scholarly journals The autotrophic growth of Micrococcus denitrificans on Methanol

1975 ◽  
Vol 150 (3) ◽  
pp. 569-571 ◽  
Author(s):  
R B Cox ◽  
J R Quayle
Keyword(s):  
Specific Activity ◽  
Carbon Assimilation ◽  
High Specific Activity ◽  
Ribulose Bisphosphate Carboxylase ◽  
Autotrophic Growth ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Physiological Evidence

Ribulose bisphosphate carboxylase is present at a high specific activity in extracts of methanol-grown Microccus denitrificans. Enzymic and physiological evidence indicates that, during growth on methanol, the ribulose bisphosphate cycle is the route of carbon assimilation.

Ribulose bisphosphate carboxylase—oxygenase: its role in photosynthesis

1986 ◽  
Vol 313 (1162) ◽  
pp. 305-324 ◽  
Keyword(s):  
Electron Transport ◽  
Carbon Assimilation ◽  
Kinetic Properties ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Rubp Carboxylase ◽  
Bisphosphate Carboxylase ◽  
Triose Phosphate ◽  
Ribulose Bisphosphate Carboxylase Oxygenase

Synthesis of triose phosphate by the chloroplast requires three substrates: light, CO 2 and orthophosphate (P i ). In the response of the rate of carbon assimilation to the concentration of CO 2 , the kinetic properties of RuBP carboxylase-oxygenase (Rubisco) constitute the main limitation at low CO 2 concentrations, while at higher concentrations of CO 2 the limitation is shifted towards the reactions leading to the regeneration of the substrate, RuBP, driven by electron transport. In these circumstances, light or P i or both, can become limiting. The characteristics of Rubisco that can affect photosynthesis fall under three main headings: (1) amount and kinetic constants; (2) activation state; and (3) regulation of catalysis (including the role of effectors, such as Pt and glycerate 3-phosphate (PGA)). These characteristics are analysed, and the role of changes in activity of the enzyme is discussed in the context of limitation and regulation of the photosynthetic process. Other factors considered are the regeneration of RuBP and its relation to electron transport, P i supply, and photorespiration. The influence that expected increases in atmospheric CO 2 concentration, and/or genetic improvements in the characteristics of the enzyme, may have on the present balance between the partial processes of photosynthesis, is discussed.

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