Salt acclimation of Nodularia spumigena CCY9414 - A cyanobacterium adapted to brackish water

Abstract

The toxic cyanobacterium Nodularia spumigena regularly forms large surface blooms in the central Baltic Sea. The Baltic Sea is characterized by a salinity gradient. We analyzed the salt acclimation of the strain N. spumigena CCY9414, the only Nodularia strain with a known genome sequence. N. spumigena CCY9414 showed a rather low salt tolerance range, displaying a growth optimum at 12.5 g NaCl l-1. Sucrose was identified as the major compatible solute. The expression of the sucrose-phosphate synthase gene was salt-stimulated, which indicates that the salt-induced sucrose accumulation could be regulated at the transcriptional level. Potassium ions and glutamate were also accumulated in Nodularia cells, especially at high salinities when sucrose levels were rather low. Our results indicate that N. spumigena CCY9414 represents a truly brackish-water-adapted cyanobacterial strain. © Inter-Research 2013.