Stochastic force dynamics of the model microswimmer Chlamydomonas reinhardtii: Active forces and energetics

A brief introduction to the model microswimmer {\it Chlamydomonas reinhardtii}

The unicellular biflagellate green alga {\it Chlamydomonas reinhardtii} has been an important model system in biology for decades, and in recent years it has started to attract growing attention also within the biophysics community. Here we provide a concise review of some of the aspects of {\it Chlamydomonas} biology and biophysics most immediately relevant to physicists that might be interested in starting to work with this versatile microorganism.

Phototaxis beyond turning: persistent accumulation and response acclimation of the microalga Chlamydomonas reinhardtii

Phototaxis is an important reaction to light displayed by a wide range of motile microorganisms. Flagellated eukaryotic microalgae in particular, like the model organism Chlamydomonas reinhardtii, steer either towards or away from light by a rapid and precisely timed modulation of their flagellar activity. Cell steering, however, is only the beginning of a much longer process which ultimately allows cells to determine their light exposure history. This process is not well understood. Here we present a first quantitative study of the long timescale phototactic motility of Chlamydomonas at both …

流体动力学相互作用导致莱衣藻（Chlamydomonas reinhardtii）在固液界面附近聚集

Hydrodynamic interaction leads to the accumulation of Chlamydomonas reinhardtii near a solid-liquid interface

本研究利用三维实时追踪显微系统证实了莱衣藻在固液界面附近的聚集现象，并提出由两对相互垂直力偶极子组成的简化模型，从流体动力学相互作用角度为其提供了理论解释。

Effective viscosity of non-gravitactic Chlamydomonas Reinhardtii microswimmer suspensions

Active microswimmers are known to affect the macroscopic viscosity of suspensions in a more complex manner than passive particles. For puller-like microswimmers an increase in the viscosity has been observed. It has been suggested that the persistence of the orientation of the microswimmers hinders the rotation that is normally caused by the vorticity. It was previously shown that some sorts of algaes are bottom-heavy swimmers, i.e. their centre of mass is not located in the centre of the body. In this way, the algae affects the vorticity of the flow when it is perpendicular oriented to the ax…

Re-enterant efficiency of phototaxis in Chlamydomonas reinhardtii cells

Phototaxis is one of the most fundamental stimulus-response behaviors in biology wherein motile micro-organisms sense light gradients to swim towards the light source. Apart from single cell survival and growth, it plays a major role at the global scale of aquatic ecosystem and bio-reactors. We study photoaxis of single celled algae Chalmydomonas reinhardtii as a function of cell number density and light stimulus using high spatio-temporal video microscopy. Surprisingly, the phototactic efficiency has a minimum at a well-defined number density, for a given light gradient, above which the photo…

Chlamydomonas reinhardtii鞭毛器的多粒子碰撞动力学模拟

Multiparticle Collision Dynamics Simulations of the Flagellar Apparatus in Chlamydomonas reinhardtii

该研究使用多粒子碰撞动力学模拟Chlamydomonas reinhardtii鞭毛器的游动行为，发现非零平均曲率FA维持弹道运动，而零平均曲率FA0无法实现净推进，且活跃拍动不影响旋转扩散，为人工微游泳者设计提供蓝图。