The changes of nitric oxide production during the growth of Microcystis aerugrinosa

This study characterized the changes of nitric oxide (NO) production during the growth of Microcystis aerugrinosa, a cyanobacterium which usually cause cyanobacterial blooms. Results showed a drastic NO release accompanying with cell density and Chl-a content sharp rises when M. aerugrinosa grew from fifth day to sixth day. Moreover, high N:P ratio accelerated the cyanobacterial growth and NO burst. Sodium nitroprusside, an exogenous NO donor, promoted M. aerugrinosa growth with the optimal concentration of 0.1 mg/L. Experiments by supplementing with sodium nitrite and l-arginine demonstrated NO production in M. aerugrinosa cells was mainly through nitrate reductase (NR) pathway while minorly through NO synthase pathway. All these data suggested M. aerugrinosa produced increasing NO during its growth mainly by NR pathway, during which NO positively regulated the growth of M. aerugrinosa.

► We study NO release during M. aerugrinosa growth.
► A drastic NO release from M. aerugrinosa accompanies with cell density and Chl-a sharp rise.
► High N:P ratio accelerates the sharp increase of cell density, Chl-a content and NO burst.
► NO donor promotes M. aerugrinosa growth with the optimal concentration of 0.1 mg/L.
► NO production in M. aerugrinosa cells is mainly through nitrate reductase pathway.