Abstract
The oleaginous yeast Yarrowia lipolytica is an important industrial
microorganism used for the production of lipids, proteins and various
chemicals. The design of effective biotechnological processes with this
cell factory requires an in-depth knowledge of its metabolism. Here we
present a transcriptomic study of Y. lipolytica grown in the presence of
two important carbon sources, namely glycerol and glucose, as well as in
a mixture of both at different carbon to nitrogen ratios. It emerged
that the transcriptomic landscape of Y. lipolytica is more sensitive to
the nitrogen availability than to the utilized carbon source, as
evidenced by more genes being differentially expressed in lower carbon
to nitrogen ratio. In particular, expression of hexokinase (HXK1) is
significantly susceptible to changes in nitrogen concentrations.
Moreover, high HXK1 expression in low nitrogen seems to impact the
expression of other genes which are implicated in tricarboxylic acid
cycle and erythritol biosynthesis. We further show that expression of
HXK1 and two genes belonging to the sugar porter family might be
controlled by GATA-like zinc-finger proteins.