Growing yeast into cylindrical colonies.
Microorganisms often form complex multicellular assemblies such as biofilms and colonies. Understanding the interplay between assembly expansion, metabolic yield, and nutrient diffusion within a freely growing colony remains a challenge. Most available data on microorganisms are from planktonic cultures, due to the lack of experimental tools to control the growth of multicellular assemblies. Here, we propose a method to constrain the growth of yeast colonies into simple geometric shapes such as cylinders. To this end, we designed a simple, versatile culture system to control the location of nutrient delivery below a growing colony. Under such culture conditions, yeast colonies grow vertically and only at the locations where nutrients are delivered. Colonies increase in height at a steady growth rate that is inversely proportional to the cylinder radius. We show that the vertical growth rate of cylindrical colonies is not defined by the single-cell division rate, but rather by the colony metabolic yield. This contrasts with cells in liquid culture, in which the single-cell division rate is the only parameter that defines the population growth rate. This method also provides a direct, simple method to estimate the metabolic yield of a colony. Our study further demonstrates the importance of the shape of colonies on setting their expansion. We anticipate that our approach will be a starting point for elaborate studies of the population dynamics, evolution, and ecology of microbial colonies in complex landscapes.
Laboratoire Matière et Systèmes Complexes, Centre National de la Recherche Scientifique and Université Paris Diderot, Paris, France.
Clément
C
Vulin
Laboratoire Matière et Systèmes Complexes, Centre National de la Recherche Scientifique and Université Paris Diderot, Paris, France.
Jean-Marc
JM
Di Meglio
Institut National de la Santé et de la Recherche Médicale, Faculté de Médecine, Université Paris Descartes, Paris, France.
Ariel B
AB
Lindner
Laboratoire Matière et Systèmes Complexes, Centre National de la Recherche Scientifique and Université Paris Diderot, Paris, France.
Adrian
A
Daerr
Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts.
Andrew
A
Murray
Laboratoire Matière et Systèmes Complexes, Centre National de la Recherche Scientifique and Université Paris Diderot, Paris, France; The Mechanobiology Institute, National University of Singapore, Singapore. Electronic address: pascal.hersen@univ-paris-diderot.fr.
Pascal
P
Hersen
D001692:Biological Transport; D049109:Cell Proliferation / Q000187:drug effects; D046508:Culture Techniques / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D008567:Membranes, Artificial; D055616:Microtechnology; D016062:Porosity; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
D008567:Membranes, Artificial; D005947:Glucose