COMPARATIVE STUDIES ON ALDOLASE ACTIVITY IN MARINE PLANKTONIC ALGAE, AND THEIR EVOLUTIONARY SIGNIFICANCE1

Abstract

Fructose dtphosphate aldolase activity was examined n acetone powders and cell-free extracts of 15 photoautotrophLcally grown marine planktonic species belonging to 6 algal divisions as follows: Chlorophyta: Tetraselmls maculata, Dunaliella tertiolecta; Chrysophyta: Monochrysis lutheri, Isochrysls galbana, Prymnesium parvum, Coccolithus huxleyi; Bacillariophyta: Phaeodactylum tricornutum, Skeletonema costatum, Cyclotella nana Cryptophyta: Cryptomonas sp., Rhodomonas lens, Hemiselmis virescens; Pyrrophyta: Amphidinium carteri; Cyanophyta: Anacystls marina, Agmenellum quadruplicatum. Indications of the types of aldolase (Rutter''s classes) present in each alga were obtained from comparative studies of the effects of pH and of the following reagents on the activity: ethylenedlamine tetraacetate, dithiothreitol, p-chloromercuriphenyl sulfonate. Type I (higher plant-animal type) aldolase only was indicated in the 2 chlorophytes, in 1 chrysophyte (M. lutheri), and In 1 bacillarlophyte (P. tricornutum), while the remaining algae appeared to contain either exclusively or principally Type II (bacterial-fungal type) aldolase. The evolutionary implications of these findings are discussed.