Spatially-Resolved Metabolic Cooperativity within Dense Bacterial Colonies
http://www.biomedcentral.com/content/pdf/s12918-015-0155-1.pdf). The researchers show that E. coli cells within a colony naturally differentiate into distinct metabolic phenotypes depending on their location. “Pioneer” cells at the outer edge engage in rapid growth that expands the colony, while dormant cells in the interior separate two spatially distinct subpopulations linked by a cooperative form of acetate crossfeeding (wherein one population makes acetate as a byproduct, and the other consumes it). Intriguingly, the closest known analogue of this crossfeeding actually occurs in certain types of cancer wherein cells on the inside and outside of the tumor have been observed crossfeeding lactate. With help from CPLC post-docs Jingye Fei and Ben Leslie, as well as microscopy specialists in the Core Facilities at the Carl Woese Institute of Genomic Biology, the researchers performed fluorescence imaging experiments that clearly indicated the existence of separate sugar-consuming and acetate-consuming subpopulations, strongly supporting their simulated results.