Culture volume and agitation speed affected
the dissolved oxygen profile of B. bassiana cultures as well as
their growth parameters. Higher aeration rates were achieved
by lowering culture volume, increasing agitation speed and by
their combination, resulting in extended oxygen availability as
noted by the dissolved oxygen curves (Fig. 1). Apart from the
B. bassiana isolates, the fermentation time where cultures
reached 50% dissolved oxygen (DO50) were 4.5–7.3 h higher
in cultures grown at 50 mL compared with cultures grown at
100mL, and 6.8–9.6 h in cultures grown at 350 rpmcompared
with cultures grown at 175 rpm (Table S1 in the Electronic
supplementary material; Fig. 1). Furthermore, B. bassiana
cultures of both isolates showed similar DO50 values. Dissolved
oxygen levels remained low (