Abstract:

This project investigated the rotation of oil droplets driven by motile bacteria adhering to droplets. The dataset consists of: (a) bright field images (.tiff) of oil droplets in cell suspension; (b) z-stack images (.tiff) for droplets with adhering bacteria cell on droplet surface for three species (Halomonas, Shewanella, and Escherichia); (c) movie (.avi) of oil (dodecane and hexadecane) droplets in water for pendant drop analysis for interfacial tension measurement; (d) Contact angle and surface energy of bacteria lawn (.xls); (e) time series (.tiff) of swimming cells in aqueous suspension using confocal microscopy. The folder and file information is detailed in Metadata.xlsx. This dataset supports the publication: Dewangan, N. K., & Conrad, J. C. (2019). Rotating oil droplets driven by motile bacteria at interfaces. Soft Matter, 15(45), 9368–9375. doi:10.1039/c9sm01570a

Suggested Citation:

Narendra K. Dewangan and Jacinta C. Conrad. 2020. Dataset for: Rotating oil droplets driven by motile bacteria at interfaces. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-k407-eb54

Publications:

Dewangan, N. K., & Conrad, J. C. (2019). Rotating oil droplets driven by motile bacteria at interfaces. Soft Matter, 15(45), 9368–9375. doi:10.1039/c9sm01570a

Purpose:

This project was aimed to understand the physics of droplet rotation driven by adhering motile bacteria on droplet surface. We compared the droplet angular speed for different drop sizes, bacteria concentration, bulk surfactant concentration, and different motile bacteria species.

Data Parameters and Units:

Zeta potential: Sample, Mobility (M.U.) mean, Mobility standard deviation, Zeta Potential (mV) mean, Zeta Potential standard deviation (based on three samples). Contact angle and surface energy: Strain (of bacteria), Water contact angle (WCA, [degrees], Diiodomethane contact angle (DIM, [degrees]), Ethylene glycol (EG, [degrees], Surface energy (SE, [mN/m]). Standard deviations are based on at least two lawns of bacteria (individual measurements shown in columns). Within the image data directories, the images are presented in pairs: (a) time series at a position (x,y) and (b) single image at the same position (x,y) but different focal plane on sample. File 'b' is indexed with 'D' (for diameter calculation) after using the same filename as in 'a'. e.g one file is 20191105HT0.2_1.tif and second file is 20191105HT0.2_1D.tiff.

Methods:

Zeta potential of particles and bacteria was measured in MilliQ water using Nicomp 380 ζ-potential analyzer. The contact angle of the three liquids water, ethylene glycol, and diiodomethane was done on bacteria lawn of three bacteria samples; H. titanicae, S. haliotis, and E. coli. by sessile drop method using DataPhysics OCA 15EC goniometer.

Instruments:

Leica Microsystems DM4000 inverted microscope.

Individual Files: