Microbial Active Matter: A Topological Framework

Abstract

Topology transcends boundaries that conventionally delineate physical, biological and engineering sciences. Our ability to mathematically describe topology, combined with our access to precision tracking and manipulation approaches, has triggered a fresh appreciation of topological ramifications, specifically in mediating key functions in biological systems spanning orders of magnitude in length and time scales. Microbial ecosystems, a frequently encountered example of living matter, offer a rich test bed where the role of topological defects and their mechanics can be explored in the context of microbial composition, structure and functions. Emergent processes, triggered by anisotropy and activity characteristic of such structured, out-of-equilibrium systems, underpin fundamental properties in microbial systems. An inevitable consequence of anisotropy is the long-range orientational (or positional) correlations, which give rise to topological defects nucleating due to spontaneous symmetry breaking. The scene stealer of this emerging cross-disciplinary field is the topological defects: singularities embedded within the material field that elicit novel, if not unexpected, dynamics that are at the heart of active processes underpinning soft and living matter systems. In this short review, I have put together a summary of the key recent advances that highlight the interface of liquid crystal physics and the physical ecology of microbes; and combined it with original experimental data on sessile species as a case to demonstrate how this interface offers a biophysical framework that could help to decode and harness active microbial processes in 'true' ecological settings. Topology and its functional manifestations - a crucial and well-timed topic - offer a rich opportunity for both experimentalists and theoreticians willing to take up an exciting journey across scales and disciplines.

9 pages, 5 figures

References in corpus (25)

• Active Particles in Complex and Crowded Environments
• Motility-Induced Phase Separation
• Bacterial hydrodynamics
• Topological defect launches 3D mound in the active nematic sheet of neural progenitors
• The statistical physics of active matter: from self-catalytic colloids to living cells
• Command of active matter by topological defects and patterns
• Defect dynamics in active nematics
• Hydrodynamics of topological defects in nematic liquid crystals
• Defect-mediated morphologies in growing cell colonies
• Enhanced bacterial swimming speeds in macromolecular polymer solutions
• Thermodynamic phases in two-dimensional active matter
• Vorticity, Defects and Correlations in Active Turbulence
• Verticalization of bacterial biofilms
• Emergence of active nematics in bacterial biofilms
• Enhanced active swimming in viscoelastic fluids
• The propagation of active-passive interfaces in bacterial swarms
• Cross-talk between topological defects in different fields revealed by nematic microfluidics
• Effective dynamics of microorganisms that interact with their own trail
• Enhanced propagation of motile bacteria on surfaces due to forward scattering
• Mono-to-multilayer transition in growing bacterial colonies
• Nutrient transport driven by microbial active carpets
• Self-organization of swimmers drives long-range fluid transport in bacterial colonies
• Propagation of active nematic-isotropic interfaces on substrates
• Subpopulations and Stability in Microbial Communities
• Defect dynamics in growing bacterial colonies

Cited by in corpus (10)

• Topological defects promote layer formation in Myxococcus xanthus colonies
• Drying of Bio-colloidal Sessile Droplets: Advances, Applications, and Perspectives
• A review of active matter reviews
• Particle-resolved topological defects of smectic colloidal liquid crystals in extreme confinement
• Trade-offs in phenotypic noise synchronize emergent topology to actively enhance transport in microbial environments
• Collective mechano-response dynamically tunes cell-size distributions in growing bacterial colonies
• Tilt-induced polar order and topological defects in growing bacterial populations
• Substrate stiffness modulates bacterial adhesion and diversity of adherent phenotypes across growth stages
• Toward a realistic model of multilayered bacterial colonies
• Mobility-induced phase separation in a binary mixture of active Brownian particles