Biofluiddynamics of lubricating bacteria

I. Cohen, I. Golding, I. G. Ron, E. Ben-Jacob

Research output: Contribution to journalArticle

Abstract

Various bacterial strains exhibit colonial branching patterns during growth on thin poor substrates. The growth can be either diffusion-limited or kinetic-limited, according to the imposed growth conditions. We present experimental observations of patterns exhibited by the bacterial strains Paenibacillus dendritiformis and Paenibacillus vortex. All manners of branching patterns are observed, the three main being: (1) basic branching; (2) chiral branching; (3) vortex branching. We show that the following biological features can explain the spectrum of observed patterns: (1) Formation of a lubricating fluid. (2) Food chemotactic. (3) Attractive and repulsive chemotactic signaling. (4) Flagella handedness. (5) Transition into pre-spore state. In the theoretical studies we employ knowledge drawn from branching patterning in non-living systems and the mathematical properties of reaction-diffusion models and atomistic models. The above can be used not just to describe existing biological understanding, but also to derive new understanding. For example, reaction-diffusion models that include bacterial density and nutrient concentration, can exhibit branching dynamics if the growth term is a meta-stable fixed point or if the diffusion is state dependent. We show that biologically the growth term has to be an unstable fixed point, but that state-dependent diffusion can represent the lubrication fluid excreted by the bacteria.

Original languageEnglish (US)
Pages (from-to)1429-1468
Number of pages40
JournalMathematical Methods in the Applied Sciences
Volume24
Issue number17-18
DOIs
StatePublished - Nov 25 2001
Externally publishedYes

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ASJC Scopus subject areas

  • Mathematics(all)
  • Engineering(all)

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