title: CHANGES IN THE MORPHOLOGY AND POLYSACCHARIDE CONTENT OF MICROCYSTIS AERUGINOSA (CYANOBACTERIA) DURING FLAGELLATE GRAZING(1).
abstract: To investigate the changes in the morphology and polysaccharide content of Microcystis aeruginosa (Kütz.) Kütz. during flagellate grazing, cultures of M. aeruginosa were exposed to grazing Ochromonas sp. for a period of 9 d under controlled laboratory conditions. M. aeruginosa responded actively to flagellate grazing and formed colonies, most of which were made up of several or dozens of cells, suggesting that flagellate grazing may be one of the biotic factors responsible for colony formation in M. aeruginosa. When colonies were formed, the cell surface ultrastructure changed, and the polysaccharide layer on the surface of the cell wall became thicker. This change indicated that synthesis and secretion of extracellular polysaccharide (EPS) of M. aeruginosa cells increased under flagellate grazing pressure. The contents of soluble extracellular polysaccharide (sEPS), bound extracellular polysaccharide (bEPS), and total polysaccharide (TPS) in colonial cells of M. aeruginosa increased significantly compared with those in single cells. This finding suggested that the increased amount of EPS on the cell surface may play a role in keeping M. aeruginosa cells together to form colonies.
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China National Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, ChinaNational Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China National Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, ChinaNational Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Fanxiang
authors.initials: F
authors.lastname: Kong
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China National Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, ChinaNational Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Shi
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China National Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, ChinaNational Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China National Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, ChinaNational Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xing
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China National Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, ChinaNational Key Laboratory for Lake and Environment, Nanjing Institute of Geography and Limnology, the Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Huansheng
authors.initials: H
authors.lastname: Cao
keywords: Microcystis aeruginosa; colony formation; extracellular polysaccharide; flagellate; ultrastructure