We have been developing an approach to monitoring environmental water bodies for the presence of cyanobacteria. The established approach to monitoring water for aqueous vegetation and cyanobacteria is to separately extract chlorophyll for the estimation of all aquatic vegetation and to extract phycocyanin for the estimation of cyanobacteria. The approach reported here uses a biphasic system composed of octanol and water for the simultaneous extraction of chlorophyll and phycocyanin from aquatic vegetation, resulting in the separation of the two pigments into different phases; chlorophyll in the upper octanol layer, and phycocyanin in the lower aqueous layer. Such separation of the two pigments allows for more sensitive detection of either pigment. A potential flaw in this approach is that phycocyanin (a protein) exposure to octanol during the extraction process tends to reduce the blue color used to measure the phycocyanin. We have now discovered that this loss of blue color, which we assume to be due to denaturation of the phycocyanin, can be prevented by making the aqueous phase 3M fructose. Others have shown a similar protective effect of fructose against protein denaturation. The data presented here show the protective effect observed in the extraction of phycocyanin from different strains of cyanobacteria. We also show relative detection limits for phycocyanin and chlorophyll by both optical density and intrinsic fluorescence measurements. In contrast, neither glycerol nor polyethylene glycol has this protective effect. The basis for the protective effect of fructose is under investigation. This work is funded by the Biology Department of East Georgia State College.


USG STEM IV grant for undergraduate research to East Georgia State College

This document is currently not available here.