Xylanase mass transfer studies in aqueous two-phase systems using spray and sieve plate columns

Abstract

Aqueous two-phase systems (ATPSs) have long been used for biomolecule partitioning; these systems offer the possibility of using continuous or semicontinuous extraction processes. They require relatively simple equipment like spray or sieve plate columns that can be adapted for use in ATPSs. The aim of this work was to study the semicontinuous extraction of a model enzyme, xylanase, in spray and sieve plate columns, since, unlike centrifugal contactors, the cost of construction and maintenance of this equipment is low and it is easy to operate. For the spray column, the dispersed phase hold-up and overall mass transfer coefficients K(D) a were evaluated for different column heights and for different superficial velocities of the dispersed phase (light phase). Results indicated that an increase in superficial velocity in the range of 0-0.18 mm/s of the dispersed phase had a positive effect on K(D) a and on hold-up in all column heights studied, 75, 161 and 246 mm. For the same superficial velocity of the dispersed phase, the larger the hold-up was, the shorter the column. For the sieve plate column, the effects of the superficial velocity of the dispersed phase and the number of plates were also studied. Results showed that the K(D) a and hold-up increased with an increase in both parameters. The selectivity of separation of xylanase and BSA (model contaminant) was very high, since 60% of the enzyme was extracted in the light phase, whereas no significant amount of BSA was extracted. The possibility of using the sieve plate column in continuous operation for enzyme extraction was studied because previous work had only addressed the semicontinuous extraction of enzyme. The residence time distribution of the PEG phase using different superficial velocities of the salt phase was studied in continuous operation. The time required to reach the steady state was 40 min, and 70% of the xylanase was recovered. It was found that the Modified Power Spline software was well adjusted to the experimental results.

An integrated practical implementation of continuous aqueous two‐phase systems for the recovery of human IgG: From the microdevice to a multistage bench‐scale mixer‐settler device

“…As stated previously in different microfluidics approaches , this platform allowed the use of minimal reagent quantities and a quick evaluation of a larger number of ATPS compositions, just adjusting the phase components flow ratios. In this case, use of the microfluidic device confirmed the IgG partitioning behavior observed by several authors where it mainly partitions toward the PEG‐rich phase, in comparison to the ATPS without NaCl in which major recovery is achieved in the phosphate‐rich phase, but with lower yields. The microfluidic approach proposed here effectively used to perform a quick and general screening of the main partition behavior of a molecule of interest, could be a trustworthy tool to accelerate the bioprocess design.…”

Mass transfer in aqueous two-phases system packed column

“…The superficial velocity of PEG phase was kept in 0.12 mm/s because the overall mass transfer coefficient was kept constant above this superficial velocity [9]. The influence of different contact times between the two phases was studied for the three kinds of packings.…”

Single stage aqueous two-phase extraction for monoclonal antibody purification from cell supernatant

“…Major advantage of ATPE in comparison to chromatography is a continuous application at high capacity which is comparably easy to scale up leading to low process time and cost [1]. Aqueous two-phase systems (ATPS) conventionally comprise two hydrophilic polymers or a hydrophilic polymer and a salt dissolved in water.…”