Quantifying microbial nutrient limitation and colimitation in the lab and field

Nutrient availability is a fundamental control on marine microbial growth, physiology, metabolic activity, and molecular biology. Global and local environmental changes are altering nutrient availability, and it is important to develop a quantitative understanding of what this means for marine microbiological populations and communities. Traditionally, nutrient limitations are studied individually, however there is evidence that microbes can be, and often are, simultaneously limited by multiple resources (colimitation). revious work on colimitation has considered limitation as a binary property (e.g. the resource is limiting or not), and nearly everything that is known about microbial growth and physiology is form a state of strong single nutrient limitation. In this talk, I will discuss recent theoretical and experimental evidence that suggests that clonal populations of bacteria experience nutrient colimitation. I will introduce metrics of nutrient limitation and colimitation that allow for a quantitative perspective on these states, and show data indicating that heterotrophic bacteria experience colimitation for two essential resources (such as glucose and ammonium). I will also provide preliminary evidence that that there is a distinct proteomic response to colimitation, suggesting that by focusing on extreme single nutrient limitation scenarios, we are missing out on key aspects of microbial adaptation and molecular biology. Altogether these findings strengthen the case for increased consideration of nutrient colimitation in biogeochemical, biotechnology, and oceanography contexts, particularly in the process of developing molecular biomarkers of microbial growth and activity and in monitoring the effects of environmental change.

Presentation Preference: Oral

Primary Presenter: Noelle Held, University of Southern California (nheld@usc.edu)

Authors:

Noelle Held, University of Southern California  (nheld@usc.edu)

Mia Franks, University of Southern California  (mgfranks@usc.edu)

Alexander Devaux, University of Southern California  (devaux@usc.edu)

Donat Crippa, ETH-Zurich  (donat.crippa@usys.ethz.ch)

Aswin Krishna, ETH-Zurich  (aswin.krishna@env.ethz.ch)

Michael Manhart, Rutgers University  (mmanhart@rutgers.edu)