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1.- E. coli metapopulation on-chip Ecosystem

Fluorescent (GFP) and motile E.coli cells living on a synthetic patchy ecosystem consisting of an array of MHPs in real time. Using nano and micro fluidics, we can use landscape ecology to design habitat structures to study the cellular and molecular biophysics of complex bacterial ecosystems. From Island biogeography to evolutionary biophysics. Time in the video is real time. Collective swimming behavior also emerges in some MHPs.


 

2.- E. coli metapopulation on-chip Ecosystem

Macroscopic dynamics snapshots of movie #1 (above) taken every 10 minutes intervals now to illustrate the long-term meta-population dynamics of bacteria. Complex microbial metapopulation dynamics (colonization-extinction of local habitat patches) an be observed as well as biofilm assembly and disassembly.


 

3.- Shape-shifting through squeezing bacteria

Very early on we discovered that bacteria are amazingly plastic and can squeeze through amazingly narrow constrictions. Here can see shape-shifting cells as they squeeze through an ecological corridor connecting two adjacent MHPs which is smaller in size than of normal-shape (N-forms) cells. Thus, cell resembling L-forms can be generated on-chip by inducing shape-shifting morphologies on-chip. Cells are attracted to the right side of the landscape by chemotaxis towards better habitat quality.


 

4.- Prisoner-Dilemma game for a 2-strain E.coli meta-community on-chip

Here an array MHPs implementing a linear habitat landscape hosting a 2-strains E.coli meta-community of defector (red; rpoS 819) and cooperator cells (green; rpoS wt) while undergoing a tragedy of the commons in an on-chip. Red cells (rpoS 819) defect the wt’s “social contract” for entry into stationary-phase in mixed populations. In spatially explicit habitat landscapes (the importance of being spatial and discrete), a much more interesting story unfolds.


5.- Rock-Paper-Scissor game for a 3-strain E.coli meta-community on-chip

Here an array MHPs implementing a linear habitat landscape hosting a 3-strains E.coli meta-community playing the Rock (colicin resistant & red), Paper (colicin producer & blue), and Scissor (colicin sensitive wt & green) game on-chip. The emergence of non-transitive competitive hierarchies is of paramount importance for the maintenance of biodiversity.

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6.- Shape-shift and resist

shape-shifting allows E. coli to resists antibiotic ampicillin. A 3 ecotope landscape is build. In order to migrate from ecotope 1 (top left; 1.5 um deep) to another suitable environment for normal-shape cells ecotope 3 (bottom right; 1.5 um deep), cells have to shape-shift and disperse through ecotope 2 (center; 200 nm deep) reaching ecotone 3 at t = 1 hr. Ampicillin step in concentration is resisted by subpopulations in ecotones 2 and 3 survive and re-invade ecotone 1.


 

7.- Prisoner dilemma and competition for space in a lattice theory of social conflict

Theoretical model of  war for territory (competition for space) and social conflict (prisoner’s dilemma). Cooperator (green) and defector (red) particles replicate to near-by available locations (empty space in black) and die out at rates depending on local configurations which distribute costs and benefits among players.

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