The Effects of Different Salt Concentrations on the Biochemical Contents of Gracilaria gracilis Greville (Rhodophyta)

Abstract

It has been known that, climate change causes changes in marine water salinity. Since salinity is one of the major factors on osmoregulation and ion concentration of algae, marinealgal community will be effected by salinity changes. Gracilaria gracilis samples were collected from Izmir Bay on December 2014. After 2 days adjustment period in the laboratory conditions, the algae samples were divided into 4 groups and each group were cultured indifferent salinity concentrations (10‰, 25‰, 37‰ control group, 48‰) for 7days. On Day 0, 2, 5 and 7, small pieces of samples collected from each groupafterwards total protein, phycocyanin, phycoerythrin and chlorophyll aintegrity and catalase activity were analyzed. Phycocyanin, phycoerythrin andchlorophyll a levels and catalase activity showed variations according toexposure time and salinity concentrations. Except for the catalase activity,all the parameters were decreased by the end of the 7th day at differentsalinities. The highest catalase activity was observed on the last day of theexperiment in all groups which shows the salinity stress increasement accordingto exposure time. Gracilaria graciliswas not able to adapt both hiposalinity and hypersalinity conditions.