Abstract
This dynamic proteome study describes the physiology of growth and survival of Deinococcus geothermalis,
in conditions simulating paper machine waters being aerobic, warm, and
low in carbon and manganese. The industrial environment of this species
differs from its natural habitats, geothermal springs and deep ocean
subsurfaces, by being highly exposed to oxygen. Quantitative proteome
analysis using two-dimensional gel electrophoresis and bioinformatic
tools showed expression change for 165 proteins, from which 47 were
assigned to a function. We propose that D. geothermalis
grew and survived in aerobic conditions by channeling central carbon
metabolism to pathways where mainly NADPH rather than NADH was retrieved
from the carbon source. A major part of the carbon substrate was
converted into succinate, which was not a fermentation product but
likely served combating reactive oxygen species (ROS). Transition from
growth to nongrowth resulted in downregulation of the oxidative
phosphorylation observed as reduced expression of V-type ATPase
responsible for ATP synthesis in D. geothermalis.
The battle against oxidative stress was seen as upregulation of
superoxide dismutase (Mn dependent) and catalase, as well as several
protein repair enzymes, including FeS cluster assembly proteins of the
iron-sulfur cluster assembly protein system, peptidylprolyl isomerase,
and chaperones. Addition of soluble Mn reinitiated respiration and
proliferation with concomitant acidification, indicating that aerobic
metabolism was restricted by access to manganese. We conclude that D. geothermalis
prefers to combat ROS using manganese-dependent enzymes, but when
manganese is not available central carbon metabolism is used to produce
ROS neutralizing metabolites at the expense of high utilization of
carbon substrate.
Original language | English |
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Pages (from-to) | 1552-1561 |
Number of pages | 10 |
Journal | Journal of Bacteriology |
Volume | 194 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2012 |
MoE publication type | A1 Journal article-refereed |