Mechanisms of Metal Resistance and Homeostasis in Haloarchaea

Table 2

Bioavailability of metal-ligand complexes in hypersaline conditions depending upon the nature of the complex formed.

Availability	Type of complex
Biologically unavailable	(i) Strong insoluble inorganic metal-chloro complexes (ZnCl2, CuCl2)
	(ii) Soluble not easily dissociable metal-chloro complexes (CdCl2)
	(iii) Biosorbed metal complexes (i.e., metals sorbed on a biotic ligand)
Biologically available	(i) Strong soluble lipophilic inorganic metal-chloro complexes (AgCl^2−, AgCl3^2−, AgCl4^3−, and HgCl2)
	(ii) Weak metal-chloro complexes (Fe, Co, Ni, and Mn)
	(iii) Metal complexes sorbed to abiotic ligands