Carbon dioxide fixation byThiobacillus versutus: apparent absence of a CO2-concentrating mechanism in organisms grown under carbon-limitation in the chemostat

Proposed carbon dioxide concentrating mechanism in Chlamydomonas reinhardtii.

Kinetics and Apparent K(m) of Oxygen Cycle under Conditions of Limiting Carbon Dioxide Fixation.

A mass spectrometer with a membrane inlet was used to monitor light-driven O(2) evolution, O(2) uptake, and CO(2) uptake in suspensions of algae (Scenedesmus obliquus). We observed the following. (a) The rate of O(2) uptake, which, in the presence of iodoacetamide, replaces the uptake of CO(2), showed a distinct plateau (V(max)) beyond approximately 30% O(2) and was half-maximal at approximatel...

The mechanism of enzymatic carbon dioxide fixation into oxal-acetate.

Studies of the non-enzymatic decarboxylation of /3-keto acids have shown that it is the keto form of the 8-keto acid which loses CO2 to form an enol of the product. This was demonstrated for dimethylacetoacetic acid by Pedersen (1) and for dimethyloxalacetic acid by Steinberger and Westheimer (2). These latter authors studied the catalytic effect of metal ions on the decarboxylation reaction an...

Carbon dioxide fixation in the brain.

Upon intracarotid administration of ammonia to cats, there is a significant increase of cerebral glutamine without a corresponding decrease in the level of cerebral glutamic acid (3). Similar observations in dogs have been reported by others (4). Since the supply of glutamic acid from the circulating blood is insufficient for the formation of the additional amount of glutamine, the dicarboxylic...

Transcriptome-wide changes in Chlamydomonas reinhardtii gene expression regulated by carbon dioxide and the CO2-concentrating mechanism regulator CIA5/CCM1.

We used RNA sequencing to query the Chlamydomonas reinhardtii transcriptome for regulation by CO(2) and by the transcription regulator CIA5 (CCM1). Both CO(2) and CIA5 are known to play roles in acclimation to low CO(2) and in induction of an essential CO(2)-concentrating mechanism (CCM), but less is known about their interaction and impact on the whole transcriptome. Our comparison of the tran...