Abstract
Synechocystis sp. strain PCC6803 can grow under the wide-ranging environmental stress conditions. Over the course of our study on membrane transport system involved in adaptive response to salinity stress, we found that Synechocystis produced biofilm (exopollysaccharide) at the high salt environment. With increase of amount of biofilm formed around cells, growth rate of the cells decreased. It is known that polyamines play an important role in the cell division and protection against salt stress. To examine the relationship between polyamine content and the cell growth rate, we measured polyamins content. It is found that salinity stress deceased the content of spermidine. Therefore we generated the mutants at putative arginine decarboxylase which is one of the key enzymes in polyamine biosynthesis process in order to measure the amount of biofilm by environmental changes. The mutant exhibited a high rate of biofilm compared with the wild type. To further analyze the regulatory mechanism on the biofilm formation, we are in progress on gene screening of salt stress sensor proteins.
