Study of effective utilization of the N₂-fixing terrestrial cyanobacterium, Nostoc commune based on the desiccation-responsible genes protected from desiccation stress under nitrogen deficiency.

Abstract

Using DNA microarray from a terrestrial cyanobacterium Anabaena sp. PCC7120, the typical desiccation-responsible genes were selected and the gene-disruptant were characterized. All of the disruptants showed low viability under desiccation using cells grown in nitrogen-free medium. These results may suggest that desiccation-tolerant genes contain function in N₂-fixation, are expressed irrespective of nitrogen content to protect desiccation sensitive N₂-fixing heterocyst and express to stabilize intra- and outer-cellular condition under desiccation.
Desiccation tolerant of N₂-fixing cyanobacterium, Nostoc commune is closely relative of the Anabaena. The Nostoc has ability to use scientific research for desiccation tolerance system, food and soil for plantation. These abilities expect to improve devastating soil to nutrient-rich soil including space agriculture. So it was tried to isolate the Nostoc and succeeded to cultivate the Nostoc axenically. To confirm ability of the Nostoc soil, the Nostoc was used plantation as nutrient containing plate. The result of difference plant growth between nitrogen-deficient plate and cyanobacterial mat is now in progress.