On-line monitoring of diatom lysis by thermal lens spectrometry

Abstract
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.