Initial and Total Activity of Rubisco in Scenedesmus ecornis: is the French Press a Suitable Tool for Enzyme Extraction?

An enzyme assay was developed to measure the initial and CO₂-Mg²⁺activated forms of Ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco) in the green microalga Scenedesmus ecornis. Comparisonswere made of extraction by mortar and pestle versus the Frenchpress, in the presence or absence of NADPH. Losses due to harvestingand extraction procedures decreased when the algae were collectedunder the same irradiance they had experienced during growth,and by adding NADPH to the extraction solution. Results arediscussed in relation to the possible interactions of effectorswith the enzyme. The suitability of the French press to obtaincatalytic competent extract is questioned. (Received June 5, 1992; Accepted December 9, 1992)