SmartFlow Technologies

Isolation and concentration of small molecules

Optimization Procedure

The SmartFlow® filter WORKS Isolation of small molecules optimization procedure from SFT is intended for separating a target small molecule such as a sugar or an amino acid from a fermentation or extraction process stream. The procedure is designed to have the small molecule pass freely through the membrane while cells, proteins, and large molecular weight process stream components are retained by the membrane.

This optimization procedure uses ultrafiltration membranes that retain the cells and allow the small molecules to pass freely through the membrane. The process can often be run at high flux rates by using a high MW UF membrane that retains the cells but still permits the free passage of the small broth components.


This Isolation of small molecules protocol is intended for isolating a small molecule from a fermentation broth.

This process has been repeatedly implemented with consistent success in E.coli and Pichia fermentations with products under 5,000 molecular weight. This process works best with secreted target molecules, but acceptable results will be obtained with lysed cell starting material.
The initial step isolates the target molecule from the fermentation broth by using a 10 or 30 kD regenerated cellulose membrane to pass the target molecule freely into the permeate and retain the cells, large molecular weight broth components, and any accumulated cell debris. The protocol calls for the fermentation broth to be concentrated to 5X prior to starting the diafiltration.

Case Study

Process development scientists at a specialty chemical company examined isolating amino acids produced in a bacterial fermentation process with OPTISEP® filter modules. The objective of the program was to develop a process that maintained many characteristics of the current manufacturing process.