The Photoassimilation of Organic Compounds by Autotrophic Blue-green Algae

The role of plastoquinone in the in vivo photosynthetic cyclic electron transport pathway in algae

“…It was not possible to demonstrate the photoassimilation or the aerobic utilization of acetate or glucose in this red alga even after dark starvation or after long periods of growth in the presence of these organic substrates. Thus the basis for the obligate autotrophy of red algae would appear to be different from that of the blue-green algae which do show some very limited photoheterotrophy [ 16,17 ]. These results are in agreement with those of Urbach and Kaiser [14] and I also conclude that the in vivo cyclic pathway for organic substrate photoassimilation in algae includes PQ and that the pathway is most likely identical to the cyclic transport which is utilized during certain phases of CO 2 fixation.…”

The Incomplete Tricarboxylic Acid Cycle in the Blue-green Alga Anabaena Variabilis

“…4. The absence of a-oxoglutarate dehydrogenase and succinyl-CoA synthetase activity prevents cyclic flow, and this is consistent with the entry of [14C]acetate into only a limited number of amino acids, first observed by Hoare & Moore (1965). The synthesis of oxoloacetate, and hence the aspartate family of amino acids, could arise from the carboxylation of pyruvate or phosphoenol pyruvate.…”

“…This restricted flow of [14C]carbon from acetate into a limited number of related amino acids had also been reported in 4 . niduluns (Hoare & Moore, 1965;Hoare et al 1967) and by Kelly (1967) in Thiobacillus neapolitanus. The present communication presents enzymic evidence for an incomplete tricarboxylic acid cycle in A .…”

“…The photosynthetic autotrophically grown blue-green algae have been shown to metabolize acetate (Hoare & Moore, 1965;Carr & Pearce, 1966). Although isocitratase and malate synthetase were detected at low activities in extracts of Anacystis nidulans and Anubaena variabilis (Pearce & Carr, I 967a), incorporation of [14C]acetate into A. nidulans gave no evidence for a glycoxylate cycle operation and indicated that the tricarboxylic acid cycle did not proceed further than a-oxoglutarate (Hoare, Hoare & Moore, 1967).…”

Effect of Some Physical and Chemical Factors on the Germination of Akinetes of Anabaena Cylindrica

“…Most of acetate carbon was incorporated into amino acids such as glutamate and leucine (Table 9). A similar situation has already been reported for vegetative cells in some blue-green algae (15)(16)(17)(18)(19)(20). WoLK (21) reported that acetate stimulated sporulation of Anabaena cylindrica.…”