Pilot-scale cultures were carried out in three identical single-use ‘hanging-bag’ (HB) photobioreactors (PBR) [29 (link)]. Each PBR was made from heat-sealed polythene layflat tubing (1000-gauge, UK packing, London, UK) with a width of 10.2 cm and a final working volume of 5 L. A late logarithmic-phase culture was used to inoculate the HBs to an initial optical density (OD) reading of 0.015 at 750 nm. The cells were grown in a temperature-controlled room at 24.5 °C under constant illumination provided by three light-emitting diode (LED) panels with an average light intensity of 140 µmol.m−2.s−1. The cultures were aerated and recirculated using a constant air flowrate of 1 L/min. No carbon dioxide was supplemented. The growth was monitored by off-line OD750 readings using semi-micro acrylic cuvettes with a path length of 10 mm and fresh TAP medium as blank.
The cultures were harvested after 3 days upon reaching the end of the logarithmic phase. Before harvesting, each HB was sampled for dry cell weight (DCW) measurements and immunoblotting (biological triplicates). The pellets for DCW were obtained from 50 mL samples after centrifugation (5000 g, 10 min, 12 °C) and stored at –20 °C for future freeze drying. For immunoblotting, 10 mL samples were centrifuged as previously described, snap-frozen in liquid nitrogen and stored at –80 °C for later analyses.
The cultures were harvested after 3 days upon reaching the end of the logarithmic phase. Before harvesting, each HB was sampled for dry cell weight (DCW) measurements and immunoblotting (biological triplicates). The pellets for DCW were obtained from 50 mL samples after centrifugation (5000 g, 10 min, 12 °C) and stored at –20 °C for future freeze drying. For immunoblotting, 10 mL samples were centrifuged as previously described, snap-frozen in liquid nitrogen and stored at –80 °C for later analyses.
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