Hydrobiologia

, Volume 596, Issue 1, pp 47–55

Different tolerances and responses to low temperature and darkness between waterbloom forming cyanobacterium Microcystis and a green alga Scenedesmus

Primary Research Paper

DOI: 10.1007/s10750-007-9056-7

Cite this article as:
Wu, Z., Song, L. & Li, R. Hydrobiologia (2008) 596: 47. doi:10.1007/s10750-007-9056-7

Abstract

The dynamics of planktonic cyanobacteria in eutrophicated freshwaters play an important role in formation of annual summer blooms, yet overwintering mechanisms of these water bloom forming cyanobacteria remain unknown. The responses to darkness and low temperature of three strains (unicellular Microcystis aeruginosa FACHB-905, colonial M. aeruginosa FACHB-938, and a green alga Scenedesmusquadricauda FACHB-45) were investigated in the present study. After a 30-day incubation under darkness and low temperature, cell morphology, cell numbers, chlorophyll a, photosynthetic activity (ETRmax and Ik), and malodialdehyde (MDA) content exhibited significant changes in Scenedesmus. In contrast, Microcystis aeruginosa cells did not change markedly in morphology, chlorophyll a, photosynthetic activity, and MDA content. The stress caused by low temperature and darkness resulted in an increase of the antioxidative enzyme-catalase (CAT) in all three strains. When the three strains re-grew under routine cultivated condition subjected to darkness and low temperature, specific growth rate of Scenedesmus was lower than that of Microcystis. Flow cytometry (FCM) examination indicated that two distinct types of metabolic response to darkness and low temperature existed in the three strains. The results from the present study reveal that the cyanobacterium Microcystis, especially colonial Microcystis, has greater endurance and adaptation ability to the stress of darkness and low temperature than the green alga Scenedesmus.

Keywords

DarknessLow temperatureResponseToleranceMicrocystisScenedesmus

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Institute of HydrobiologyChinese Academy of SciencesWuhanP.R. China