Bioresource Technology, Volume 183, 2015, Pages 18-24.
Zhenhua Ruan1, Whitney Hollinshead2, Christine Isaguirre1, Yinjie J. Tang2, Wei Liaoa,Yan Liu1Show Affiliations
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48823, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO 63130, USA
Oleaginous fungus Mortierella isabellina showed excellent lipid conversion on non-detoxified lignocellulosic hydrolysate. This study investigated the effects of inhibitory compounds (furfural, hydroxymethylfurfural, and ferulic and coumaric acids) in lignocellulosic hydrolysate on Mortierella isabellina growth and lipid production. M. isabellina can tolerate furfural (∼1 g/L), hydroxymethylfurfural (∼2.5 g/L), ferulic (∼0.5 g/L) and coumaric acid (∼0.5 g/L) with normal growth rates. Synergistic effect of these inhibitors (2 g/L furfural, 0.4 g/L hydroxymethylfurfural, 0.02 g/L ferulic acid and 0.02 g/L coumaric acid) moderately reduces total fungal growth (by 28%), while the presence of these inhibitors has minor impact on cell lipid contents and lipid profiles. In the presence of inhibitory compounds, 13C-tracing has revealed that Mortierella isabellina can simultaneously utilize glucose and acetate, and acetate is mainly assimilated for synthesis of lipid and TCA cycle amino acids. The results also demonstrate that glucose has strong catabolite repression for xylose utilization for biomass and lipid production in the presence of inhibitors.