(117v) Effect of 1,3-Dimethyl-2-Imidazolidinone in Lipid Production of Rhodotorula Glutinis

Authors: 
Correa-Negrón, F. M., University of Puerto Rico Mayaguez
French, T., Mississippi State University
Hernandez, R., Mississippi State University

Previous
studies demonstrated that the oleaginous yeast Rhodotorula glutinis produces
about 50% of its dry weight as lipids in glucose rich and nitrogen limited
environment and could be used for biodiesel production.  The use of waste paper
as carbon source helps getting the glucose rich environment needed through a
hydrolysis process.  Since the ink embedded in waste paper cannot be economically
removed by hydrolysis, this study focused on determining the effect of 1,3-Dimethyl-2-imidazolidinone
(a major component of black printing dyes) in lipid production of R. glutinis
Cultivation of this yeast at 30°C under nitrogen limited conditions and glucose
concentration of 60 grams per liter results in production of 53-55% dry cell weight
as lipids for control cultures after 144 hr.  Same conditions were used for
experimental cultures, but with concentrations of 1.0 and 0.5M of
1,3-Dimethyl-2-imidazolidinone.  This ink component at 1M decreases lipid
production of R. glutinis by 5%.  The lipid profile obtained indicates
that at 1M the ink component affects the yeast's metabolism decreasing the saturated
lipid obtained by 4.5%.  At concentration of 0.5M, appreciable effects on the
yeast's metabolism were not observed.  Significant percents of lipids were
obtained from the yeast recommending this method for biodiesel production from
waste paper.