The microalgae Botryococcus braunii is widely recognized as a potentially important biofuel-feedstock
whose commercial exploitation is limited by difficulties with its cultivation and harvesting. In this study,
two B. braunii strains, Kossou-4 and Overjuyo-3 were successfully cultured at a 500 l-scale for 60-days.
Harvesting by bio-flocculation with Aspergillus fumigatus at an optimum ratio of 1:40 of fungus to
microalgal culture resulted in up to 98% recovery of biomass in the two strains. Ultimate analysis (C,
N, H, S, ash, high heating value) and pyrolysis (analytical and preparative pyrolysis and GC–MS assays)
showed that co-harvesting with fungi did not cause any impairment of the feedstock value of the
microalgal biomass. This work represents the first report on the successful culturing and harvesting of
these strains at a 500 l-scale using bio-flocculation. The use of A. fumigatus represents an efficient and
economical method for the harvest of B. braunii for biofuel production.