The enhancement of CO2 fixation in isolated, intact spinach chloroplasts by ascorbate or by low sulfite concentrations (less than 1 mM) is strongly reduced or even abolished by the addition of superoxide dismutase (SOD). By the use of 35SO3(2-) it is demonstrated that the rate of sulfate formation is much lower than the sulfite induced increase in CO2 fixation. This indicates that the superoxid...

Cyanobacteria have attracted much attention as hosts to recycle CO2 into valuable chemicals. Although cyanobacteria have been engineered to produce various compounds, production efficiencies are too low for commercialization. Here we engineer the carbon metabolism of Synechococcus elongatus PCC 7942 to improve glucose utilization, enhance CO2 fixation and increase chemical production. We introd...

The ultimate goal of this research is to construct a new direct CO2 fixation system using photosystems in living algae. Here, we report light-driven formate production from CO2 by using cyanobacterial photosystem I (PS I). Formate, a chemical hydrogen carrier and important industrial material, can be produced from CO2 by using the reducing power and the catalytic function of formate dehydrogena...

sence of exogenously added glutamate and pyridoxal-5'-phosphate and produced radioactive aspartate in the presence of these components. Reduced nicotinamide adenine dinucleotide or reduced nicotinamide adenine dinucleotide phosphate could not be substituted for adenosine triphosphate (ATP); phosphoenolpyruvate even in the presence of nucleoside diphosphates could not replace pyruvate plus ATP; ...

The effects of H2 gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO2 dynamics and microbial activity and composition were analyzed. The H2 emission rate of 250 nmol H2 g K1 soil h was similar to the upper limit of estimated H2 amounts emitted from N2 fixing nodules into the surrounding soil ([Dong, Z., L...

Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation ((14)C-SOC) in CT soils was significantly hig...

The key components of crassulacean acid metabolism (CAM) - nocturnal fixation of atmospheric CO2 and its processing via Rubisco in the subsequent light period - are now reasonably well understood in terms of the biochemical reactions defining this water-saving mode of carbon assimilation. Phenotypically, however, the degree to which plants engage in the CAM cycle relative to regular C3 photosyn...

BACKGROUND AND AIMS White lupin is highly adapted to growth in a low-P environment. The objective of the present study was to evaluate whether white lupin grown under P-stress has adaptations in nodulation and N2 fixation that facilitate continued functioning. METHODS Nodulated plants were grown in silica sand supplied with N-free nutrient solution containing 0 to 0.5 mm P. At 21 and 37 d aft...

We investigated carbon acquisition by the N2-fixing cyanobacterium Trichodesmium IMS101 in response to CO2 levels of 15.1, 37.5, and 101.3 Pa (equivalent to 150, 370, and 1000 ppm). In these acclimations, growth rates as well as cellular C and N contents were measured. In vivo activities of carbonic anhydrase (CA), photosynthetic O2 evolution, and CO2 and HCO { 3 fluxes were measured using memb...

Following field observations of increased photosynthesis at increased rates of sediment flushing in sandy sediments, we conducted a series of laboratory experiments to elucidate the mechanism behind these observations. Column experiments in which water was pumped though sand at rates ranging from 0 to 613 L m22 d21 showed that carbon (C) fixation, as measured using carbon-14 (14C) incorporation...