# Isolation of Phycobiliproteins from Thermosynechococcus PCC 6715 by Foam Fractionation in Batch and Continuous Modes

## TL;DR

This paper explores using foam fractionation to isolate valuable phycobiliproteins from a thermophilic cyanobacterium, comparing batch and continuous methods.

## Contribution

The study introduces foam fractionation in continuous mode for phycobiliprotein isolation, a novel approach not previously reported.

## Key findings

- Foam fractionation in continuous mode produced results comparable to batch mode for phycobiliprotein concentration.
- The method shows potential for separating different phycobiliproteins from each other.
- The process is suitable for large-scale application due to its effectiveness in diluted solutions.

## Abstract

Phycobiliproteins are recognized as potential bioactive compounds and described as highly valued natural products for industrial and biotechnological applications. Moreover, they have been observed to possess antioxidant, anticancer/antineoplastic, and anti-inflammatory activities. Therefore, the search for new methods of their extraction and isolation is still ongoing. Foam fractionation, a bubble separation technique that allows amphiphilic molecules to be separated from their aqueous solutions, is a promising but understudied method. The process may be carried out both under mild conditions that are suitable for proteins and also for diluted solutions. This paper presents the results of applying the foam fractionation process to concentrate and separate phycobiliproteins. Allo- and C-phycocyanin from a thermophilic Synechococcus PCC 6715 strain were used in extract form after biomass cultivation and disintegration. Two ways of running the process were investigated: batch mode and continuous mode, the latter of which has not been reported in the literature previously. The results indicate that the method can be applied on a larger scale, as the outcomes of the continuous mode processes were comparable to those of the batch mode. Moreover, the results indicate that the process provides, to a certain extent, the opportunity of separating phycobiliproteins from each other.