J. Phys. IV France
Volume 125, June 2005
Page(s) 705 - 707

J. Phys. IV France 125 (2005) 705-707

DOI: 10.1051/jp4:2005125161

On-line monitoring of diatom lysis by thermal lens spectrometry

J.K. Logar1, 2, 3, A. Malej2 and M. Franko1

1  Nova Gorica Polytechnic, Vipavska 13, PO Box 301, 5001 Nova Gorica, Slovenia
2  National Institute of Biology, Marine Biology Station Piran, Fornace 41, 6330 Piran, Slovenia
3  Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia

The applicability of a double dual beam thermal lens spectrometer in on-line monitoring of phytoplankton cell lysis was tested in laboratory experiments with cultured diatom Skeletonema costatum. The lysis was induced by the addition of the cytotoxin poly-APS. Increased poly-APS concentration resulted in increased cell lysis and release of cellular pigments into the solution. The associated change in absorbance was monitored as increased difference of TLS signals from lysed and control cultures. The lowest number of decayed cells that can be detected by the double dual beam TLS without any pretreatment or preconcentration of the examined culture is 6.106 to 107 cells/L.

© EDP Sciences 2005