However, the observation of periodic and synchronized oscillations
in laboratory yeast glycolysis in the late 1950s, subsequently,
brought immense focus to biochemists interested in understanding
the self-organizing response (Fig.5)[22]. Each yeast, in a sus-
pended culture, was able to synchronize its oscillation with other
yeasts collectively to gain phase with each other. The yeast was one
of the first evidence under laboratory conditions that showed order
arising among cell cultures under carefully controlled biological
parameters (culture volume, aeration rate, fermenter agitation
rate, etc.). However, the continuous oscillations are sensitive to
laboratory conditions and can be destroyed if any of the control
parameters was not precisely maintained. Thus, in the words of
Nobel laureate Ilya Prigogine, living organisms can be considered
dissipative systems, where energy and matter are exchanged to
generate order [23].
The observation of self-organizing behaviors in simple labora-
tory experiments led many theoretical biologists to investigate
nonlinear approaches to model biological networks.3.2 Belousov–
Zhabotinsky Reaction
and the Brusselator
While studying the Kreb’s cycle to identify an inorganic analog, Boris
Belousov, in the 1950s, accidently observed periodic spatial patterns
when he mixed citric acid, bromate, and cerium with sulfuric acid
solution (Fig.6). Inspired by this, Anatol M. Zhabotinskii further
worked on similar self-organizing behaviors using malonic acids,
resulting in non-equilibrium thermodynamics and the establishment
of a nonlinear chemical system (Belousov–Zhabotinsky or B-Z reac-
tion), where oscillatory behavior or multi-stable states are produced
autocatalytically through feedback regulation of one of its species.Fig. 5Oscillatory Cellular Dynamics in Yeast. Glycolytic (NADH) oscillations are induced by adding KOH.
Figure adapted from [22]
182 Kumar Selvarajoo