Studies on autotrophic CO2 fixation by the filamentous anoxygenic photosynthetic bacterium Oscillochloris trichoides strain DG-6 demonstrated that, unlike other green bacteria, this organism metabolized CO2 via the reductive pentose phosphate cycle. Both key enzymes of this cycle--ribulose-1,5-bisphosphate carboxylase/oxygenase and phosphoribulokinase--were detected in cell extracts. The main p...

The authors have developed and validated a photosynthetic-sterility model for grain production monitoring under the background of climate change and Asian economic growth in developing countries. This paper presents an application of the model to evaluate car-bonfixation rates in yields of paddy rice, winter wheat, and maize in Asia. The validation of the model is based on carbon partition-ing ...

Populations of genetically identical microorganisms residing in the same environment can display marked variability in their phenotypic traits; this phenomenon is termed phenotypic heterogeneity. The relevance of such heterogeneity in natural habitats is unknown, because phenotypic characterization of a sufficient number of single cells of the same species in complex microbial communities is te...

In the process of photosynthesis in Cklorella it is now known that the oxygen liberated during CO2 fixation and reduction originates from water (Ruben et al., 1941). I t is further known that in some algae (not ChloreUa) one can obtain carbon dioxide fixation and reduction without the release of oxygen (by adaptation to hydrogen, Gaffron, 1940, 1942 a, 1942 b, Gaffron and Rubin, 1942) and that ...

To predict effects of climate change and possible feedbacks, it is crucial to understand the mechanisms behind CO2 responses of biogeochemically relevant phytoplankton species. Previous experiments on the abundant N2 fixers Trichodesmium demonstrated strong CO2 responses, which were attributed to an energy reallocation between its carbon (C) and nitrogen (N) acquisition. Pursuing this hypothesi...

A global ocean biogeochemical model is used to quantify the sensitivity of marine biogeochemistry and air–sea CO2 exchange to variations in dust deposition over decadal timescales. Estimates of dust deposition generated under four climate states provide a large range in total deposition with spatially realistic patterns; transient ocean model experiments are conducted by applying a step-functio...

The unicellular cyanobacterium Cyanothece sp. American Type Culture Collection (ATCC) 51142 is capable of performing oxygenic photosynthesis during the day and microoxic nitrogen fixation at night. These mutually exclusive processes are possible only by temporal separation by circadian clock or another cellular program. We report identification of a temperature-dependent ultradian metabolic rhy...

Biological carbon dioxide fixation is an essential and crucial process catalyzed by both prokaryotic and eukaryotic organisms to allow ubiquitous atmospheric CO2 to be reduced to usable forms of organic carbon. This process, especially the Calvin-Bassham-Benson (CBB) pathway of CO2 fixation, provides the bulk of organic carbon found on earth. The enzyme ribulose 1,5-bisphosphate (RuBP) carboxyl...

Geologists have suggested that life might have emerged at hydrothermal vents, chemists have shown that metal sulphides such as FeS and NiS can catalyse biochemical reactions in the absence of proteins, and biologists have suggested that the acetyl-coenzyme-A (CoA) pathway of CO2 fixation might be very ancient. New findings from the enzymes at the heart of the acetyl-CoA pathway, carbon monoxide...