Award: OCE-1129359

Microbes are by far the most abundant organisms on the planet, occurring at millions to billions of cells even in small volumes of environmental samples. Through their growth, these organisms contribute heavily to the global carbon cycle, modulating the availability of nutrients for plants and playing a key role in climate regulation. But we have very little idea how fast microbes grow in their natural environments, which range from ocean to the gut. This proposal developed novel devices that allow the measurement of both how much a single bacterium weighs and how fast it grows in natural samples. This enabled precise measurement of the biomass of even the smallest bacterial cells in the ocean and differentiation of biomass of fast and slow growing bacteria. Significant progress was also made in measuring single cell growth rates under realistic environmental conditions and capturing the same cells after these measurements in order to determine their genome sequence. Such data are crucial for parameterizing models of global carbon cycling more accurately and for predicting when certain types of microbes grow in the environment, including beneficial or harmful bacteria. This development has also implications for diagnostics in medical applications and aspects of the technology have been licensed for further development. The work contributed to the education and research of several graduate and undergraduate students, and to the professional development of several postdoctoral researchers. As an outreach activity, several undergraduates produced a series of podcasts describing the work and the process of generating science. These podcasts are freely available on the web. Last Modified: 04/24/2017 Submitted by: Martin F Polz