Page 53 - Biofuels Refining and Performance

36 Chapter One

nature of the luminescent light varies in color and intensity; but chem-
ical pathways are, to a great extent, common. The chemical products
responsible for giving out different colors are different and are not yet
fully known.
5
A heat-labile simple protein enzyme luciferase (MW 10 ) makes a
complex (luciferyl adenylate E) with reduced luciferin, in the presence
2
of ATP (Mg ), which subsequently breaks down into different products
in the presence of molecular oxygen. This results in the excitation of
luciferin to a high-energy state. On return of the same to the ground
state, emission of visible light produces bioluminescence (see Fig. 1.13).
2
LH ATP (Mg ) E → LH AMP E PPi
2
2
LH AMP E O → Products Light
2
2
The phenomenon appears to be insignificant but a substantial supply
2
of luciferin, ATP (Mg ), and a little enzyme can deliver an appreciable
luminescence of practical use. Whether luciferin, luciferase, and ATP
may also be harvested from animal resources, or the chemical compo-
nents may be synthesized economically and the enzyme can be pro-
cured from flies, remains a matter of investigation and development.
Like bee-keeping, culture of “fireflies” is very likely to become a prof-
itable art. The dream of producing high voltage by animal tissues, imi-
tating the electric eel, may come true in the near future; the
fundamentals are known, but economic viability is not assured, hence
not discussed here.

N S H S H
Y– H
S N
HO C–OH N C–OH
|| ||
O H O
Y
Luciferin (dehydro) LH 2 (reduced luciferin)

S
Y– OH
|
N
C—O — P— O —Ribose-Adenine
|| ||
O O
LH -Adenylate
2
Figure 1.13 Firefly bioluminescence.