Transformation of H. pluvialis
H. pluvialis was transformed using the PDS-1000/He particle delivery system (BioRad) according to the manufacturer's instructions. 1 μg plasmid or linear DNA was used to coat 0.6 μm gold particles (BioRad). Two-four days after diluting stationary H. pluvialis culture (hereby, referred as 2–4 days old), 2–10 million cells, were plated onto TAP medium, 1.5% agarose and were bombarded from a distance of 6 cm using 1350 psi rupture disks. Two separate bombardments were conducted with each construct. DNA was omitted from control and bombarded once. After 1 night of recovery, cells were removed from the bombarded plates using TAP medium, and divided into two TAP plates supplement-
ed with either 2 or 5 μM norflurazon. Transformed colonies started to
appear after 8–28 days of incubation at optimal conditions of 20–
40 μmol photon × m−2 × s−1, 25°C