Kinetics of Microbial Mass and Lipid Production by Rhodotorula Glutinis From Hydrolyzate of Switchgrass

Microbial oils derived from lignocellulosic biomass could potentially be a cheap source of biodiesel. Previous experiments showed that Rhodotorula glutinis (ATCC 15125) could convert the sugars in acid hydrolysate of switchgrass into microbial lipids for use as a biodiesel feedstock. The objective of this research is to investigate kinetic behaviors of the microbial mass and lipid production by R. glutinis using hydrolyzate of switchgrss as sole carbon and energy source.  In the experiments, the C to N ratio and C to P ratio as well as the temperature were evaluated on the microbial growth and lipid production of R. glutinis. The lipid content in the cells reached 32% of the cell dry mass. Effects of temperature,  nitrogen and phosphate concentration on the net specific growth rate were also studied. In the kinetic models, temperature, substrate concentrations of carbon, nitrogen and phosphorus will be considered in the models for both biomass and lipid production. Also in the study of the models, the overall inhibition of the byproducts from hydrolysis was also be investigated in terms of the microbial growth and lipid production rate.