title: Field studies on the environmental factors in controlling microcystin production in the subtropical shallow lakes of the Yangtze River.
abstract: Microcystin (MC) problem made more and more care about in China, intercellular MC (Int-MC) and cellular MC (Cel-MC) were important contents to reflect the producing-MC ability by cyanobacteria and by lakes. To study the correlations between Int-MC, Cel-MC concentration and biological and environmental factors, eight cyanobacterial blooming lakes were studied in the middle and lower reaches of the Yangtze River. Microcystin-RR (MC-RR) and Microcystin-LR (MC-LR) were the primary toxin variants in our data. From the linear correlations between MC and environmental factors, cellular-YR had significant correlation with most of chemical factors except total nitrogen (TN) and the ratio of total nitrogen and total phosphorus (TN/TP), most intracellular MC analogues had significant correlations with total dissolved nitrogen (TDN), ammonium (NH (4) (+) ), nitrite (NO (2) (-) ), TP, total dissolved phosphorus (TDP), Microcystis. From the canonal correspondence analysis, Int-MC concentrations were closely related with the chemical and biological factors, such as TP, total organic carbon (TOC), chlorophyll a (Chl a), Microcystis biomass, et al. While Cel-MC contents, especially Cel-RR and Cel-LR, were closely related with light environmental in the lakes such as water depth and transparence.
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, Institute of Hydrobiology, Chinese Academy of Science, Wuhan, 430072, People's Republic of China.
authors.forename: S
authors.initials: S
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.forename: P
authors.initials: P
authors.lastname: Xie
authors.forename: L
authors.initials: L
authors.lastname: Ni
authors.forename: J
authors.initials: J
authors.lastname: Xu
mesh_terms: D018533:Biomass; D002681:China; D000458:Cyanobacteria / Q000737:chemistry / Q000378:metabolism; D005068:Eutrophication / Q000502:physiology*; D005618:Fresh Water / Q000032:analysis; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D052998:Microcystins / Q000032:analysis / Q000096:biosynthesis*; D013056:Spectrophotometry, Ultraviolet; D014876:Water Pollution / Q000517:prevention & control*
chemical_list: D007202:Indicators and Reagents; D052998:Microcystins