. We employ computer simulations of a replicating bead spring model of a
polymer in a cylinder to investigate the problem. Our simulation of the
overlapping cell cycles not only show successful segregation, but also
reproduces the evolution of the spatial organization of the chromosomes as
observed in experiments. This manuscript in addition to our previous work on
slowly growing bacterial cells, shows that our topology-based model can explain
the organization of chromosomes in all growth conditions.
