Experimental Study of Biodegradation of Ethanol and Toluene Vapors

When the concept of inhibited co-metabolism is applied to bioremediation of
mixtures of toluene and ethanol, it is assumed that biomass formed from ethanol and
toluene acts as an inhibitor (Bailey and Ollis, 1986; Chang et al, 1993; Bielefeldt and
Stensel, 1999). In addition to the reaction Equations (5-3), (5-10) and (5-11) for ethanol
bioremediation, toluene catabolism is represented by Equation (5-44) on a 1 C-mol
basis, which was derived from the toluene pathway (Davey and Gibson, 1974; Wackett,
2004, see Appendix A-III):
CH
8 / 7
8 3 12
r 12
+ H
2O
+ O2
+ NAD ⎯⎯→
4 NADH
2
+
2
7 7 7
7
CO
(5-44)
The stoichiometric matrix, θ
et , for four reactions (5-3), (5-10), (5-11) and (5-44) can be
written as
r e
r t
r x
-1.27 -1 0 0
0 0 0 -1
1 0 0 0
3
θ
et = r o2
= 0 0 -0.5 − (5-45)
7
0.27 1 0 1
r co2
rATP
-α1E -0.5 δ 0
12
r
NADH
1.81 3 -1
7
The reaction rate vector ν for four reactions (5-3), (5-10), (5-11), and (5-44) can be
written as:
ν 1
ν r = ν 2 (5-46)
ν 3
ν 4
112