Extracting lipids from oleaginous microbial cells in a cost effective and environmentally compatible manner
remains a critical challenge in developing manufacturing paradigms for advanced liquid biofuels. In
this study, a new approach using microbial growth inhibitors from lignocellulose-derived feedstocks was
used to extract lipids efficiently from wet cell mass of the oleaginous bacterium Rhodococcus opacus
MITXM-61. Nine common lignocellulose-derived inhibitors for treatment of cells prior to solvent extraction
were used and evaluated for their efficiency of lipid extraction from the cells. When the inhibitors
were individually examined, formic acid and furfural showed the highest extraction efficiency of lipids
from wet cell mass. Multiple extractions of lipids with methanol from wet cell mass pretreated with combined
common inhibitors or hardwood hydrolysate comprising lignocellulose-derived inhibitors resulted
in lipid recovery of greater than 85% of total lipids, a 1.7-fold increase of lipid extraction as compared to
those in the absence of the inhibitors.