Mechanosensing by Myxococcus Xanthus under Cyclic and Static Substrate Compression

Myxococcus xanthus is a rod-shaped soil bacterium that can sense mechanical cues in its substrate. Under externally applied stress, cells on the surface reorient within minutes, and colonies elongate perpendicular to the compression axis, in a response called elasticotaxis. We investigate whether M. xanthus cells can retain an elasticotactic "memory" of mechanical stress events by testing if the bacterium adapts its collective motility under cyclic loading. We developed a reversible magnet-based agar compression platform that delivers controlled static and cyclic (sinusoidal) stresses with tunable amplitude and direction. We then quantify swarm orientation and aspect ratio, as well as cell orientation and movement (including reversal frequency), during both (i) lateral vs. top-down static compression and (ii) cyclic compression across frequencies. We characterize adaptive signatures, rate- and history-dependent changes such as hysteresis and latency reduction and relate them to hypothesized control via reversal-frequency tuning and local polar order. These measurements will establish whether M. xanthus retains a mechanical memory of prior loading and map regimes where mechanical conditioning influences colony morphology and collective flow.