Mechanisms for copper tolerance in Amphora coffeaeformis-internal and external binding

Copper Transfer and Influence on a Marine Food Chain

“…Brown et al (1988) observed physical exclusion of metal ions due to reduced cell membrane permeability, and internal immobilization by the formation of "copper" bodies and by the binding of metal ions to cell exudates (Xue and Sigg 1990). Most studies have demonstrated that Dunaliella cells exhibit a higher resistance to heavy metals than other algae, explained by several factors: a) lower uptake of heavy metals, b) better detoxification mechanisms, c) internal complexation by glycerol, and d) lower activity coefficients of polyvalent cations in saline and hypersaline media of comparable ionic strength (Gimmler et al 1991).…”

“…1. Brown et al (1988) suggested that D. tertiolecta is a species that is able to exclude metals. The results of this study showed a probable different mechanism where copper can be taken up by the D. tertiolecta and then released as shown in Figure 2.…”

“…Exclusion of copper from the cell interior has been suggested as the primary tolerance mechanism in Scenedesmus acutus (Twiss et al 1993). Other processes such as internal detoxification might also be occurring (Brown et al 1988). …”

Toxicity and bioaccumulation of copper in three green microalgal species

“…The effective concentration of heavy metal that inhibits 50% microalgal growth at 96 h (96 h EC50) is widely used as an index of toxicity (Hornstrom, 1990). One mechanism of tolerance by algae is physiological exclusion of metal ions due to reduced cell membrane permeability (Brown et al, 1988). Internal metal immobilization by the formation of copper bodies can also occur (Nassiri et al, 1997).…”

Experiences with Some Toxic and Relatively Accessible Heavy Metals on the Survival and Biomass Production of Amphora costata W. Smith

“…Responses to different heavy metals treated with numerous representatives of the marine/freshwater phytoplankton includes their growth characteristics, morphological and physiological changes and other phenomenon in insitu and invivo conditions are published by different workers such as on morphology (Joux-Arab et al 2000), growth rate (Brown et al 1988), several other physiological processes (Brand et al 1983(Brand et al , 1986) of benthic and/or planktonic microalgae in laboratory conditions and as well as lakes (Munawar and Legner 1993), Bays (Ahner et al 1994;Luoma 1998), coastal waters (Ahner et al 1997;Bu-Olayan et al 2001) and open waters (Magi et al 2005).…”