M. Hassan et al., LIPID PRODUCTION BY AN UNSATURATED FATTY-ACID AUXOTROPH OF THE OLEAGINOUS YEAST APIOTRICHUM-CURVATUM GROWN IN SINGLE-STAGE CONTINUOUS-CULTURE, Applied microbiology and biotechnology, 40(4), 1993, pp. 483-488
An unsaturated fatty acid auxotroph of the oleaginous yeast Apiotrichu
m curvatum, named UfaM3, blocked in the conversion of stearic to oleic
acid was cultivated in single-stage continuous culture. The influence
of the consumed carbon to nitrogen ratios (C/N ratios, g g(-1)) obtai
ned at various dilution rates (D) on fatty acid (FA) accumulation and
its profiles were studied. In continuous culture in N-limited medium a
maximum FA accumulation of 45.6% (g g(-1) of dry biomass) was obtaine
d at an optimal D of 0.049 h(-1), recording an efficiency of substrate
conversion of 0.48 g g(-1) and 0.22 g g(-1) for biomass and lipids, r
espectively. The quality of lipid approached cocoa butter at an optima
l C/N ratio of between 20 and 30. The C/N ratio in the incoming medium
was 38.5 g g(-1) with 30 g l(-1) of glucose and both C and N sources
were completely consumed at a critical D of less than or equal to 0.07
h(-1). The stability of the mutant was demonstrated in the steady-sta
te conditions of the chemostat with regard to the FA composition of it
s lipids.