On-line monitoring of cell growth in plant tissue cultures by conductometry

Use of conductivity change in the medium for the on-line monitoring of cell mass growth was investigated in cultures of Coffea arabica, Nicotiana tabacum, Withania somnifera, and Catharanthus roseus. It was found that the effect of pH (4.5–7.0) and sugar concentration (0–1%) changes on medium conductivity can be neglected. Linear relationships between the dry cell mass and conductivity change were observed for all the four cell lines: ΔX = k ( Δκ), where the coefficient k = 3.6, 2.8, 3.2, and 4.1 g · cm · l −1 · ms −1 for C. arabica, N. tabacum, W. somnifera, and C. roseus, respectively. By this method it was possible to estimate the cell mass concentrations in situ during the growth phase for various plant cell cultures.