A hydrodynamic-stochastic model of chemotactic ciliated microorganisms
Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur, India
2 Center for Theoretical Studies, Indian Institute of Technology Kharagpur, Kharagpur, India
Accepted: 10 January 2019
Published online: 21 February 2019
Biological systems like ciliated microorganisms are capable of responding to the external chemical gradients, a process known as chemotaxis. In this process, the internal signaling network of the microorganism is triggered due to binding of the chemoattractant molecules with the receptors on the surface of the body. This can alter the activity at the surface of the microorganism. We study the chemotaxis of ciliated microorganisms using the chiral squirmer model, a spherical body with a surface slip velocity. In the presence of a chemical gradient, the coefficients of the slip velocity get modified resulting in a change in the path followed by the body. We observe that the strength of the gradient is not the only parameter which controls the dynamics of the body but also the adaptation time plays a very significant role in the success of chemotaxis. The trajectory of the body is smooth if we ignore the discreteness in the ligand-receptor binding which is stochastic in nature. In the presence of the latter, the path is not only irregular but the whole dynamics of the body changes. We calculate the mean first passage time, by varying the strength of the chemical gradient and the adaptation time, to determine the success rate of chemotaxis.
Key words: Living systems: Biomimetic Systems
© EDP Sciences, SIF, Springer-Verlag GmbH Germany, part of Springer Nature, 2019