Li 190sa quantum sensor

A glucose-tolerant strain of Synechocystis sp. PCC 6803 (here after referred to as GT) was obtained from Prof. Masahiko Ikeuchi of the University of Tokyo. Synechocystis sp. PCC 6803 was routinely cultured in BG11 medium, which contained 1.5 g L⁻¹ NaNO₃, 0.04 g L⁻¹ K₂HPO₄, 0.075 g L⁻¹ MgSO₄ · 7H₂O, 36 mg L⁻¹ CaCl₂ · 2H₂O, 6 mg L⁻¹ citric acid, 6 mg L⁻¹ ferric ammonium citrate, 1 mg L⁻¹ EDTA (disodium salt), 20 mg L⁻¹ NaCO₃, 2.86 mg L⁻¹ H₃BO₃, 1.81 mg L⁻¹ MnCl₂ · 4H₂O, 0.222 mg L⁻¹ ZnSO₄ · 7H₂O, 0.39 mg L⁻¹ NaMoO₄ · 2H₂O, 0.079 mg L⁻¹ CuSO₄ · 5H₂O, and 49.4 μg L⁻¹ Co(NO₃)₂ · 6H₂O (Rippka [1988 (link)]), under continuous illumination at 50 or 200 μmol photons m⁻² s⁻¹ using white fluorescence bulbs (Life Look HGX and NHG; NEC, Tokyo, Japan) at 28 ± 2°C under atmospheric air conditions. For CO₂ enriched cultivation, cells were cultivated at 50 μmol photons m⁻² s⁻¹ and 1 or 2% CO₂ was supplied with a flow rate at 80 mL min⁻¹. Light intensity was measured in the middle of the culture using an LI-250A light meter (LI-COR, Lincoln, NE) equipped with an LI-190SA quantum sensor (LI-COR). Escherichia coli strain DH5α was used to propagate pBluescriptSK- and the apcE inactivation plasmids.

The axenic strain of Chlorella sorokiniana IPPAS C-1 was obtained from the collection of microalgae and cyanobacteria IPPAS (K.A. Timiryazev Institute of Plant Physiology, RAS, Moscow, Russia). The axenic culture was maintained on slants of Tamiya agarized medium [23 (link),24 (link)] in glass tubes at 22 °C under continuous illumination with cool white luminescent lamps of 30 μmol photons m⁻² s⁻¹. For the experiments, cells of C. sorokiniana were grown for 10–14 days in 300 mL Erlenmeyer flasks with 100 mL of ½ Tamiya modified medium [24 (link)] on an orbital shaker at room temperature under average illumination of 50 μmol photons m⁻² s⁻¹ from warm white light emitting diodes (LEDs). ½ Tamiya modified medium composition, g L⁻¹: NaNO₃—2.1; MgSO₄·7H₂O—1.25; KH₂PO₄—0.625; FeSO₄·7H₂O—0.009; EDTA—0.037; trace element solution (TES) 1 mL L⁻¹; TES composition, g L⁻¹: H₃BO₃—2.86; MnCl₂·4H₂O—1.81; ZnSO₄·7H₂O—0.222, MoO₃·2H₂O—0.018, NH₄VO₃—0.023.
All measurements of the irradiation level in the working volume of the PBRs and on the surface of the LED modules were recorded with a quantum meter LI-189 equipped with LI-190SA quantum sensor (LI-COR, Lincoln, NE, USA) in μmol photons m⁻² s⁻¹. Spectral composition of the light from LED was measured by LI-180 Spectrometer (LI-COR, Lincoln, NE, USA). Results of measurements were used to calculate the average irradiance on surfaces of PBRs.