### Abstract

Spiroplasma swimming is studied with a simple model based on resistive-force theory. Specifically, we consider a bacterium shaped in the form of a helix that propagates traveling-wave distortions which flip the handedness of the helical cell body. We treat cell length, pitch angle, kink velocity, and distance between kinks as parameters and calculate the swimming velocity that arises due to the distortions. We find that, for a fixed pitch angle, scaling collapses the swimming velocity (and the swimming efficiency) to a universal curve that depends only on the ratio of the distance between kinks to the cell length. Simultaneously optimizing the swimming efficiency with respect to interkink length and pitch angle, we find that the optimal pitch angle is 35.5° and the optimal interkink length ratio is 0.338, values in good agreement with experimental observations.

Original language | English (US) |
---|---|

Article number | 218102 |

Journal | Physical Review Letters |

Volume | 102 |

Issue number | 21 |

DOIs | |

State | Published - May 26 2009 |

Externally published | Yes |

### Fingerprint

### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Physical Review Letters*,

*102*(21), [218102]. https://doi.org/10.1103/PhysRevLett.102.218102

**Kinematics of the swimming of spiroplasma.** / Yang, Jing; Wolgemuth, Charles William; Huber, Greg.

Research output: Contribution to journal › Article

*Physical Review Letters*, vol. 102, no. 21, 218102. https://doi.org/10.1103/PhysRevLett.102.218102

}

TY - JOUR

T1 - Kinematics of the swimming of spiroplasma

AU - Yang, Jing

AU - Wolgemuth, Charles William

AU - Huber, Greg

PY - 2009/5/26

Y1 - 2009/5/26

N2 - Spiroplasma swimming is studied with a simple model based on resistive-force theory. Specifically, we consider a bacterium shaped in the form of a helix that propagates traveling-wave distortions which flip the handedness of the helical cell body. We treat cell length, pitch angle, kink velocity, and distance between kinks as parameters and calculate the swimming velocity that arises due to the distortions. We find that, for a fixed pitch angle, scaling collapses the swimming velocity (and the swimming efficiency) to a universal curve that depends only on the ratio of the distance between kinks to the cell length. Simultaneously optimizing the swimming efficiency with respect to interkink length and pitch angle, we find that the optimal pitch angle is 35.5° and the optimal interkink length ratio is 0.338, values in good agreement with experimental observations.

AB - Spiroplasma swimming is studied with a simple model based on resistive-force theory. Specifically, we consider a bacterium shaped in the form of a helix that propagates traveling-wave distortions which flip the handedness of the helical cell body. We treat cell length, pitch angle, kink velocity, and distance between kinks as parameters and calculate the swimming velocity that arises due to the distortions. We find that, for a fixed pitch angle, scaling collapses the swimming velocity (and the swimming efficiency) to a universal curve that depends only on the ratio of the distance between kinks to the cell length. Simultaneously optimizing the swimming efficiency with respect to interkink length and pitch angle, we find that the optimal pitch angle is 35.5° and the optimal interkink length ratio is 0.338, values in good agreement with experimental observations.

UR - http://www.scopus.com/inward/record.url?scp=66349117009&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66349117009&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.102.218102

DO - 10.1103/PhysRevLett.102.218102

M3 - Article

C2 - 19519138

AN - SCOPUS:66349117009

VL - 102

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 21

M1 - 218102

ER -