Tiny Cell, Global Impact: What Prochlorococcus can teach us about Life


Thursday, June 16, 2011
Redfield Auditorium - 12:00 Noon
Dr. Penny Chisholm
Professor Dept. of Civil and Env. Engineering, Dept. of Biology, MIT

Discovered only 25 years ago, Prochlorococcus is the smallest and most abundant oxygenic phototroph on Earth.   It sometimes accounts for as much as 50% of the chlorophyll in the oligotrophic oceans, and is often the dominant photosynthesizer at the base of the euphotic zone.   This group of minimal phototrophs is comprised of closely related but genetically and physiologically distinct ‘ecotypes’ that display different relative abundances along ocean gradients.  Genome sequences from cultured strains, phages that infect them, and genomes from wild cells are providing new insights into the origins and dynamics of micro-diversity within the global population of Prochlorococcus.  As such, this ‘federation’ of microbes serves as a useful model to begin to understand life processes at all scales of organization, from the cell to the biosphere.