Effects of overexpressing photosynthetic carbon flux control enzymes in the cyanobacterium Synechocystis PCC 6803.
Synechocystis PCC 6803 is a model unicellular cyanobacterium used in e.g. photosynthesis and CO2assimilation research. In the present study we examined the effects of overexpressing Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), sedoheptulose 1,7-biphosphatase (SBPase), fructose-bisphosphate aldolase (FBA) and transketolase (TK), confirmed carbon flux control enzymes of the Calvin-Bassham-Benson (CBB) cycle in higher plants, in Synechocystis PCC 6803. Overexpressing RuBisCO, SBPase and FBA resulted in increased in vivo oxygen evolution (maximal 115%), growth rate and biomass accumulation (maximal 52%) under 100μmolphotonsm-2s-1light condition. Cells overexpressing TK showed a chlorotic phenotype but increased biomass by approximately 42% under 100μmolphotonsm-2s-1light condition. Under 15μmolphotonsm-2s-1light condition, cells overexpressing TK showed enhanced in vivo oxygen evolution. This study demonstrates increased growth and biomass accumulation when overexpressing selected enzymes of the CBB cycle. RuBisCO, SBPase, FBA and TK are identified as four potential targets to improve growth and subsequently also yield of valuable products from Synechocystis PCC 6803.
Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
Feiyan
F
Liang
Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden. Electronic address: Peter.Lindblad@kemi.uu.se.
Peter
P
Lindblad
D002244:Carbon / Q000378:metabolism*; D049109:Cell Proliferation / Q000502:physiology; D004798:Enzymes / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology / Q000528:radiation effects; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology / Q000528:radiation effects; D008027:Light; D060847:Metabolic Engineering / Q000379:methods*; D064688:Metabolic Flux Analysis / Q000379:methods; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D010788:Photosynthesis / Q000502:physiology* / Q000528:radiation effects; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D015854:Up-Regulation / Q000502:physiology
D004798:Enzymes; D002244:Carbon
CcmM; FBA; RuBisCO; SBPase; Synechocystis PCC 6803; TK