Suspended cultures were cultivated in 250mL Erlenmeyer flasks containing 100 mL of medium and were grown on an orbital shaker incubator at 25 ◦ C, under continuous light with an intensity of 70 ± 10 mol photons m−2 s−1 and a continuous agitation rate of 100 rpm. The headspace consisted of an air/CO2 mixture of 95/5%. Every three weeks 10 mL of a culture was transferred to a new flask containing fresh medium.