Fucus serratus L., Fucus spiralis L., and Fucus vesiculosus L. (Fucales, Phaeophyceae) as well as Laminaria digitata (Huds.) Lamour., Laminaria hyperborea (Gunn.) FosI., and Laminaria saccharina (L.) Lamour. (Laminariales, Phaeophyceae) have been investigated for the distribution of enzymic CO2 fixation capacities via phosphoenolpyruvate carboxykinase (EC 4.1.1.32) (PEP-CK) and via ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39) (RubP-C) in different regions of the thalli. The maximum of PEP-CK activity is found to be confined to the growing regions of the algae, while the activity of RubP-C achieves its highest values in the entirely differentiated parts of the fronds. These findings are confirmed by the results of photosynthetic and light-independent (dark) carbon assimilation as determined by in vivo 14C02 fixation. The physiological significance of these differential patterns of carboxylation patterns is discussed with respect to the ontogenetic stage and the chemical constitution of the different thallus parts.The thalli of a variety of marine benthic macroalgae, particularly those of the Fucales and Laminariales (Phaeophyceae) are morphologically and histologically of relatively high structural complexity-in some regards implicating direct analogies to the equivalent features of the cormophytes. This is presumably allied with an appropriate functional specialization of different thallus parts. Noticeable properties of developmental behavior such as the circa-annual growth rhythms (10) or certain physiological peculiarities such as the demonstration of long distance translocation of stored assimilation products in the case of the Laminariales (6, 11, 12) may lead to this assumption.The thallus differentiation of brown algal species may partly be described in terms of biochemical and physiological properties. Gradients of chemical constitution in a Laminaria species have already been mentioned (2, 3). Furthermore, a differential distribution of certain carboxylating enzymes within the thallus of Laminaria hyperborea could be demonstrated (13). Another study showed that frond development of this species and "'C-labeling percentages of certain assimilates are intimately correlated (14). Chemical constitution and a variety of physiological characters of different thallus regions of Fucus serratus have been analyzed (7).A comparative investigation on enzymic CO2 fixation as well as experiments on nature and kinetics of early '4C-labeled assimilates of carbon fixation in various marine algae revealed that particularly the brown algal species so far investigated contain considerable amounts of P-enolpyruvate carboxykinase accounting for relatively high rates of light-independent carbon assimilation (8).The present study is concerned with this phenomenon, too. With special respect to the peculiar biochemical features of the ' Supported by the Deutsche Forschungsgemeinschaft.Phaeophyceae so far examined (8) KUPPERS AND KREMERof the thalli as the samples investigated for carbon fixation and enzyme act...

Vortrag anlai3lich der Verleihung der Schleiden-Medaille gibt hiervon Zeugnis.Nicht unerwahnt bleiben sollten auch seine bedeutenden wissenschaftspolitischen Aktivitaten. In vielbeachteten brillanten Vortragen und Publikationen hat er der Offentlichkeit die Stellung der Biowissenschaften an deutschen Universitaten und die Bedeutung der Naturwissenschaft fur unsere Gesellschaft vermittelt.

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Parmotrema chinense (Osbeck) Hale and Ahti, comb. nov. Lichen chinensis Osbeck, Ostindisk resa, 221, 1757. Type: Specimen in the Dillenian herbarium (OXF) (illustrated in pl. 20, fig. 39B of Dillenius, Hist. Musc. 147, 1742). Lichen perlatus Huds., Fl. Angl. 448. 1762, nom. illeg. (incl. type of Lichen chinensis Osbeck). Parmelia perlata Ach., Meth. Lich. 216. 1803, nom. illeg. (incl. type of L. chinensis Osbeck). [Note: Under Art. 49, parenthetic author citation is correct only if the epithet-bringing name is legitimate. Under Art. 72, Note 1 and Ex. 2-3, parenthetic author citation is deleted if the epithet-bringing name is illegitimate.]

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Experiments on short-term photosynthesis in H(14)CO3 (-) (2-5 s) using various species of different algal classes resulted in predominant (14)C-labelling (>90% of total (14)C-incorporation) of phosphorylated compounds. The percentage of malate and aspartate usually accounts for distinctly less than 10% of the total (14)C-labelling. These findings are consistent with data from enzymatic analyses, since 97-100% of the carboxylation capacity is due to ribulose-1.5-biphosphate carboxylase (EC 4.1.1.39) in Rhodophyceae and Chlorophyceae. Phaeophyceae are generally characterized by considerable activity of phosphoenolpyruvate carboxykinase (EC 4.1.1.32): at least 10% of carboxylation is confined to this enzyme. Similar ratios are obtained when rates of photosynthesis and of light-independent CO2-fixation are compared. Activity of phosphoenolpyruvate carboxylase (EC 4.1.1.31) could not be detected in the species investigated. The results are discussed with emphasis on the pathway of photosynthetic carbon assimilation in marine algae.

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