Intertemporal trade-off between population growth rate and carrying capacity during public good production

Manasi S Gangan; Marcos M Vasconcelos; Urbashi Mitra; Odilon Câmara; James Q Boedicker

doi:10.1016/j.isci.2022.104117

Intertemporal trade-off between population growth rate and carrying capacity during public good production

iScience. 2022 Mar 19;25(4):104117. doi: 10.1016/j.isci.2022.104117. eCollection 2022 Apr 15.

Authors

Manasi S Gangan¹, Marcos M Vasconcelos², Urbashi Mitra³, Odilon Câmara⁴, James Q Boedicker^{1

5}

Affiliations

¹ Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, USA.
² Commonweath Cyber-Initiative and Bradley Department of Electrical Engineering, Virginia Polytechnic Institute and State University, Arlington, VA, USA.
³ Ming Hsieh Department of Electrical & Computer Engineering, Department of Computer Science, University of Southern California, Los Angeles, CA, USA.
⁴ USC Marshall School of Business, University of Southern California, Los Angeles, CA, USA.
⁵ Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.

Abstract

Public goods are biomolecules that benefit cellular populations, such as by providing access to previously unutilized resources. Public good production is energetically costly. To reduce this cost, populations control public good biosynthesis, for example using density-dependent regulation accomplished by quorum sensing. Fitness costs and benefits of public good production must be balanced, similar to optimal investment decisions used in economics. We explore the regulation of a public good that increases the carrying capacity, through experimental measurements of growth in Escherichia coli and analysis using a modified logistic growth model. The timing of public good production showed a sharply peaked optimum in population fitness. The cell density associated with maximum public good benefits was determined by the trade-off between the cost of public good production, in terms of reduced growth rate, and benefits received from public goods, in the form of increased carrying capacity.

Keywords: Computational molecular modeling; Microbiology.