A new cultivation method for microbial oil production: cell pelletization and lipid accumulation by Mucor circinelloides
1 State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, China
2 Department of Bioproducts and Biosystems Engineering, University of Minnesota, MN, USA
3 Department of Bioproducts and Biosystems Engineering, University of Minnesota, 316 BAE, 1390 Eckles Avenue, St. Paul, MN 55108-6005, USA
Biotechnology for Biofuels 2011, 4:15 doi:10.1186/1754-6834-4-15Published: 2 June 2011
The recent energy crisis has triggered significant attention on the microbial synthesis of lipids, which comprise the raw material for biodiesel production. Microbial oil accumulation with filamentous fungi has great potential because filamentous fungi can form pellets during cell growth, and these pellets are much easier to harvest from cell broth. This paper focuses on the cell pelletization process of the oleaginous Mucor circinelloides. We have studied the effect of various cultural conditions on pelletized cell growth and lipid accumulation. This study is the first to report that pH adjustment during cell growth plays a key role in pellet formation of M. circinelloides and describes a handy method by which to induce cell pelletization in submerged fungal cultivation. Our study reveals that cell growth and lipid production are not significantly affected by pelletization and that lipid accumulation is triggered at stressed conditions, such as a high carbon-to-nitrogen ratio and high temperature.