Expression of foreign type I ribulose-1,5-bisphosphate carboxylase/ oxygenase (EC 4.1.1.39) stimulates photosynthesis in cyanobacterium Synechococcus PCC7942 cells

Abstract

A reporter gene assay revealed that promoters derived from Synechococcus PCC7942 (S.7942) psbAI and Synechocystis PCC6803 (S.6803) psbAII were suitable for the expression of foreign ribulose-bisphosphate carboxylase (RuBisCO; EC 4.1.1.39) in S.7942 cells. Transformational vectors with a promoter and a foreign RuBisCO gene, cvrbc originated from Allochromatium vinosum, were constructed on a binary vector, pUC303, and introduced to S.7942 cells. When the cvrbc was expressed with the S.7942 psbAI promoter, the total RuBisCO activity increased 2.5- to 4-fold than that of the wild type cell. The S.6803 psbAII promoter increased the activity of the transformant 1.5-2 times of that of wild type cell. There was a significant increase in the rate of photosynthesis depending on the increase of RuBisCO activity. The maximum rate of photosynthesis of the transformant cell was 1.63 times higher than that of the wild type under the illumination of 400 micromol m(-2) s(-1), at 20 mM bicarbonate and at 30 degrees C. Although the photosynthesis of the higher plant is limited by the ability of photosystems under high irradiance and the high CO(2 )concentration, that of the S.7942 cell is limited by the RuBisCO activity, even at high CO(2) concentrations and under high irradiance.

Mechanisms of carbon fixation and engineering for increased carbon fixation in cyanobacteria

“…Therefore, cyanobacteria have developed a CO 2 -concentrating mechanism (CCM) in order to ensure that RuBisCO is surrounded by CO 2 and thereby avoid the oxygenase reaction [15]. Since the cyanobacterial RuBisCO has low affinity for CO 2 , these microorganisms may not have survived in the aquatic habitat without a CCM [16]. Cyanobacteria have developed up to five different transporters to actively acquire and transport inorganic carbon into the cells.…”

Isoprenoid-Based Biofuels: Homologous Expression and Heterologous Expression in Prokaryotes

“…Insertion of sugar transporter systems in cyanobacteria has overcome diurnal running conditions and has provided an excellent alternative for 24-h chemical production (76). Other constraints, such as obtaining maximum photosynthetic efficiency and minimizing heat generation for the optimization of a photo-bioreactor, can be addressed by (i) providing a saturating amount of light (77) and maintaining culture depth and rate of cell mixing to avoid shelf shading (78), (ii) utilizing hyperthermophilic bacteria (79), or (iii) converting nonphotosynthetically active radiation into usable wavelengths (80).…”

Energetic differences between bacterioplankton trophic groups and coral reef resistance

“…Rubisco activity has long been considered the main limiting factor of photosynthesis under saturating irradiance and limiting CO 2 concentrations for higher plants, algae and cyanobacteria [70][71][72][73]. For this reason, an E ¼ 0.32 eV for photosynthesis was used in this study.…”