Enhanced oil recovery by hydrophobins from Lecanicillium lecanii

•L. Lecanii produces hydrophobins in an 8.8L scale bioreactor.•Hydrophobins form stable oil in water emulsions.•Surface tension is preserved under aggressive oil well conditions.•Hydrophobins show 14% oil recovery. The hydrophobins (HFB)s are a class of proteins with high surface tension and thermostability which potential application in enhanced oil recovery (EOR). The entomopathogenic fungus Lecanicillium lecanii produced HFBs in an 8.8L-scale solid-state fermentation using polyurethane foams as inert support in three configurations. Additionally, crude enzyme with lipase activity was also produced and tested for EOR individually or in combination with HFBs. The polyurethane foam support in cubes attained the highest yield of class I HFB (17.3 ± 1%) and the highest lipase activity (3.6 ± 0.2 U/mg protein). These HFBs formed stable oil–water emulsions displaying an interfacial tension up to 7.6 ± 0.3 mN/m. The proteins were used in limestone cores under tertiary recovery oil well conditions to achieve up to 14% recovery.