beneath the saturation concentration) to predict substrate and product concentration-time
profiles in a Lewis cell with biocatalyst present. These can then be compared with those
measured experimentally. This technique is valid both for microbial and enzymically
catalysed biotransformations.
Figure 5.5 is a plot of data for the hydrolysis of benzyl acetate by pig liver esterase in
a two-liquid phase system in a 24.2 m−^1 (aqueous phase basis) specific interfacial area
Lewis cell. The data show substrate and product concentration-time profiles with 0.01 g
Figure 5.5 Hydrolysis of benzyl
acetate by pig liver esterase (0.01 g
1 −^1 ) in a Lewis cell reactor showing
the changes in the aqueous phase
concentrations of benzyl acetate, [Sab]
( ) and reactor concentrations of
benzyl alcohol (on an aqueous phase
basis), [Pr] (Φ+1) (∆, ) with time for
two starting conditions, [Sab] ( )
and All points are the
average of three determinations
( ). Redrawn from Woodley
et al. (1991a).
l−^1 pig liver esterase in 200 ml of aqueous phase catalysing the hydrolysis of 300 ml of
benzyl acetate (lower organic phase). Both phases were well mixed without disturbing
the flat liquid-liquid interface using two turbine impellers each rotating at 120 rpm. The
measured substrate mass transfer coefficient in the absence of any biotransformation was
1.8×10−^8 s−^1. Close agreement was observed between the steady-state aqueous phase
Advances in the selection and design of two-liquid phase biocatalytic reactors 133