3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
bolome changes connected with proteome changes were
observed. Presence of exogenous stress factor led to overproduction
of carotenoids.
Fig. 2. 1D protein profiles – stressed r. glutinis; lane 1 – standard
6, 2 – proteome isolated by NaOh, 3 – proteome isolated
by SDS, 4 – proteome 2% NaCl, NaOh, 5 – 2 % NaCl, SDS,
6–7 – 5 % NaCl, 8–9 – 2 mM hydrogen peroxide, 10–11 – 5 mM
peroxide; 12, 13 – standards 4, 5
a b
Fig. 3. Protein profiles of rhodotorula glutinis a) control b) peroxide
stress
a b
Fig. 4. Protein profiles of rhodotorula rubra a) control
b) peroxide stress
s648
Conclusions
In this work proteome changes in two Rhodotorula strains
grown under salt and peroxide stress was studied. Isolation
of proteins from red yeast cells is extremely complicated
by unusual character of cell wall. Combination of several
glycosidases and glucuronidases was the most common procedure.
However, this method can lead to high interference of
lytic enzymes during electrophoretic separation. In this work
isolation of proteome using detergent SDS or alcalic lysis
(naOH) combined by mechanical disintegration by glass
beads was optimized.
1D electrophoresis PAGE-SDS exhibited relatively
good separation of proteins. Better results were obtained by
alcaline lysis.
2D electrophoresis was done using stressed yeasts Rhodotorula
glutinis and Rhodotorula rubra. Proteomic profiles
differed according to strain and stress type.
In R. glutinis proteome more spots were evaluated.
Significant 2D proteome changes were observed mainly in
peroxide stress. Relatively well-balanced response to stress
influence was observed in presence of 2 % salt; it seems that
R.glutinis cells could exhibit long-term adaptation to this
stress factor.
In R. rubra proteome less protein spots were detected
and changes in stress conditions were not such intensive as
in R.glutinis.
Proteome changes corresponded to some metabolome
changes in Rhodotorula cells. Presence of some exogenous
stress factor led to important overproduction of beta-carotene
and ergosterol. Both these industrially significant metabolites
are induced by the same way through the common isoprenoid
pathway. In presence of salt well-balanced adaptation
mechanisms were probably activated and, thus, salt stress
could be used industrially to enhanced production of betacarotene
enriched biomass. R. rubra produced substantially
lower amount of beta-carotene, this production was quite
independent on stress factor.
Further experiments are needed for detailed characterization
of molecular changes connected with exogenous stress
and for identification of proteins involved in stress response
of red yeasts.
This work was supported by projects MSM 0021630501
of the Czech Ministry of Education, Youth and Sport and
IAA400310506 of Grant Agency of the Academy of Sciences
of the Czech Republic.
REFEREnCES
1. Halienova A., Marova I., Carnecka M., Konečná
H., Hanusova V., Hezinova V.: J. Biotechnol. 131,
202 (2007).