Explain the rationale for attached dormancy at ~1,000-cell chains

Determine the evolutionary or physiological rationale underlying the choice by Escherichia coli multicellular chains to attach to surfaces and halt cell division at approximately 1,000 cells during self-organization.

Background

During self-organization, E. coli chains attach at lengths of ~200–400 μm (about 1,000 cells) and simultaneously stop moving and dividing. The authors discuss possible explanations, including nutrient access limitations and activation of the stress-response regulator RpoS prior to attachment, but the definitive purpose of this transition remains unresolved.