Continuous chromatographic biochemical reaction-separation

Abstract

Combined bioreaction separation studies have been carried out for the first time
on a moving port semi-continuous counter-current chromatographic reactor-separator (SCCR-S1) consisting of twelve 5.4cm id x 75cm long columns packed with calcium charged cross-linked polystyrene resin (KORELA V07C).
The inversion of sucrose to glucose and fructose in the presence of the enzyme invertase and the biochemIcal synthesis of dextran and fructose from sucrose in the presence of the enzyme dextransucrase were investigated. A dilute stream of the appropriate enzyme in deionised water was used as the eluent stream.
The effect of switch time, feed concentration, enzyme activity, eluent rate and
enzyme to feed concentration ratio on the combined bioreaction-separation were
investigated.
For the invertase reaction, at 20.77% w/v sucrose feed concentrations complete
conversions were achieved. The enzyme usage was 34% of the theoretical enzyme amount needed to convert an equivalent amount of sucrose over the same time period when using a conventional fermenter. The fructose rich (FRP) and glucose rich (GRP) product purities obtained were over 90%.
By operating at 35% w/v sucrose feed concentration and employing the product
splitting and recycling techniques, the total concentration and purity of the GRP increased from 32% w/v to 4.6% and from 92.3% to 95% respectively. The FRP concentration also increased from 1.82% w/v to 2.88% w/v.
A mathematical model was developed for the combined reaction-separation and
used to simulate the continuous inversion of sucrose and product separation using the SCCR-S1.
In the biosynthesis of dextran studies, 52% conversion of a 2% w/v sucrose
concentration feed was achieved. An average dextran molecular weight of 4 millIon was obtained in the dextran rich (DRP) product stream.
The enzyme dextransucrase was purifed successfully using centrifugation and
ultrafiltration techniques.

Date of Award	Dec 1989
Original language	English
Supervisor	George Ganetsos (Supervisor) & Philip E. Barker (Supervisor)