Simultaneous extraction of proteins and DNA by an enzymatic treatment of the cell wall of Palmaria palmata (Rhodophyta)

The extraction of proteins and DNA from seaweed tissue is difficult due to the presence of cell wall anionic polysaccharides that, after cell disruption, remain in the extraction medium as hydrocolloidal compounds. These compounds increase medium viscosity, thus limiting access to and, consequently, quantification of the soluble macromolecules such as proteins or DNA. This study describes a protocol that enables the simultaneous isolation of proteins and DNA from the red seaweed Palmaria palmata. It is based upon a specific form of hydrolysis using a mixture of cellulase and xylanase at different concentrations. This approach was carried out on samples collected during April and July, seasons in which differences in protein content have previously been reported. Our results confirm this report and also show that protein yield depends on the enzyme concentration used. As for DNA, this enzymatic digestion results in a much higher yield compared with the control. However, no seasonal differences are found for DNA and there is no clear link between the increase in DNA yield and the enzyme mixture concentration.