Skip to main content

Advertisement

Table 1 Basic physiological parameters of PCC6803 under different steady conditions with ammonium or nitrate as N source

From: Electron balancing under different sink conditions reveals positive effects on photon efficiency and metabolic activity of Synechocystis sp. PCC 6803

  LLHC HLHC HLLC
NH4 NO3 NH4 NO3 NH4 NO3
D (day−1) 1.15 1.13 2.45 2.83 0.77 0.74
X (mgCDW l−1) 107 ± 10 111 ± 7 63 ± 1 58 ± 1 120 ± 4 91 ± 3
c(Chla) (mgChla l−1) 2.18 ± 0.29 2.64 ± 0.22 1.50 ± 0.07 1.63 ± 0.10 1.41 ± 0.09 1.05 ± 0.03
ChlaCDW (µgChla mg CDW −1 ) 20.4 ± 4.6 23.8 ± 3.5 23.8 ± 1.5 27.7 ± 2.2 11.7 ± 1.1 11.5 ± 1.1
Y(PSII) (–) 0.50 ± 0.01 0.60 ± 0.01 0.34 ± 0.01 0.52 ± 0.01 0.16 ± 0.01 0.21 ± 0.03
a*phy (m2 g Chl a −1 ) 15.0 ± 0.8 14.0 ± 0.4 14.5 ± 0.1 15.2 ± 0.2 18.3 ± 1.3 17.9 ± 1.6
Qphar (mmol quanta mg CDW −1  day−1) 1.28 ± 0.16 1.36 ± 0.09 6.20 ± 0.37 7.28 ± 0.59 3.56 ± 0.55 3.73 ± 0.38
rF (µmol O2 mg CDW −1  day−1) 81.5 ± 10.8 102.3 ± 6.6 260.6 ± 23.0 469.4 ± 48.3 68.1 ± 7.4 108.3 ± 11
rO (µmol O2 mg CDW −1  day−1) 28.9 ± 7.7 34.2 ± 7.9 84.5 ± 16.1 142.8 ± 21.2 39.9 ± 6.4 44.8 ± 4.9
rresp (µmol O2 mg CDW −1  day−1) 7.7 ± 1.7 13.3 ± 3.0 19.7 ± 3.3 24.3 ± 4.5 5.2 ± 1.0 5.9 ± 0.4
PQ (mol mol−1) 1.8 ± 0.1 1.9 ± 0.1 1.5 ± 0.1 1.7 ± 0.1 1.6 ± 0.1 1.6 ± 0.1
C/N (mol mol−1) 4.67 ± 0.02 4.69 ± 0.13 4.61 ± 0.01 4.86 ± 0.07 5.23 ± 0.14 5.39 ± 0.14
  1. Mean values and standard deviations correspond to 3–12 samples (depending on the parameter, see “Materials and methods” section) taken during at least three different days for the same metabolic state. LLHC, low light (65 µmol photons m−2 s−1) and high carbon (1% CO2) condition; HLHC, high light (250 µmol photons m−2 s−1) and high carbon condition (1% CO2); HLLC, high light (250 µmol photons m−2 s−1) and low carbon condition (ambient CO2); D, dilution rate equaling the specific growth rate µ in the respective steady state; X, biomass concentration; c(Chla), volumetric chlorophyll a concentration; ChlaCDW; biomass-specific Chla content; Y(PSII), effective quantum yield at PSII; a*phy, Chla dependent absorption coefficient of the cells; Qphar, rate of quantum uptake; rF, fluorescence-based electron flux at PSII; rO, net O2 evolution rate; rresp, respiration rate; PQ, photosynthetic quotient defined by the ratio of O2 evolution and CO2 uptake; C/N, molar ratio of carbon and nitrogen in biomass