Cyanobacteria Metal Interactions: Requirements, Toxicity, and Ecological Implications

Abstract

The environmental health-related relevance of cyanobacteria is primarily related to their ability to produce a wide range of toxins, which are known to be hazardous to many organisms, including human beings. The occurrence of cyanobacterial blooms has been related to eutrophic surface water. In the bloom-forming process the levels of phosphorus and nitrogen have been well documented but information regarding concentrations of other chemicals (inorganic, organo-metallic, and organic) is still incipient. Several contaminants, like trace metals, elicit a variety of acute and chronic toxicity effects, but cyanobacteria also have the capability to accumulate, detoxify, or metabolize such substances, to some extent. The role of cyanobacterial exudates has been proved a means of both nutrient acquisition and detoxification. In addition, cyanobacteria are effective biological metal sorbents, representing an important sink for metals in aquatic environment. Understanding the fundamental physicochemical mechanisms of trace metal bio-uptake by cyanobacteria in natural systems is a step towards identifying under what conditions cyanobacterial growth is favored and to ascertain the mechanisms by which blooms (and toxin production) are triggered. In this review the cyanobacterial interactions with metals will be discussed, focusing on freshwater systems.

Metagenome of microorganisms associated with the toxic Cyanobacteria Microcystis aeruginosa analyzed using the 454 sequencing platform

“…Previous studies have suggested that the water bloom cyanobacteria M. aeruginosa can affect surrounding species, including zooplankton (Aleya et al, 2006), phytoplankton (Sedmak and Elersek, 2005) and microbes (Eiler and Bertilsson, 2004;Pope and Patel, 2008;Yoshida et al, 2006). Environmental elements (Baptista and Vasconcelos, 2006) and other species (Yoshida et al, 2006;Zhang et al, 2009) have also been shown to interact with the cyanobacteria. Currently, it is widely recognized that the dynamics of cyanobacterial harmful algal blooms (CHABs) is influenced by the amount, proportion, and chemical composition of the nitrogen and phosphorus that ends up in the water (Paerl, 2008).…”

Textural and Geochemical Features of Freshwater Microbialites From Laguna Bacalar, Quintana Roo, Mexico

“…Some are needed for the synthesis of particular enzymes, while others are utilized as nutrients (Silver 1998;Silva and Williams 2001;Baptista and Vasconcelos 2006). Both types of microbialites found in Laguna Bacalar display very similar major and trace element patterns; however, they do differ depending on the lake waters in which they grow (i.e., they show some elemental enrichment factors, Fig.…”

Heavy Metals Effect on Cyanobacteria Synechocystis aquatilis Study Using Absorption, Fluorescence, Flow Cytometry, and Photothermal Measurements

“…By biological indicators we understand plankton organisms, insects, mollusks, fish, plants, and birds [1]. Cyanobacteria (formerly known as blue-green algae) belong to the group of plankton organisms showing sensitivity to increased concentration of some heavy metals [8][9][10][11]. Cyanobacteria are thought to be among the evolutionarily oldest organisms; they can perform oxygenic photosynthesis and respiration simultaneously, and many of the species are able to fix nitrogen [12].…”