Single-Cell Growth Kinetics of Algae, Chlorela Vulgaris

Single-cell growth kinetics of algae, Chlorela vulgaris

Alim Dewan, Jihye Kim, Swastika S. Bithi, Marci Kerls, Siva A. Vanapalli, M. Nazmul Karim*

Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409, USA.

*E-mail: naz.karim@ttu.edu

 

Abstract

Traditionally, the growth kinetics of algae is investigated using cell culture equipment that contains large number of cells.  The kinetic parameters are measured from representative samples of the cell culture and the measured parameters represent the statistical average of all the cells in the samples. In this study, we have investigated the growth kinetics of single-cell of Chlorella vulgaris using droplet based PDMS microfluidic chip. The kinetic parameters were determined by counting the total number of cells under investigation during the entire period of the experiment. We found that there is significant heterogeneity in the growth and size of single cells and kinetic parameters are different even if the initial cell numbers are the same. We found that there is significant heterogeneity in the growth and size of single cells and kinetic parameters are different even if the initial cell numbers are the same. Figure 1exmplifies the heterogeneity of single-cell growth kinetics. We hypothesize that the heterogeneity occurs due to the difference in initial cell conditions such as the age of the cell, and the size.  

Figure1. Example of single-cell growth curves. Inset shows the initial cell number (N_o), final cell number (N_t) and the specific growth rate (µ).