Multiphase Bioreactor Design

The inversion (hydrolysis) of saccharose by invertase to produce an equimolecular
mixture of frutose and glucose, has also been investigated (Cantarella et al., 1989;
Nakajima et al., 1989, 1993). The product, known as invert sugar has sweetness
comparable to saccharose and can be used, for instance, to produce artificial honey
(Belitz & Grosch, 1987).
A more unusual reaction involving oligosaccharides has been recently described by
Okada and coworkers (1994b). The authors used a cyclodextrin glucanotransferase
covalently immobilised on the surface of a capillary membrane to catalyse the
intermolecular transglycosylation of cyclodextrin with maltooligosaccharides, glucose
and saccharose. The modified cyclodextrins thus obtained are potentially useful in
various industrial fields such as food processing, medicine and cosmetics (Okada et al.,
1994b).

Other Applications

Apart from the examples described above, other applications of membrane reactors have
been investigated (Table 6.10). At DEGUSSA AG (Leuchtenberger et al., 1984) a pilot
scale (40 1) reactor coupled to 0.5 m^2 hollow fibre modules was used in a recycle
configuration for the production of L-amino acids (L-methionine and L-phenylalanine)
by enzymatic

Table 6.9 Conversion of oligosaccharides

Enzyme-reaction description Reference

Conversion of O-nitrophenyl-β-D-galactopyranoside by -
galactosidase

Kim & Chang, 1983b

Hydrolysis of maltose by amyloglucosidase immobilised by
electrostatic forces in a MR

Furusaki & Asai, 1983

Hydrolysis of lactose catalysed by β-galactosidase in a hollow fibre
membrane reactor

Jones et al., 1984

Hydrolysis of lactose catalysed by β-galactosidase in a membrane
reactor with pulsatile flow

Park et al., 1985

Conversion of maltose into hydrogen peroxide by the sequential use
of glucoamylase and glucose oxidase

Bardelleti & Coulet, 1987

Synthesis of 2-naphtol glucuronide by UDP-glucuronyltransferase
with cofactor (UDPGA) addition

Tegtmeier et al., 1988

Hydrolysis of lactose catalysed by β-galactosidase in a capillary bed
reactor

Peterson et al., 1989a,

1989b

Study of product inhibition in the hydrolysis of cellobiose catalysed
by β-glucosidase from Aspergillus niger

Alfani et al., 1990

Process optimisation of a membrane reactor for the lactose
conversion catalysed by β-galactosidase

Czermark et al., 1991

Hydrolysis of lactose in skim milk catalysed byβ-galactosidase from Bakken et al., 1992

Multiphase bioreactor design 176